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 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/ctype.h> |
| 15 | #include <linux/skbuff.h> |
| 16 | #include <linux/inet.h> |
| 17 | #include <linux/in.h> |
| 18 | #include <linux/udp.h> |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 19 | #include <linux/tcp.h> |
Yasuyuki Kozakai | 1863f09 | 2006-12-02 22:12:54 -0800 | [diff] [blame] | 20 | #include <linux/netfilter.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 21 | |
| 22 | #include <net/netfilter/nf_conntrack.h> |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 23 | #include <net/netfilter/nf_conntrack_core.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 24 | #include <net/netfilter/nf_conntrack_expect.h> |
| 25 | #include <net/netfilter/nf_conntrack_helper.h> |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 26 | #include <net/netfilter/nf_conntrack_zones.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 27 | #include <linux/netfilter/nf_conntrack_sip.h> |
| 28 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 29 | MODULE_LICENSE("GPL"); |
| 30 | MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>"); |
| 31 | MODULE_DESCRIPTION("SIP connection tracking helper"); |
| 32 | MODULE_ALIAS("ip_conntrack_sip"); |
Pablo Neira Ayuso | 4dc06f9 | 2008-11-17 16:01:42 +0100 | [diff] [blame] | 33 | MODULE_ALIAS_NFCT_HELPER("sip"); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 34 | |
| 35 | #define MAