Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1 | /* SIP extension for IP connection tracking. |
| 2 | * |
| 3 | * (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar> |
| 4 | * based on RR's ip_conntrack_ftp.c and other modules. |
Patrick McHardy | f49e1aa | 2008-03-25 20:27:05 -0700 | [diff] [blame] | 5 | * (C) 2007 United Security Providers |
| 6 | * (C) 2007, 2008 Patrick McHardy <kaber@trash.net> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
Pablo Neira Ayuso | ad6d950 | 2016-01-03 22:41:24 +0100 | [diff] [blame] | 13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 14 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 15 | #include <linux/module.h> |
| 16 | #include <linux/ctype.h> |
| 17 | #include <linux/skbuff.h> |
| 18 | #include <linux/inet.h> |
| 19 | #include <linux/in.h> |
| 20 | #include <linux/udp.h> |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 21 | #include <linux/tcp.h> |
Yasuyuki Kozakai | 1863f09 | 2006-12-02 22:12:54 -0800 | [diff] [blame] | 22 | #include <linux/netfilter.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 23 | |
| 24 | #include <net/netfilter/nf_conntrack.h> |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 25 | #include <net/netfilter/nf_conntrack_core.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 26 | #include <net/netfilter/nf_conntrack_expect.h> |
| 27 | #include <net/netfilter/nf_conntrack_helper.h> |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 28 | #include <net/netfilter/nf_conntrack_zones.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 29 | #include <linux/netfilter/nf_conntrack_sip.h> |
| 30 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 31 | MODULE_LICENSE("GPL"); |
| 32 | MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>"); |
| 33 | MODULE_DESCRIPTION("SIP connection tracking helper"); |
| 34 | MODULE_ALIAS("ip_conntrack_sip"); |
Pablo Neira Ayuso | 4dc06f9 | 2008-11-17 16:01:42 +0100 | [diff] [blame] | 35 | MODULE_ALIAS_NFCT_HELPER("sip"); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 36 | |
| 37 | #define MAX_PORTS 8 |
| 38 | static unsigned short ports[MAX_PORTS]; |
Stephen Hemminger | 2f0d2f1 | 2008-01-31 04:08:10 -0800 | [diff] [blame] | 39 | static unsigned int ports_c; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 40 | module_param_array(ports, ushort, &ports_c, 0400); |
| 41 | MODULE_PARM_DESC(ports, "port numbers of SIP servers"); |
| 42 | |
| 43 | static unsigned int sip_timeout __read_mostly = SIP_TIMEOUT; |
| 44 | module_param(sip_timeout, uint, 0600); |
| 45 | MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session"); |
| 46 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 47 | static int sip_direct_signalling __read_mostly = 1; |
| 48 | module_param(sip_direct_signalling, int, 0600); |
| 49 | MODULE_PARM_DESC(sip_direct_signalling, "expect incoming calls from registrar " |
| 50 | "only (default 1)"); |
| 51 | |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 52 | static int sip_direct_media __read_mostly = 1; |
| 53 | module_param(sip_direct_media, int, 0600); |
| 54 | MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling " |
| 55 | "endpoints only (default 1)"); |
| 56 | |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 57 | const struct nf_nat_sip_hooks *nf_nat_sip_hooks; |
| 58 | EXPORT_SYMBOL_GPL(nf_nat_sip_hooks); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 59 | |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 60 | static int string_len(const struct nf_conn *ct, const char *dptr, |
| 61 | const char *limit, int *shift) |
| 62 | { |
| 63 | int len = 0; |
| 64 | |
| 65 | while (dptr < limit && isalpha(*dptr)) { |
| 66 | dptr++; |
| 67 | len++; |
| 68 | } |
| 69 | return len; |
| 70 | } |
| 71 | |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 72 | static int digits_len(const struct nf_conn *ct, const char *dptr, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 73 | const char *limit, int *shift) |
| 74 | { |
| 75 | int len = 0; |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 76 | while (dptr < limit && isdigit(*dptr)) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 77 | dptr++; |
| 78 | len++; |
| 79 | } |
| 80 | return len; |
| 81 | } |
| 82 | |
Simon Horman | 001985b | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 83 | static int iswordc(const char c) |
| 84 | { |
| 85 | if (isalnum(c) || c == '!' || c == '"' || c == '%' || |
Marco Angaroni | f0608ce | 2016-08-30 18:48:24 +0200 | [diff] [blame] | 86 | (c >= '(' && c <= '+') || c == ':' || c == '<' || c == '>' || |
Simon Horman | 001985b | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 87 | c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' || |
Marco Angaroni | f0608ce | 2016-08-30 18:48:24 +0200 | [diff] [blame] | 88 | c == '{' || c == '}' || c == '~' || (c >= '-' && c <= '/') || |
| 89 | c == '\'') |
Simon Horman | 001985b | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 90 | return 1; |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | static int word_len(const char *dptr, const char *limit) |
| 95 | { |
| 96 | int len = 0; |
| 97 | while (dptr < limit && iswordc(*dptr)) { |
| 98 | dptr++; |
| 99 | len++; |
| 100 | } |
| 101 | return len; |
| 102 | } |
| 103 | |
| 104 | static int callid_len(const struct nf_conn *ct, const char *dptr, |
| 105 | const char *limit, int *shift) |
| 106 | { |
| 107 | int len, domain_len; |
| 108 | |
| 109 | len = word_len(dptr, limit); |
| 110 | dptr += len; |
| 111 | if (!len || dptr == limit || *dptr != '@') |
| 112 | return len; |
| 113 | dptr++; |
| 114 | len++; |
| 115 | |
| 116 | domain_len = word_len(dptr, limit); |
| 117 | if (!domain_len) |
| 118 | return 0; |
| 119 | return len + domain_len; |
| 120 | } |
| 121 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 122 | /* get media type + port length */ |
| 123 | static int media_len(const struct nf_conn *ct, const char *dptr, |
| 124 | const char *limit, int *shift) |
| 125 | { |
| 126 | int len = string_len(ct, dptr, limit, shift); |
| 127 | |
| 128 | dptr += len; |
| 129 | if (dptr >= limit || *dptr != ' ') |
| 130 | return 0; |
| 131 | len++; |
| 132 | dptr++; |
| 133 | |
| 134 | return len + digits_len(ct, dptr, limit, shift); |
| 135 | } |
| 136 | |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 137 | static int sip_parse_addr(const struct nf_conn *ct, const char *cp, |
| 138 | const char **endp, union nf_inet_addr *addr, |
| 139 | const char *limit, bool delim) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 140 | { |
| 141 | const char *end; |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 142 | int ret; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 143 | |
Simon Horman | 5adbb9f | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 144 | if (!ct) |
| 145 | return 0; |
| 146 | |
Patrick McHardy | fa913dd | 2008-04-14 11:15:45 +0200 | [diff] [blame] | 147 | memset(addr, 0, sizeof(*addr)); |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 148 | switch (nf_ct_l3num(ct)) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 149 | case AF_INET: |
| 150 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 151 | if (ret == 0) |
| 152 | return 0; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 153 | break; |
| 154 | case AF_INET6: |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 155 | if (cp < limit && *cp == '[') |
| 156 | cp++; |
| 157 | else if (delim) |
| 158 | return 0; |
| 159 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 160 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 161 | if (ret == 0) |
| 162 | return 0; |
| 163 | |
| 164 | if (end < limit && *end == ']') |
| 165 | end++; |
| 166 | else if (delim) |
| 167 | return 0; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 168 | break; |
| 169 | default: |
| 170 | BUG(); |
| 171 | } |
| 172 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 173 | if (endp) |
| 174 | *endp = end; |
| 175 | return 1; |
| 176 | } |
| 177 | |
| 178 | /* skip ip address. returns its length. */ |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 179 | static int epaddr_len(const struct nf_conn *ct, const char *dptr, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 180 | const char *limit, int *shift) |
| 181 | { |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 182 | union nf_inet_addr addr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 183 | const char *aux = dptr; |
| 184 | |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 185 | if (!sip_parse_addr(ct, dptr, &dptr, &addr, limit, true)) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 186 | pr_debug("ip: %s parse failed.!\n", dptr); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | /* Port number */ |
| 191 | if (*dptr == ':') { |
| 192 | dptr++; |
| 193 | dptr += digits_len(ct, dptr, limit, shift); |
| 194 | } |
| 195 | return dptr - aux; |
| 196 | } |
| 197 | |
| 198 | /* get address length, skiping user info. */ |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 199 | static int skp_epaddr_len(const struct nf_conn *ct, const char *dptr, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 200 | const char *limit, int *shift) |
| 201 | { |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 202 | const char *start = dptr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 203 | int s = *shift; |
| 204 | |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 205 | /* Search for @, but stop at the end of the line. |
| 206 | * We are inside a sip: URI, so we don't need to worry about |
| 207 | * continuation lines. */ |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 208 | while (dptr < limit && |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 209 | *dptr != '@' && *dptr != '\r' && *dptr != '\n') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 210 | (*shift)++; |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 211 | dptr++; |
| 212 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 213 | |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 214 | if (dptr < limit && *dptr == '@') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 215 | dptr++; |
| 216 | (*shift)++; |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 217 | } else { |
| 218 | dptr = start; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 219 | *shift = s; |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 220 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 221 | |
| 222 | return epaddr_len(ct, dptr, limit, shift); |
| 223 | } |
| 224 | |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 225 | /* Parse a SIP request line of the form: |
| 226 | * |
| 227 | * Request-Line = Method SP Request-URI SP SIP-Version CRLF |
| 228 | * |
| 229 | * and return the offset and length of the address contained in the Request-URI. |
| 230 | */ |
| 231 | int ct_sip_parse_request(const struct nf_conn *ct, |
| 232 | const char *dptr, unsigned int datalen, |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 233 | unsigned int *matchoff, unsigned int *matchlen, |
| 234 | union nf_inet_addr *addr, __be16 *port) |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 235 | { |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 236 | const char *start = dptr, *limit = dptr + datalen, *end; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 237 | unsigned int mlen; |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 238 | unsigned int p; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 239 | int shift = 0; |
| 240 | |
| 241 | /* Skip method and following whitespace */ |
| 242 | mlen = string_len(ct, dptr, limit, NULL); |
| 243 | if (!mlen) |
| 244 | return 0; |
| 245 | dptr += mlen; |
| 246 | if (++dptr >= limit) |
| 247 | return 0; |
| 248 | |
| 249 | /* Find SIP URI */ |
Patrick McHardy | 54101f4 | 2010-02-11 12:23:12 +0100 | [diff] [blame] | 250 | for (; dptr < limit - strlen("sip:"); dptr++) { |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 251 | if (*dptr == '\r' || *dptr == '\n') |
| 252 | return -1; |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 253 | if (strncasecmp(dptr, "sip:", strlen("sip:")) == 0) { |
Patrick McHardy | 54101f4 | 2010-02-11 12:23:12 +0100 | [diff] [blame] | 254 | dptr += strlen("sip:"); |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 255 | break; |
Patrick McHardy | 54101f4 | 2010-02-11 12:23:12 +0100 | [diff] [blame] | 256 | } |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 257 | } |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 258 | if (!skp_epaddr_len(ct, dptr, limit, &shift)) |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 259 | return 0; |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 260 | dptr += shift; |
| 261 | |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 262 | if (!sip_parse_addr(ct, dptr, &end, addr, limit, true)) |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 263 | return -1; |
| 264 | if (end < limit && *end == ':') { |
| 265 | end++; |
| 266 | p = simple_strtoul(end, (char **)&end, 10); |
| 267 | if (p < 1024 || p > 65535) |
| 268 | return -1; |
| 269 | *port = htons(p); |
| 270 | } else |
| 271 | *port = htons(SIP_PORT); |
| 272 | |
| 273 | if (end == dptr) |
| 274 | return 0; |
| 275 | *matchoff = dptr - start; |
| 276 | *matchlen = end - dptr; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 277 | return 1; |
| 278 | } |
| 279 | EXPORT_SYMBOL_GPL(ct_sip_parse_request); |
| 280 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 281 | /* SIP header parsing: SIP headers are located at the beginning of a line, but |
| 282 | * may span several lines, in which case the continuation lines begin with a |
| 283 | * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or |
| 284 | * CRLF, RFC 3261 allows only CRLF, we support both. |
| 285 | * |
| 286 | * Headers are followed by (optionally) whitespace, a colon, again (optionally) |
| 287 | * whitespace and the values. Whitespace in this context means any amount of |
| 288 | * tabs, spaces and continuation lines, which are treated as a single whitespace |
| 289 | * character. |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 290 | * |
Daniel Mack | 3ad2f3f | 2010-02-03 08:01:28 +0800 | [diff] [blame] | 291 | * Some headers may appear multiple times. A comma separated list of values is |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 292 | * equivalent to multiple headers. |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 293 | */ |
| 294 | static const struct sip_header ct_sip_hdrs[] = { |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 295 | [SIP_HDR_CSEQ] = SIP_HDR("CSeq", NULL, NULL, digits_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 296 | [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len), |
| 297 | [SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len), |
| 298 | [SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len), |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 299 | [SIP_HDR_VIA_UDP] = SIP_HDR("Via", "v", "UDP ", epaddr_len), |
| 300 | [SIP_HDR_VIA_TCP] = SIP_HDR("Via", "v", "TCP ", epaddr_len), |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 301 | [SIP_HDR_EXPIRES] = SIP_HDR("Expires", NULL, NULL, digits_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 302 | [SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len), |
Simon Horman | 001985b | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 303 | [SIP_HDR_CALL_ID] = SIP_HDR("Call-Id", "i", NULL, callid_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 304 | }; |
| 305 | |
| 306 | static const char *sip_follow_continuation(const char *dptr, const char *limit) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 307 | { |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 308 | /* Walk past newline */ |
| 309 | if (++dptr >= limit) |
| 310 | return NULL; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 311 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 312 | /* Skip '\n' in CR LF */ |
| 313 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 314 | if (++dptr >= limit) |
| 315 | return NULL; |
| 316 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 317 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 318 | /* Continuation line? */ |
| 319 | if (*dptr != ' ' && *dptr != '\t') |
| 320 | return NULL; |
| 321 | |
| 322 | /* skip leading whitespace */ |
| 323 | for (; dptr < limit; dptr++) { |
| 324 | if (*dptr != ' ' && *dptr != '\t') |
| 325 | break; |
| 326 | } |
| 327 | return dptr; |
| 328 | } |
| 329 | |
| 330 | static const char *sip_skip_whitespace(const char *dptr, const char *limit) |
| 331 | { |
| 332 | for (; dptr < limit; dptr++) { |
Marco Angaroni | 1bcabc8 | 2016-08-30 18:52:22 +0200 | [diff] [blame] | 333 | if (*dptr == ' ' || *dptr == '\t') |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 334 | continue; |
| 335 | if (*dptr != '\r' && *dptr != '\n') |
| 336 | break; |
| 337 | dptr = sip_follow_continuation(dptr, limit); |
Marco Angaroni | 68cb9fe | 2016-08-30 18:48:19 +0200 | [diff] [blame] | 338 | break; |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 339 | } |
| 340 | return dptr; |
| 341 | } |
| 342 | |
| 343 | /* Search within a SIP header value, dealing with continuation lines */ |
| 344 | static const char *ct_sip_header_search(const char *dptr, const char *limit, |
| 345 | const char *needle, unsigned int len) |
| 346 | { |
| 347 | for (limit -= len; dptr < limit; dptr++) { |
| 348 | if (*dptr == '\r' || *dptr == '\n') { |
| 349 | dptr = sip_follow_continuation(dptr, limit); |
| 350 | if (dptr == NULL) |
| 351 | break; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 352 | continue; |
| 353 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 354 | |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 355 | if (strncasecmp(dptr, needle, len) == 0) |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 356 | return dptr; |
| 357 | } |
| 358 | return NULL; |
| 359 | } |
| 360 | |
| 361 | int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, |
| 362 | unsigned int dataoff, unsigned int datalen, |
| 363 | enum sip_header_types type, |
| 364 | unsigned int *matchoff, unsigned int *matchlen) |
| 365 | { |
| 366 | const struct sip_header *hdr = &ct_sip_hdrs[type]; |
| 367 | const char *start = dptr, *limit = dptr + datalen; |
| 368 | int shift = 0; |
| 369 | |
| 370 | for (dptr += dataoff; dptr < limit; dptr++) { |
| 371 | /* Find beginning of line */ |
| 372 | if (*dptr != '\r' && *dptr != '\n') |
| 373 | continue; |
| 374 | if (++dptr >= limit) |
| 375 | break; |
| 376 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 377 | if (++dptr >= limit) |
| 378 | break; |
| 379 | } |
| 380 | |
| 381 | /* Skip continuation lines */ |
| 382 | if (*dptr == ' ' || *dptr == '\t') |
| 383 | continue; |
| 384 | |
| 385 | /* Find header. Compact headers must be followed by a |
| 386 | * non-alphabetic character to avoid mismatches. */ |
| 387 | if (limit - dptr >= hdr->len && |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 388 | strncasecmp(dptr, hdr->name, hdr->len) == 0) |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 389 | dptr += hdr->len; |
| 390 | else if (hdr->cname && limit - dptr >= hdr->clen + 1 && |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 391 | strncasecmp(dptr, hdr->cname, hdr->clen) == 0 && |
Patrick McHardy | 135d018 | 2010-01-19 19:06:59 +0100 | [diff] [blame] | 392 | !isalpha(*(dptr + hdr->clen))) |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 393 | dptr += hdr->clen; |
| 394 | else |
| 395 | continue; |
| 396 | |
| 397 | /* Find and skip colon */ |
| 398 | dptr = sip_skip_whitespace(dptr, limit); |
| 399 | if (dptr == NULL) |
| 400 | break; |
| 401 | if (*dptr != ':' || ++dptr >= limit) |
| 402 | break; |
| 403 | |
| 404 | /* Skip whitespace after colon */ |
| 405 | dptr = sip_skip_whitespace(dptr, limit); |
| 406 | if (dptr == NULL) |
| 407 | break; |
| 408 | |
| 409 | *matchoff = dptr - start; |
| 410 | if (hdr->search) { |
| 411 | dptr = ct_sip_header_search(dptr, limit, hdr->search, |
| 412 | hdr->slen); |
| 413 | if (!dptr) |
| 414 | return -1; |
| 415 | dptr += hdr->slen; |
| 416 | } |
| 417 | |
| 418 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 419 | if (!*matchlen) |
| 420 | return -1; |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 421 | *matchoff = dptr - start + shift; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 422 | return 1; |
| 423 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 424 | return 0; |
| 425 | } |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 426 | EXPORT_SYMBOL_GPL(ct_sip_get_header); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 427 | |
Daniel Mack | 3ad2f3f | 2010-02-03 08:01:28 +0800 | [diff] [blame] | 428 | /* Get next header field in a list of comma separated values */ |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 429 | static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr, |
| 430 | unsigned int dataoff, unsigned int datalen, |
| 431 | enum sip_header_types type, |
| 432 | unsigned int *matchoff, unsigned int *matchlen) |
| 433 | { |
| 434 | const struct sip_header *hdr = &ct_sip_hdrs[type]; |
| 435 | const char *start = dptr, *limit = dptr + datalen; |
| 436 | int shift = 0; |
| 437 | |
| 438 | dptr += dataoff; |
| 439 | |
| 440 | dptr = ct_sip_header_search(dptr, limit, ",", strlen(",")); |
| 441 | if (!dptr) |
| 442 | return 0; |
| 443 | |
| 444 | dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen); |
| 445 | if (!dptr) |
| 446 | return 0; |
| 447 | dptr += hdr->slen; |
| 448 | |
| 449 | *matchoff = dptr - start; |
| 450 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
| 451 | if (!*matchlen) |
| 452 | return -1; |
| 453 | *matchoff += shift; |
| 454 | return 1; |
| 455 | } |
| 456 | |
| 457 | /* Walk through headers until a parsable one is found or no header of the |
| 458 | * given type is left. */ |
| 459 | static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, |
| 460 | unsigned int dataoff, unsigned int datalen, |
| 461 | enum sip_header_types type, int *in_header, |
| 462 | unsigned int *matchoff, unsigned int *matchlen) |
| 463 | { |
| 464 | int ret; |
| 465 | |
| 466 | if (in_header && *in_header) { |
| 467 | while (1) { |
| 468 | ret = ct_sip_next_header(ct, dptr, dataoff, datalen, |
| 469 | type, matchoff, matchlen); |
| 470 | if (ret > 0) |
| 471 | return ret; |
| 472 | if (ret == 0) |
| 473 | break; |
| 474 | dataoff += *matchoff; |
| 475 | } |
| 476 | *in_header = 0; |
| 477 | } |
| 478 | |
| 479 | while (1) { |
| 480 | ret = ct_sip_get_header(ct, dptr, dataoff, datalen, |
| 481 | type, matchoff, matchlen); |
| 482 | if (ret > 0) |
| 483 | break; |
| 484 | if (ret == 0) |
| 485 | return ret; |
| 486 | dataoff += *matchoff; |
| 487 | } |
| 488 | |
| 489 | if (in_header) |
| 490 | *in_header = 1; |
| 491 | return 1; |
| 492 | } |
| 493 | |
| 494 | /* Locate a SIP header, parse the URI and return the offset and length of |
| 495 | * the address as well as the address and port themselves. A stream of |
| 496 | * headers can be parsed by handing in a non-NULL datalen and in_header |
| 497 | * pointer. |
| 498 | */ |
| 499 | int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, |
| 500 | unsigned int *dataoff, unsigned int datalen, |
| 501 | enum sip_header_types type, int *in_header, |
| 502 | unsigned int *matchoff, unsigned int *matchlen, |
| 503 | union nf_inet_addr *addr, __be16 *port) |
| 504 | { |
| 505 | const char *c, *limit = dptr + datalen; |
| 506 | unsigned int p; |
| 507 | int ret; |
| 508 | |
| 509 | ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen, |
| 510 | type, in_header, matchoff, matchlen); |
| 511 | WARN_ON(ret < 0); |
| 512 | if (ret == 0) |
| 513 | return ret; |
| 514 | |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 515 | if (!sip_parse_addr(ct, dptr + *matchoff, &c, addr, limit, true)) |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 516 | return -1; |
| 517 | if (*c == ':') { |
| 518 | c++; |
| 519 | p = simple_strtoul(c, (char **)&c, 10); |
| 520 | if (p < 1024 || p > 65535) |
| 521 | return -1; |
| 522 | *port = htons(p); |
| 523 | } else |
| 524 | *port = htons(SIP_PORT); |
| 525 | |
| 526 | if (dataoff) |
| 527 | *dataoff = c - dptr; |
| 528 | return 1; |
| 529 | } |
| 530 | EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri); |
| 531 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 532 | static int ct_sip_parse_param(const struct nf_conn *ct, const char *dptr, |
| 533 | unsigned int dataoff, unsigned int datalen, |
| 534 | const char *name, |
| 535 | unsigned int *matchoff, unsigned int *matchlen) |
| 536 | { |
| 537 | const char *limit = dptr + datalen; |
| 538 | const char *start; |
| 539 | const char *end; |
| 540 | |
| 541 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 542 | if (!limit) |
| 543 | limit = dptr + datalen; |
| 544 | |
| 545 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 546 | if (!start) |
| 547 | return 0; |
| 548 | start += strlen(name); |
| 549 | |
| 550 | end = ct_sip_header_search(start, limit, ";", strlen(";")); |
| 551 | if (!end) |
| 552 | end = limit; |
| 553 | |
| 554 | *matchoff = start - dptr; |
| 555 | *matchlen = end - start; |
| 556 | return 1; |
| 557 | } |
| 558 | |
Patrick McHardy | 2bbb211 | 2008-03-25 20:24:24 -0700 | [diff] [blame] | 559 | /* Parse address from header parameter and return address, offset and length */ |
| 560 | int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, |
| 561 | unsigned int dataoff, unsigned int datalen, |
| 562 | const char *name, |
| 563 | unsigned int *matchoff, unsigned int *matchlen, |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 564 | union nf_inet_addr *addr, bool delim) |
Patrick McHardy | 2bbb211 | 2008-03-25 20:24:24 -0700 | [diff] [blame] | 565 | { |
| 566 | const char *limit = dptr + datalen; |
| 567 | const char *start, *end; |
| 568 | |
| 569 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 570 | if (!limit) |
| 571 | limit = dptr + datalen; |
| 572 | |
| 573 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 574 | if (!start) |
| 575 | return 0; |
| 576 | |
| 577 | start += strlen(name); |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 578 | if (!sip_parse_addr(ct, start, &end, addr, limit, delim)) |
Patrick McHardy | 2bbb211 | 2008-03-25 20:24:24 -0700 | [diff] [blame] | 579 | return 0; |
| 580 | *matchoff = start - dptr; |
| 581 | *matchlen = end - start; |
| 582 | return 1; |
| 583 | } |
| 584 | EXPORT_SYMBOL_GPL(ct_sip_parse_address_param); |
| 585 | |
| 586 | /* Parse numerical header parameter and return value, offset and length */ |
| 587 | int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr, |
| 588 | unsigned int dataoff, unsigned int datalen, |
| 589 | const char *name, |
| 590 | unsigned int *matchoff, unsigned int *matchlen, |
| 591 | unsigned int *val) |
| 592 | { |
| 593 | const char *limit = dptr + datalen; |
| 594 | const char *start; |
| 595 | char *end; |
| 596 | |
| 597 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 598 | if (!limit) |
| 599 | limit = dptr + datalen; |
| 600 | |
| 601 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 602 | if (!start) |
| 603 | return 0; |
| 604 | |
| 605 | start += strlen(name); |
| 606 | *val = simple_strtoul(start, &end, 0); |
| 607 | if (start == end) |
| 608 | return 0; |
| 609 | if (matchoff && matchlen) { |
| 610 | *matchoff = start - dptr; |
| 611 | *matchlen = end - start; |
| 612 | } |
| 613 | return 1; |
| 614 | } |
| 615 | EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param); |
| 616 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 617 | static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, |
| 618 | unsigned int dataoff, unsigned int datalen, |
| 619 | u8 *proto) |
| 620 | { |
| 621 | unsigned int matchoff, matchlen; |
| 622 | |
| 623 | if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=", |
| 624 | &matchoff, &matchlen)) { |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 625 | if (!strncasecmp(dptr + matchoff, "TCP", strlen("TCP"))) |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 626 | *proto = IPPROTO_TCP; |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 627 | else if (!strncasecmp(dptr + matchoff, "UDP", strlen("UDP"))) |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 628 | *proto = IPPROTO_UDP; |
| 629 | else |
| 630 | return 0; |
| 631 | |
| 632 | if (*proto != nf_ct_protonum(ct)) |
| 633 | return 0; |
| 634 | } else |
| 635 | *proto = nf_ct_protonum(ct); |
| 636 | |
| 637 | return 1; |
| 638 | } |
| 639 | |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 640 | static int sdp_parse_addr(const struct nf_conn *ct, const char *cp, |
| 641 | const char **endp, union nf_inet_addr *addr, |
| 642 | const char *limit) |
| 643 | { |
| 644 | const char *end; |
| 645 | int ret; |
| 646 | |
| 647 | memset(addr, 0, sizeof(*addr)); |
| 648 | switch (nf_ct_l3num(ct)) { |
| 649 | case AF_INET: |
| 650 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); |
| 651 | break; |
| 652 | case AF_INET6: |
| 653 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
| 654 | break; |
| 655 | default: |
| 656 | BUG(); |
| 657 | } |
| 658 | |
| 659 | if (ret == 0) |
| 660 | return 0; |
| 661 | if (endp) |
| 662 | *endp = end; |
| 663 | return 1; |
| 664 | } |
| 665 | |
| 666 | /* skip ip address. returns its length. */ |
| 667 | static int sdp_addr_len(const struct nf_conn *ct, const char *dptr, |
| 668 | const char *limit, int *shift) |
| 669 | { |
| 670 | union nf_inet_addr addr; |
| 671 | const char *aux = dptr; |
| 672 | |
| 673 | if (!sdp_parse_addr(ct, dptr, &dptr, &addr, limit)) { |
| 674 | pr_debug("ip: %s parse failed.!\n", dptr); |
| 675 | return 0; |
| 676 | } |
| 677 | |
| 678 | return dptr - aux; |
| 679 | } |
| 680 | |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 681 | /* SDP header parsing: a SDP session description contains an ordered set of |
| 682 | * headers, starting with a section containing general session parameters, |
| 683 | * optionally followed by multiple media descriptions. |
| 684 | * |
| 685 | * SDP headers always start at the beginning of a line. According to RFC 2327: |
| 686 | * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should |
| 687 | * be tolerant and also accept records terminated with a single newline |
| 688 | * character". We handle both cases. |
| 689 | */ |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 690 | static const struct sip_header ct_sdp_hdrs_v4[] = { |
| 691 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), |
| 692 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP4 ", sdp_addr_len), |
| 693 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP4 ", sdp_addr_len), |
| 694 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), |
| 695 | }; |
| 696 | |
| 697 | static const struct sip_header ct_sdp_hdrs_v6[] = { |
| 698 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), |
| 699 | [SDP_HDR_OWNER] = SDP_HDR("o=", "IN IP6 ", sdp_addr_len), |
| 700 | [SDP_HDR_CONNECTION] = SDP_HDR("c=", "IN IP6 ", sdp_addr_len), |
| 701 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 702 | }; |
| 703 | |
| 704 | /* Linear string search within SDP header values */ |
| 705 | static const char *ct_sdp_header_search(const char *dptr, const char *limit, |
| 706 | const char *needle, unsigned int len) |
| 707 | { |
| 708 | for (limit -= len; dptr < limit; dptr++) { |
| 709 | if (*dptr == '\r' || *dptr == '\n') |
| 710 | break; |
| 711 | if (strncmp(dptr, needle, len) == 0) |
| 712 | return dptr; |
| 713 | } |
| 714 | return NULL; |
| 715 | } |
| 716 | |
| 717 | /* Locate a SDP header (optionally a substring within the header value), |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 718 | * optionally stopping at the first occurrence of the term header, parse |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 719 | * it and return the offset and length of the data we're interested in. |
| 720 | */ |
| 721 | int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr, |
| 722 | unsigned int dataoff, unsigned int datalen, |
| 723 | enum sdp_header_types type, |
| 724 | enum sdp_header_types term, |
| 725 | unsigned int *matchoff, unsigned int *matchlen) |
| 726 | { |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 727 | const struct sip_header *hdrs, *hdr, *thdr; |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 728 | const char *start = dptr, *limit = dptr + datalen; |
| 729 | int shift = 0; |
| 730 | |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 731 | hdrs = nf_ct_l3num(ct) == NFPROTO_IPV4 ? ct_sdp_hdrs_v4 : ct_sdp_hdrs_v6; |
| 732 | hdr = &hdrs[type]; |
| 733 | thdr = &hdrs[term]; |
| 734 | |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 735 | for (dptr += dataoff; dptr < limit; dptr++) { |
| 736 | /* Find beginning of line */ |
| 737 | if (*dptr != '\r' && *dptr != '\n') |
| 738 | continue; |
| 739 | if (++dptr >= limit) |
| 740 | break; |
| 741 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 742 | if (++dptr >= limit) |
| 743 | break; |
| 744 | } |
| 745 | |
| 746 | if (term != SDP_HDR_UNSPEC && |
| 747 | limit - dptr >= thdr->len && |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 748 | strncasecmp(dptr, thdr->name, thdr->len) == 0) |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 749 | break; |
| 750 | else if (limit - dptr >= hdr->len && |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 751 | strncasecmp(dptr, hdr->name, hdr->len) == 0) |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 752 | dptr += hdr->len; |
| 753 | else |
| 754 | continue; |
| 755 | |
| 756 | *matchoff = dptr - start; |
| 757 | if (hdr->search) { |
| 758 | dptr = ct_sdp_header_search(dptr, limit, hdr->search, |
| 759 | hdr->slen); |
| 760 | if (!dptr) |
| 761 | return -1; |
| 762 | dptr += hdr->slen; |
| 763 | } |
| 764 | |
| 765 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
| 766 | if (!*matchlen) |
| 767 | return -1; |
| 768 | *matchoff = dptr - start + shift; |
| 769 | return 1; |
| 770 | } |
| 771 | return 0; |
| 772 | } |
| 773 | EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header); |
| 774 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 775 | static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr, |
| 776 | unsigned int dataoff, unsigned int datalen, |
| 777 | enum sdp_header_types type, |
| 778 | enum sdp_header_types term, |
| 779 | unsigned int *matchoff, unsigned int *matchlen, |
| 780 | union nf_inet_addr *addr) |
| 781 | { |
| 782 | int ret; |
| 783 | |
| 784 | ret = ct_sip_get_sdp_header(ct, dptr, dataoff, datalen, type, term, |
| 785 | matchoff, matchlen); |
| 786 | if (ret <= 0) |
| 787 | return ret; |
| 788 | |
Patrick McHardy | 02b69cb | 2012-08-09 10:08:46 +0000 | [diff] [blame] | 789 | if (!sdp_parse_addr(ct, dptr + *matchoff, NULL, addr, |
| 790 | dptr + *matchoff + *matchlen)) |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 791 | return -1; |
| 792 | return 1; |
| 793 | } |
| 794 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 795 | static int refresh_signalling_expectation(struct nf_conn *ct, |
| 796 | union nf_inet_addr *addr, |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 797 | u8 proto, __be16 port, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 798 | unsigned int expires) |
| 799 | { |
| 800 | struct nf_conn_help *help = nfct_help(ct); |
| 801 | struct nf_conntrack_expect *exp; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 802 | struct hlist_node *next; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 803 | int found = 0; |
| 804 | |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 805 | spin_lock_bh(&nf_conntrack_expect_lock); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 806 | hlist_for_each_entry_safe(exp, next, &help->expectations, lnode) { |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 807 | if (exp->class != SIP_EXPECT_SIGNALLING || |
| 808 | !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) || |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 809 | exp->tuple.dst.protonum != proto || |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 810 | exp->tuple.dst.u.udp.port != port) |
| 811 | continue; |
| 812 | if (!del_timer(&exp->timeout)) |
| 813 | continue; |
| 814 | exp->flags &= ~NF_CT_EXPECT_INACTIVE; |
| 815 | exp->timeout.expires = jiffies + expires * HZ; |
| 816 | add_timer(&exp->timeout); |
| 817 | found = 1; |
| 818 | break; |
| 819 | } |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 820 | spin_unlock_bh(&nf_conntrack_expect_lock); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 821 | return found; |
| 822 | } |
| 823 | |
| 824 | static void flush_expectations(struct nf_conn *ct, bool media) |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 825 | { |
| 826 | struct nf_conn_help *help = nfct_help(ct); |
| 827 | struct nf_conntrack_expect *exp; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 828 | struct hlist_node *next; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 829 | |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 830 | spin_lock_bh(&nf_conntrack_expect_lock); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 831 | hlist_for_each_entry_safe(exp, next, &help->expectations, lnode) { |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 832 | if ((exp->class != SIP_EXPECT_SIGNALLING) ^ media) |
| 833 | continue; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 834 | if (!del_timer(&exp->timeout)) |
| 835 | continue; |
| 836 | nf_ct_unlink_expect(exp); |
| 837 | nf_ct_expect_put(exp); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 838 | if (!media) |
| 839 | break; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 840 | } |
Jesper Dangaard Brouer | ca7433d | 2014-03-03 14:46:01 +0100 | [diff] [blame] | 841 | spin_unlock_bh(&nf_conntrack_expect_lock); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 842 | } |
| 843 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 844 | static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff, |
| 845 | unsigned int dataoff, |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 846 | const char **dptr, unsigned int *datalen, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 847 | union nf_inet_addr *daddr, __be16 port, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 848 | enum sip_expectation_classes class, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 849 | unsigned int mediaoff, unsigned int medialen) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 850 | { |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 851 | struct nf_conntrack_expect *exp, *rtp_exp, *rtcp_exp; |
Patrick McHardy | 212440a | 2008-03-25 20:17:13 -0700 | [diff] [blame] | 852 | enum ip_conntrack_info ctinfo; |
| 853 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Alexey Dobriyan | a5c3a80 | 2008-10-08 11:35:09 +0200 | [diff] [blame] | 854 | struct net *net = nf_ct_net(ct); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 855 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 856 | union nf_inet_addr *saddr; |
| 857 | struct nf_conntrack_tuple tuple; |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 858 | int direct_rtp = 0, skip_expect = 0, ret = NF_DROP; |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 859 | u_int16_t base_port; |
| 860 | __be16 rtp_port, rtcp_port; |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 861 | const struct nf_nat_sip_hooks *hooks; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 862 | |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 863 | saddr = NULL; |
| 864 | if (sip_direct_media) { |
| 865 | if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3)) |
| 866 | return NF_ACCEPT; |
| 867 | saddr = &ct->tuplehash[!dir].tuple.src.u3; |
| 868 | } |
| 869 | |
| 870 | /* We need to check whether the registration exists before attempting |
| 871 | * to register it since we can see the same media description multiple |
| 872 | * times on different connections in case multiple endpoints receive |
| 873 | * the same call. |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 874 | * |
| 875 | * RTP optimization: if we find a matching media channel expectation |
| 876 | * and both the expectation and this connection are SNATed, we assume |
| 877 | * both sides can reach each other directly and use the final |
| 878 | * destination address from the expectation. We still need to keep |
| 879 | * the NATed expectations for media that might arrive from the |
| 880 | * outside, and additionally need to expect the direct RTP stream |
| 881 | * in case it passes through us even without NAT. |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 882 | */ |
| 883 | memset(&tuple, 0, sizeof(tuple)); |
| 884 | if (saddr) |
| 885 | tuple.src.u3 = *saddr; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 886 | tuple.src.l3num = nf_ct_l3num(ct); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 887 | tuple.dst.protonum = IPPROTO_UDP; |
| 888 | tuple.dst.u3 = *daddr; |
| 889 | tuple.dst.u.udp.port = port; |
| 890 | |
| 891 | rcu_read_lock(); |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 892 | do { |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 893 | exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 894 | |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 895 | if (!exp || exp->master == ct || |
| 896 | nfct_help(exp->master)->helper != nfct_help(ct)->helper || |
| 897 | exp->class != class) |
| 898 | break; |
Patrick McHardy | e1f9a46 | 2008-04-19 17:53:52 -0700 | [diff] [blame] | 899 | #ifdef CONFIG_NF_NAT_NEEDED |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 900 | if (!direct_rtp && |
| 901 | (!nf_inet_addr_cmp(&exp->saved_addr, &exp->tuple.dst.u3) || |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 902 | exp->saved_proto.udp.port != exp->tuple.dst.u.udp.port) && |
| 903 | ct->status & IPS_NAT_MASK) { |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 904 | *daddr = exp->saved_addr; |
| 905 | tuple.dst.u3 = exp->saved_addr; |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 906 | tuple.dst.u.udp.port = exp->saved_proto.udp.port; |
| 907 | direct_rtp = 1; |
| 908 | } else |
Patrick McHardy | e1f9a46 | 2008-04-19 17:53:52 -0700 | [diff] [blame] | 909 | #endif |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 910 | skip_expect = 1; |
| 911 | } while (!skip_expect); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 912 | |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 913 | base_port = ntohs(tuple.dst.u.udp.port) & ~1; |
| 914 | rtp_port = htons(base_port); |
| 915 | rtcp_port = htons(base_port + 1); |
| 916 | |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 917 | if (direct_rtp) { |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 918 | hooks = rcu_dereference(nf_nat_sip_hooks); |
| 919 | if (hooks && |
| 920 | !hooks->sdp_port(skb, protoff, dataoff, dptr, datalen, |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 921 | mediaoff, medialen, ntohs(rtp_port))) |
| 922 | goto err1; |
| 923 | } |
| 924 | |
holger@eitzenberger.org | b21613a | 2013-09-20 22:43:04 +0200 | [diff] [blame] | 925 | if (skip_expect) { |
| 926 | rcu_read_unlock(); |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 927 | return NF_ACCEPT; |
holger@eitzenberger.org | b21613a | 2013-09-20 22:43:04 +0200 | [diff] [blame] | 928 | } |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 929 | |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 930 | rtp_exp = nf_ct_expect_alloc(ct); |
| 931 | if (rtp_exp == NULL) |
| 932 | goto err1; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 933 | nf_ct_expect_init(rtp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 934 | IPPROTO_UDP, NULL, &rtp_port); |
| 935 | |
| 936 | rtcp_exp = nf_ct_expect_alloc(ct); |
| 937 | if (rtcp_exp == NULL) |
| 938 | goto err2; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 939 | nf_ct_expect_init(rtcp_exp, class, nf_ct_l3num(ct), saddr, daddr, |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 940 | IPPROTO_UDP, NULL, &rtcp_port); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 941 | |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 942 | hooks = rcu_dereference(nf_nat_sip_hooks); |
| 943 | if (hooks && ct->status & IPS_NAT_MASK && !direct_rtp) |
| 944 | ret = hooks->sdp_media(skb, protoff, dataoff, dptr, |
| 945 | datalen, rtp_exp, rtcp_exp, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 946 | mediaoff, medialen, daddr); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 947 | else { |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 948 | if (nf_ct_expect_related(rtp_exp) == 0) { |
| 949 | if (nf_ct_expect_related(rtcp_exp) != 0) |
| 950 | nf_ct_unexpect_related(rtp_exp); |
| 951 | else |
| 952 | ret = NF_ACCEPT; |
| 953 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 954 | } |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 955 | nf_ct_expect_put(rtcp_exp); |
| 956 | err2: |
| 957 | nf_ct_expect_put(rtp_exp); |
| 958 | err1: |
holger@eitzenberger.org | b21613a | 2013-09-20 22:43:04 +0200 | [diff] [blame] | 959 | rcu_read_unlock(); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 960 | return ret; |
| 961 | } |
| 962 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 963 | static const struct sdp_media_type sdp_media_types[] = { |
| 964 | SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO), |
| 965 | SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO), |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 966 | SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE), |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 967 | }; |
| 968 | |
| 969 | static const struct sdp_media_type *sdp_media_type(const char *dptr, |
| 970 | unsigned int matchoff, |
| 971 | unsigned int matchlen) |
| 972 | { |
| 973 | const struct sdp_media_type *t; |
| 974 | unsigned int i; |
| 975 | |
| 976 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); i++) { |
| 977 | t = &sdp_media_types[i]; |
| 978 | if (matchlen < t->len || |
| 979 | strncmp(dptr + matchoff, t->name, t->len)) |
| 980 | continue; |
| 981 | return t; |
| 982 | } |
| 983 | return NULL; |
| 984 | } |
| 985 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 986 | static int process_sdp(struct sk_buff *skb, unsigned int protoff, |
| 987 | unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 988 | const char **dptr, unsigned int *datalen, |
| 989 | unsigned int cseq) |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 990 | { |
| 991 | enum ip_conntrack_info ctinfo; |
| 992 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 993 | unsigned int matchoff, matchlen; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 994 | unsigned int mediaoff, medialen; |
| 995 | unsigned int sdpoff; |
| 996 | unsigned int caddr_len, maddr_len; |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 997 | unsigned int i; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 998 | union nf_inet_addr caddr, maddr, rtp_addr; |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 999 | const struct nf_nat_sip_hooks *hooks; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1000 | unsigned int port; |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1001 | const struct sdp_media_type *t; |
| 1002 | int ret = NF_ACCEPT; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1003 | |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1004 | hooks = rcu_dereference(nf_nat_sip_hooks); |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1005 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1006 | /* Find beginning of session description */ |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1007 | if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1008 | SDP_HDR_VERSION, SDP_HDR_UNSPEC, |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1009 | &matchoff, &matchlen) <= 0) |
| 1010 | return NF_ACCEPT; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1011 | sdpoff = matchoff; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1012 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1013 | /* The connection information is contained in the session description |
| 1014 | * and/or once per media description. The first media description marks |
| 1015 | * the end of the session description. */ |
| 1016 | caddr_len = 0; |
| 1017 | if (ct_sip_parse_sdp_addr(ct, *dptr, sdpoff, *datalen, |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 1018 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1019 | &matchoff, &matchlen, &caddr) > 0) |
| 1020 | caddr_len = matchlen; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1021 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1022 | mediaoff = sdpoff; |
| 1023 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); ) { |
| 1024 | if (ct_sip_get_sdp_header(ct, *dptr, mediaoff, *datalen, |
| 1025 | SDP_HDR_MEDIA, SDP_HDR_UNSPEC, |
| 1026 | &mediaoff, &medialen) <= 0) |
| 1027 | break; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1028 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1029 | /* Get media type and port number. A media port value of zero |
| 1030 | * indicates an inactive stream. */ |
| 1031 | t = sdp_media_type(*dptr, mediaoff, medialen); |
| 1032 | if (!t) { |
| 1033 | mediaoff += medialen; |
| 1034 | continue; |
| 1035 | } |
| 1036 | mediaoff += t->len; |
| 1037 | medialen -= t->len; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1038 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1039 | port = simple_strtoul(*dptr + mediaoff, NULL, 10); |
| 1040 | if (port == 0) |
| 1041 | continue; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1042 | if (port < 1024 || port > 65535) { |
| 1043 | nf_ct_helper_log(skb, ct, "wrong port %u", port); |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1044 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1045 | } |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1046 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1047 | /* The media description overrides the session description. */ |
| 1048 | maddr_len = 0; |
| 1049 | if (ct_sip_parse_sdp_addr(ct, *dptr, mediaoff, *datalen, |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 1050 | SDP_HDR_CONNECTION, SDP_HDR_MEDIA, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1051 | &matchoff, &matchlen, &maddr) > 0) { |
| 1052 | maddr_len = matchlen; |
| 1053 | memcpy(&rtp_addr, &maddr, sizeof(rtp_addr)); |
| 1054 | } else if (caddr_len) |
| 1055 | memcpy(&rtp_addr, &caddr, sizeof(rtp_addr)); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1056 | else { |
| 1057 | nf_ct_helper_log(skb, ct, "cannot parse SDP message"); |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1058 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1059 | } |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1060 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1061 | ret = set_expected_rtp_rtcp(skb, protoff, dataoff, |
| 1062 | dptr, datalen, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1063 | &rtp_addr, htons(port), t->class, |
| 1064 | mediaoff, medialen); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1065 | if (ret != NF_ACCEPT) { |
| 1066 | nf_ct_helper_log(skb, ct, |
| 1067 | "cannot add expectation for voice"); |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1068 | return ret; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1069 | } |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1070 | |
| 1071 | /* Update media connection address if present */ |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1072 | if (maddr_len && hooks && ct->status & IPS_NAT_MASK) { |
| 1073 | ret = hooks->sdp_addr(skb, protoff, dataoff, |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 1074 | dptr, datalen, mediaoff, |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1075 | SDP_HDR_CONNECTION, |
| 1076 | SDP_HDR_MEDIA, |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1077 | &rtp_addr); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1078 | if (ret != NF_ACCEPT) { |
| 1079 | nf_ct_helper_log(skb, ct, "cannot mangle SDP"); |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1080 | return ret; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1081 | } |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1082 | } |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1083 | i++; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1084 | } |
| 1085 | |
| 1086 | /* Update session connection and owner addresses */ |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1087 | hooks = rcu_dereference(nf_nat_sip_hooks); |
| 1088 | if (hooks && ct->status & IPS_NAT_MASK) |
| 1089 | ret = hooks->sdp_session(skb, protoff, dataoff, |
| 1090 | dptr, datalen, sdpoff, |
| 1091 | &rtp_addr); |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1092 | |
| 1093 | return ret; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1094 | } |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1095 | static int process_invite_response(struct sk_buff *skb, unsigned int protoff, |
| 1096 | unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1097 | const char **dptr, unsigned int *datalen, |
| 1098 | unsigned int cseq, unsigned int code) |
| 1099 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1100 | enum ip_conntrack_info ctinfo; |
| 1101 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1102 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1103 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1104 | if ((code >= 100 && code <= 199) || |
| 1105 | (code >= 200 && code <= 299)) |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1106 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1107 | else if (ct_sip_info->invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1108 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1109 | return NF_ACCEPT; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1110 | } |
| 1111 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1112 | static int process_update_response(struct sk_buff *skb, unsigned int protoff, |
| 1113 | unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1114 | const char **dptr, unsigned int *datalen, |
| 1115 | unsigned int cseq, unsigned int code) |
| 1116 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1117 | enum ip_conntrack_info ctinfo; |
| 1118 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1119 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1120 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1121 | if ((code >= 100 && code <= 199) || |
| 1122 | (code >= 200 && code <= 299)) |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1123 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1124 | else if (ct_sip_info->invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1125 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1126 | return NF_ACCEPT; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1127 | } |
| 1128 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1129 | static int process_prack_response(struct sk_buff *skb, unsigned int protoff, |
| 1130 | unsigned int dataoff, |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1131 | const char **dptr, unsigned int *datalen, |
| 1132 | unsigned int cseq, unsigned int code) |
| 1133 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1134 | enum ip_conntrack_info ctinfo; |
| 1135 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1136 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1137 | |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1138 | if ((code >= 100 && code <= 199) || |
| 1139 | (code >= 200 && code <= 299)) |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1140 | return process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1141 | else if (ct_sip_info->invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1142 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1143 | return NF_ACCEPT; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1144 | } |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1145 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1146 | static int process_invite_request(struct sk_buff *skb, unsigned int protoff, |
| 1147 | unsigned int dataoff, |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1148 | const char **dptr, unsigned int *datalen, |
| 1149 | unsigned int cseq) |
| 1150 | { |
| 1151 | enum ip_conntrack_info ctinfo; |
| 1152 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1153 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1154 | unsigned int ret; |
| 1155 | |
| 1156 | flush_expectations(ct, true); |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1157 | ret = process_sdp(skb, protoff, dataoff, dptr, datalen, cseq); |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1158 | if (ret == NF_ACCEPT) |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1159 | ct_sip_info->invite_cseq = cseq; |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1160 | return ret; |
| 1161 | } |
| 1162 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1163 | static int process_bye_request(struct sk_buff *skb, unsigned int protoff, |
| 1164 | unsigned int dataoff, |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1165 | const char **dptr, unsigned int *datalen, |
| 1166 | unsigned int cseq) |
| 1167 | { |
| 1168 | enum ip_conntrack_info ctinfo; |
| 1169 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1170 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1171 | flush_expectations(ct, true); |
| 1172 | return NF_ACCEPT; |
| 1173 | } |
| 1174 | |
| 1175 | /* Parse a REGISTER request and create a permanent expectation for incoming |
| 1176 | * signalling connections. The expectation is marked inactive and is activated |
| 1177 | * when receiving a response indicating success from the registrar. |
| 1178 | */ |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1179 | static int process_register_request(struct sk_buff *skb, unsigned int protoff, |
| 1180 | unsigned int dataoff, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1181 | const char **dptr, unsigned int *datalen, |
| 1182 | unsigned int cseq) |
| 1183 | { |
| 1184 | enum ip_conntrack_info ctinfo; |
| 1185 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1186 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1187 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1188 | unsigned int matchoff, matchlen; |
| 1189 | struct nf_conntrack_expect *exp; |
| 1190 | union nf_inet_addr *saddr, daddr; |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1191 | const struct nf_nat_sip_hooks *hooks; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1192 | __be16 port; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1193 | u8 proto; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1194 | unsigned int expires = 0; |
| 1195 | int ret; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1196 | |
| 1197 | /* Expected connections can not register again. */ |
| 1198 | if (ct->status & IPS_EXPECTED) |
| 1199 | return NF_ACCEPT; |
| 1200 | |
| 1201 | /* We must check the expiration time: a value of zero signals the |
| 1202 | * registrar to release the binding. We'll remove our expectation |
| 1203 | * when receiving the new bindings in the response, but we don't |
| 1204 | * want to create new ones. |
| 1205 | * |
| 1206 | * The expiration time may be contained in Expires: header, the |
| 1207 | * Contact: header parameters or the URI parameters. |
| 1208 | */ |
| 1209 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, |
| 1210 | &matchoff, &matchlen) > 0) |
| 1211 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1212 | |
| 1213 | ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, |
| 1214 | SIP_HDR_CONTACT, NULL, |
| 1215 | &matchoff, &matchlen, &daddr, &port); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1216 | if (ret < 0) { |
| 1217 | nf_ct_helper_log(skb, ct, "cannot parse contact"); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1218 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1219 | } else if (ret == 0) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1220 | return NF_ACCEPT; |
| 1221 | |
| 1222 | /* We don't support third-party registrations */ |
| 1223 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr)) |
| 1224 | return NF_ACCEPT; |
| 1225 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1226 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, *datalen, |
| 1227 | &proto) == 0) |
| 1228 | return NF_ACCEPT; |
| 1229 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1230 | if (ct_sip_parse_numerical_param(ct, *dptr, |
| 1231 | matchoff + matchlen, *datalen, |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1232 | "expires=", NULL, NULL, &expires) < 0) { |
| 1233 | nf_ct_helper_log(skb, ct, "cannot parse expires"); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1234 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1235 | } |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1236 | |
| 1237 | if (expires == 0) { |
| 1238 | ret = NF_ACCEPT; |
| 1239 | goto store_cseq; |
| 1240 | } |
| 1241 | |
| 1242 | exp = nf_ct_expect_alloc(ct); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1243 | if (!exp) { |
| 1244 | nf_ct_helper_log(skb, ct, "cannot alloc expectation"); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1245 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1246 | } |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1247 | |
| 1248 | saddr = NULL; |
| 1249 | if (sip_direct_signalling) |
| 1250 | saddr = &ct->tuplehash[!dir].tuple.src.u3; |
| 1251 | |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 1252 | nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct), |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1253 | saddr, &daddr, proto, NULL, &port); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1254 | exp->timeout.expires = sip_timeout * HZ; |
| 1255 | exp->helper = nfct_help(ct)->helper; |
| 1256 | exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE; |
| 1257 | |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1258 | hooks = rcu_dereference(nf_nat_sip_hooks); |
| 1259 | if (hooks && ct->status & IPS_NAT_MASK) |
| 1260 | ret = hooks->expect(skb, protoff, dataoff, dptr, datalen, |
| 1261 | exp, matchoff, matchlen); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1262 | else { |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1263 | if (nf_ct_expect_related(exp) != 0) { |
| 1264 | nf_ct_helper_log(skb, ct, "cannot add expectation"); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1265 | ret = NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1266 | } else |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1267 | ret = NF_ACCEPT; |
| 1268 | } |
| 1269 | nf_ct_expect_put(exp); |
| 1270 | |
| 1271 | store_cseq: |
| 1272 | if (ret == NF_ACCEPT) |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1273 | ct_sip_info->register_cseq = cseq; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1274 | return ret; |
| 1275 | } |
| 1276 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1277 | static int process_register_response(struct sk_buff *skb, unsigned int protoff, |
| 1278 | unsigned int dataoff, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1279 | const char **dptr, unsigned int *datalen, |
| 1280 | unsigned int cseq, unsigned int code) |
| 1281 | { |
| 1282 | enum ip_conntrack_info ctinfo; |
| 1283 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1284 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1285 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 1286 | union nf_inet_addr addr; |
| 1287 | __be16 port; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1288 | u8 proto; |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1289 | unsigned int matchoff, matchlen, coff = 0; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1290 | unsigned int expires = 0; |
| 1291 | int in_contact = 0, ret; |
| 1292 | |
| 1293 | /* According to RFC 3261, "UAs MUST NOT send a new registration until |
| 1294 | * they have received a final response from the registrar for the |
| 1295 | * previous one or the previous REGISTER request has timed out". |
| 1296 | * |
| 1297 | * However, some servers fail to detect retransmissions and send late |
| 1298 | * responses, so we store the sequence number of the last valid |
| 1299 | * request and compare it here. |
| 1300 | */ |
Pablo Neira Ayuso | 1afc567 | 2012-06-07 12:11:50 +0200 | [diff] [blame] | 1301 | if (ct_sip_info->register_cseq != cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1302 | return NF_ACCEPT; |
| 1303 | |
| 1304 | if (code >= 100 && code <= 199) |
| 1305 | return NF_ACCEPT; |
| 1306 | if (code < 200 || code > 299) |
| 1307 | goto flush; |
| 1308 | |
| 1309 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, |
| 1310 | &matchoff, &matchlen) > 0) |
| 1311 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1312 | |
| 1313 | while (1) { |
| 1314 | unsigned int c_expires = expires; |
| 1315 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1316 | ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1317 | SIP_HDR_CONTACT, &in_contact, |
| 1318 | &matchoff, &matchlen, |
| 1319 | &addr, &port); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1320 | if (ret < 0) { |
| 1321 | nf_ct_helper_log(skb, ct, "cannot parse contact"); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1322 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1323 | } else if (ret == 0) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1324 | break; |
| 1325 | |
| 1326 | /* We don't support third-party registrations */ |
| 1327 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr)) |
| 1328 | continue; |
| 1329 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1330 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, |
| 1331 | *datalen, &proto) == 0) |
| 1332 | continue; |
| 1333 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1334 | ret = ct_sip_parse_numerical_param(ct, *dptr, |
| 1335 | matchoff + matchlen, |
| 1336 | *datalen, "expires=", |
| 1337 | NULL, NULL, &c_expires); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1338 | if (ret < 0) { |
| 1339 | nf_ct_helper_log(skb, ct, "cannot parse expires"); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1340 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1341 | } |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1342 | if (c_expires == 0) |
| 1343 | break; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1344 | if (refresh_signalling_expectation(ct, &addr, proto, port, |
| 1345 | c_expires)) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1346 | return NF_ACCEPT; |
| 1347 | } |
| 1348 | |
| 1349 | flush: |
| 1350 | flush_expectations(ct, false); |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1351 | return NF_ACCEPT; |
| 1352 | } |
| 1353 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1354 | static const struct sip_handler sip_handlers[] = { |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1355 | SIP_HANDLER("INVITE", process_invite_request, process_invite_response), |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1356 | SIP_HANDLER("UPDATE", process_sdp, process_update_response), |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1357 | SIP_HANDLER("ACK", process_sdp, NULL), |
| 1358 | SIP_HANDLER("PRACK", process_sdp, process_prack_response), |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1359 | SIP_HANDLER("BYE", process_bye_request, NULL), |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1360 | SIP_HANDLER("REGISTER", process_register_request, process_register_response), |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1361 | }; |
| 1362 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1363 | static int process_sip_response(struct sk_buff *skb, unsigned int protoff, |
| 1364 | unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1365 | const char **dptr, unsigned int *datalen) |
| 1366 | { |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1367 | enum ip_conntrack_info ctinfo; |
| 1368 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1369 | unsigned int matchoff, matchlen, matchend; |
| 1370 | unsigned int code, cseq, i; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1371 | |
| 1372 | if (*datalen < strlen("SIP/2.0 200")) |
| 1373 | return NF_ACCEPT; |
| 1374 | code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1375 | if (!code) { |
| 1376 | nf_ct_helper_log(skb, ct, "cannot get code"); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1377 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1378 | } |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1379 | |
| 1380 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1381 | &matchoff, &matchlen) <= 0) { |
| 1382 | nf_ct_helper_log(skb, ct, "cannot parse cseq"); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1383 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1384 | } |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1385 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
Christophe Leroy | 0d35d081 | 2016-08-03 12:41:40 +0200 | [diff] [blame] | 1386 | if (!cseq && *(*dptr + matchoff) != '0') { |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1387 | nf_ct_helper_log(skb, ct, "cannot get cseq"); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1388 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1389 | } |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1390 | matchend = matchoff + matchlen + 1; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1391 | |
| 1392 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { |
Alexey Dobriyan | 66bf791 | 2008-09-07 18:19:25 -0700 | [diff] [blame] | 1393 | const struct sip_handler *handler; |
| 1394 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1395 | handler = &sip_handlers[i]; |
| 1396 | if (handler->response == NULL) |
| 1397 | continue; |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1398 | if (*datalen < matchend + handler->len || |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 1399 | strncasecmp(*dptr + matchend, handler->method, handler->len)) |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1400 | continue; |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1401 | return handler->response(skb, protoff, dataoff, dptr, datalen, |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1402 | cseq, code); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1403 | } |
| 1404 | return NF_ACCEPT; |
| 1405 | } |
| 1406 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1407 | static int process_sip_request(struct sk_buff *skb, unsigned int protoff, |
| 1408 | unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1409 | const char **dptr, unsigned int *datalen) |
| 1410 | { |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1411 | enum ip_conntrack_info ctinfo; |
| 1412 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Kevin Cernekee | 7266507 | 2012-12-17 18:33:58 +0000 | [diff] [blame] | 1413 | struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct); |
| 1414 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1415 | unsigned int matchoff, matchlen; |
| 1416 | unsigned int cseq, i; |
Kevin Cernekee | 7266507 | 2012-12-17 18:33:58 +0000 | [diff] [blame] | 1417 | union nf_inet_addr addr; |
| 1418 | __be16 port; |
| 1419 | |
| 1420 | /* Many Cisco IP phones use a high source port for SIP requests, but |
| 1421 | * listen for the response on port 5060. If we are the local |
| 1422 | * router for one of these phones, save the port number from the |
| 1423 | * Via: header so that nf_nat_sip can redirect the responses to |
| 1424 | * the correct port. |
| 1425 | */ |
| 1426 | if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, |
| 1427 | SIP_HDR_VIA_UDP, NULL, &matchoff, |
| 1428 | &matchlen, &addr, &port) > 0 && |
| 1429 | port != ct->tuplehash[dir].tuple.src.u.udp.port && |
| 1430 | nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3)) |
| 1431 | ct_sip_info->forced_dport = port; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1432 | |
| 1433 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { |
Alexey Dobriyan | 66bf791 | 2008-09-07 18:19:25 -0700 | [diff] [blame] | 1434 | const struct sip_handler *handler; |
| 1435 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1436 | handler = &sip_handlers[i]; |
| 1437 | if (handler->request == NULL) |
| 1438 | continue; |
Ulrich Weber | 444f901 | 2016-10-24 18:07:23 +0200 | [diff] [blame] | 1439 | if (*datalen < handler->len + 2 || |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 1440 | strncasecmp(*dptr, handler->method, handler->len)) |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1441 | continue; |
Ulrich Weber | 444f901 | 2016-10-24 18:07:23 +0200 | [diff] [blame] | 1442 | if ((*dptr)[handler->len] != ' ' || |
| 1443 | !isalpha((*dptr)[handler->len+1])) |
| 1444 | continue; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1445 | |
| 1446 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1447 | &matchoff, &matchlen) <= 0) { |
| 1448 | nf_ct_helper_log(skb, ct, "cannot parse cseq"); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1449 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1450 | } |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1451 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
Christophe Leroy | 0d35d081 | 2016-08-03 12:41:40 +0200 | [diff] [blame] | 1452 | if (!cseq && *(*dptr + matchoff) != '0') { |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1453 | nf_ct_helper_log(skb, ct, "cannot get cseq"); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1454 | return NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1455 | } |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1456 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1457 | return handler->request(skb, protoff, dataoff, dptr, datalen, |
| 1458 | cseq); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1459 | } |
| 1460 | return NF_ACCEPT; |
| 1461 | } |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1462 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1463 | static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct, |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1464 | unsigned int protoff, unsigned int dataoff, |
| 1465 | const char **dptr, unsigned int *datalen) |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1466 | { |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1467 | const struct nf_nat_sip_hooks *hooks; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1468 | int ret; |
| 1469 | |
Rasmus Villemoes | 1808274 | 2014-10-13 15:54:31 -0700 | [diff] [blame] | 1470 | if (strncasecmp(*dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0) |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1471 | ret = process_sip_request(skb, protoff, dataoff, dptr, datalen); |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1472 | else |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1473 | ret = process_sip_response(skb, protoff, dataoff, dptr, datalen); |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1474 | |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 1475 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1476 | hooks = rcu_dereference(nf_nat_sip_hooks); |
| 1477 | if (hooks && !hooks->msg(skb, protoff, dataoff, |
| 1478 | dptr, datalen)) { |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1479 | nf_ct_helper_log(skb, ct, "cannot NAT SIP message"); |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1480 | ret = NF_DROP; |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1481 | } |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1482 | } |
| 1483 | |
| 1484 | return ret; |
| 1485 | } |
| 1486 | |
| 1487 | static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, |
| 1488 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
| 1489 | { |
| 1490 | struct tcphdr *th, _tcph; |
| 1491 | unsigned int dataoff, datalen; |
| 1492 | unsigned int matchoff, matchlen, clen; |
| 1493 | unsigned int msglen, origlen; |
| 1494 | const char *dptr, *end; |
| 1495 | s16 diff, tdiff = 0; |
Simon Horman | 7874896 | 2010-09-21 21:17:30 +0000 | [diff] [blame] | 1496 | int ret = NF_ACCEPT; |
Patrick McHardy | e6e4d9e | 2011-05-16 14:45:39 +0200 | [diff] [blame] | 1497 | bool term; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1498 | |
| 1499 | if (ctinfo != IP_CT_ESTABLISHED && |
Eric Dumazet | fb04883 | 2011-05-19 15:44:27 +0200 | [diff] [blame] | 1500 | ctinfo != IP_CT_ESTABLISHED_REPLY) |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1501 | return NF_ACCEPT; |
| 1502 | |
| 1503 | /* No Data ? */ |
| 1504 | th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
| 1505 | if (th == NULL) |
| 1506 | return NF_ACCEPT; |
| 1507 | dataoff = protoff + th->doff * 4; |
| 1508 | if (dataoff >= skb->len) |
| 1509 | return NF_ACCEPT; |
| 1510 | |
| 1511 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
| 1512 | |
Patrick McHardy | a1d7c1b | 2010-05-14 21:18:17 +0200 | [diff] [blame] | 1513 | if (unlikely(skb_linearize(skb))) |
| 1514 | return NF_DROP; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1515 | |
| 1516 | dptr = skb->data + dataoff; |
| 1517 | datalen = skb->len - dataoff; |
| 1518 | if (datalen < strlen("SIP/2.0 200")) |
| 1519 | return NF_ACCEPT; |
| 1520 | |
| 1521 | while (1) { |
| 1522 | if (ct_sip_get_header(ct, dptr, 0, datalen, |
| 1523 | SIP_HDR_CONTENT_LENGTH, |
| 1524 | &matchoff, &matchlen) <= 0) |
| 1525 | break; |
| 1526 | |
| 1527 | clen = simple_strtoul(dptr + matchoff, (char **)&end, 10); |
| 1528 | if (dptr + matchoff == end) |
| 1529 | break; |
| 1530 | |
Patrick McHardy | e6e4d9e | 2011-05-16 14:45:39 +0200 | [diff] [blame] | 1531 | term = false; |
| 1532 | for (; end + strlen("\r\n\r\n") <= dptr + datalen; end++) { |
| 1533 | if (end[0] == '\r' && end[1] == '\n' && |
| 1534 | end[2] == '\r' && end[3] == '\n') { |
| 1535 | term = true; |
| 1536 | break; |
| 1537 | } |
| 1538 | } |
| 1539 | if (!term) |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1540 | break; |
| 1541 | end += strlen("\r\n\r\n") + clen; |
| 1542 | |
| 1543 | msglen = origlen = end - dptr; |
Patrick McHardy | 3a7b21e | 2013-04-05 08:13:30 +0000 | [diff] [blame] | 1544 | if (msglen > datalen) |
| 1545 | return NF_ACCEPT; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1546 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1547 | ret = process_sip_msg(skb, ct, protoff, dataoff, |
| 1548 | &dptr, &msglen); |
Pablo Neira Ayuso | b20ab9cc | 2013-02-10 18:56:56 +0100 | [diff] [blame] | 1549 | /* process_sip_* functions report why this packet is dropped */ |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1550 | if (ret != NF_ACCEPT) |
| 1551 | break; |
| 1552 | diff = msglen - origlen; |
| 1553 | tdiff += diff; |
| 1554 | |
| 1555 | dataoff += msglen; |
| 1556 | dptr += msglen; |
| 1557 | datalen = datalen + diff - msglen; |
| 1558 | } |
| 1559 | |
Patrick McHardy | 9a66482 | 2012-08-26 19:14:25 +0200 | [diff] [blame] | 1560 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
holger@eitzenberger.org | 180cf72 | 2013-09-30 17:07:28 +0200 | [diff] [blame] | 1561 | const struct nf_nat_sip_hooks *hooks; |
| 1562 | |
| 1563 | hooks = rcu_dereference(nf_nat_sip_hooks); |
| 1564 | if (hooks) |
| 1565 | hooks->seq_adjust(skb, protoff, tdiff); |
Patrick McHardy | 48f8ac2 | 2010-02-11 12:29:38 +0100 | [diff] [blame] | 1566 | } |
| 1567 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1568 | return ret; |
| 1569 | } |
| 1570 | |
| 1571 | static int sip_help_udp(struct sk_buff *skb, unsigned int protoff, |
| 1572 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1573 | { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1574 | unsigned int dataoff, datalen; |
| 1575 | const char *dptr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1576 | |
| 1577 | /* No Data ? */ |
| 1578 | dataoff = protoff + sizeof(struct udphdr); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1579 | if (dataoff >= skb->len) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1580 | return NF_ACCEPT; |
| 1581 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1582 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1583 | |
Patrick McHardy | a1d7c1b | 2010-05-14 21:18:17 +0200 | [diff] [blame] | 1584 | if (unlikely(skb_linearize(skb))) |
| 1585 | return NF_DROP; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1586 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1587 | dptr = skb->data + dataoff; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1588 | datalen = skb->len - dataoff; |
Patrick McHardy | 779382e | 2008-03-25 20:17:36 -0700 | [diff] [blame] | 1589 | if (datalen < strlen("SIP/2.0 200")) |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1590 | return NF_ACCEPT; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1591 | |
Patrick McHardy | 051966c | 2012-08-26 19:14:04 +0200 | [diff] [blame] | 1592 | return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1593 | } |
| 1594 | |
Gao Feng | 82de0be | 2016-07-18 11:39:23 +0800 | [diff] [blame] | 1595 | static struct nf_conntrack_helper sip[MAX_PORTS * 4] __read_mostly; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1596 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1597 | static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { |
| 1598 | [SIP_EXPECT_SIGNALLING] = { |
Patrick McHardy | b87921b | 2010-02-11 12:22:48 +0100 | [diff] [blame] | 1599 | .name = "signalling", |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1600 | .max_expected = 1, |
| 1601 | .timeout = 3 * 60, |
| 1602 | }, |
| 1603 | [SIP_EXPECT_AUDIO] = { |
Patrick McHardy | b87921b | 2010-02-11 12:22:48 +0100 | [diff] [blame] | 1604 | .name = "audio", |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 1605 | .max_expected = 2 * IP_CT_DIR_MAX, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1606 | .timeout = 3 * 60, |
| 1607 | }, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1608 | [SIP_EXPECT_VIDEO] = { |
Patrick McHardy | b87921b | 2010-02-11 12:22:48 +0100 | [diff] [blame] | 1609 | .name = "video", |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1610 | .max_expected = 2 * IP_CT_DIR_MAX, |
| 1611 | .timeout = 3 * 60, |
| 1612 | }, |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1613 | [SIP_EXPECT_IMAGE] = { |
| 1614 | .name = "image", |
| 1615 | .max_expected = IP_CT_DIR_MAX, |
| 1616 | .timeout = 3 * 60, |
| 1617 | }, |
Patrick McHardy | 6002f266 | 2008-03-25 20:09:15 -0700 | [diff] [blame] | 1618 | }; |
| 1619 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1620 | static void nf_conntrack_sip_fini(void) |
| 1621 | { |
Gao Feng | 82de0be | 2016-07-18 11:39:23 +0800 | [diff] [blame] | 1622 | nf_conntrack_helpers_unregister(sip, ports_c * 4); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1623 | } |
| 1624 | |
| 1625 | static int __init nf_conntrack_sip_init(void) |
| 1626 | { |
Gao Feng | 82de0be | 2016-07-18 11:39:23 +0800 | [diff] [blame] | 1627 | int i, ret; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1628 | |
| 1629 | if (ports_c == 0) |
| 1630 | ports[ports_c++] = SIP_PORT; |
| 1631 | |
| 1632 | for (i = 0; i < ports_c; i++) { |
Gao Feng | 82de0be | 2016-07-18 11:39:23 +0800 | [diff] [blame] | 1633 | nf_ct_helper_init(&sip[4 * i], AF_INET, IPPROTO_UDP, "sip", |
| 1634 | SIP_PORT, ports[i], i, sip_exp_policy, |
| 1635 | SIP_EXPECT_MAX, |
| 1636 | sizeof(struct nf_ct_sip_master), sip_help_udp, |
| 1637 | NULL, THIS_MODULE); |
| 1638 | nf_ct_helper_init(&sip[4 * i + 1], AF_INET, IPPROTO_TCP, "sip", |
| 1639 | SIP_PORT, ports[i], i, sip_exp_policy, |
| 1640 | SIP_EXPECT_MAX, |
| 1641 | sizeof(struct nf_ct_sip_master), sip_help_tcp, |
| 1642 | NULL, THIS_MODULE); |
| 1643 | nf_ct_helper_init(&sip[4 * i + 2], AF_INET6, IPPROTO_UDP, "sip", |
| 1644 | SIP_PORT, ports[i], i, sip_exp_policy, |
| 1645 | SIP_EXPECT_MAX, |
| 1646 | sizeof(struct nf_ct_sip_master), sip_help_udp, |
| 1647 | NULL, THIS_MODULE); |
| 1648 | nf_ct_helper_init(&sip[4 * i + 3], AF_INET6, IPPROTO_TCP, "sip", |
| 1649 | SIP_PORT, ports[i], i, sip_exp_policy, |
| 1650 | SIP_EXPECT_MAX, |
| 1651 | sizeof(struct nf_ct_sip_master), sip_help_tcp, |
| 1652 | NULL, THIS_MODULE); |
| 1653 | } |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1654 | |
Gao Feng | 82de0be | 2016-07-18 11:39:23 +0800 | [diff] [blame] | 1655 | ret = nf_conntrack_helpers_register(sip, ports_c * 4); |
| 1656 | if (ret < 0) { |
| 1657 | pr_err("failed to register helpers\n"); |
| 1658 | return ret; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1659 | } |
| 1660 | return 0; |
| 1661 | } |
| 1662 | |
| 1663 | module_init(nf_conntrack_sip_init); |
| 1664 | module_exit(nf_conntrack_sip_fini); |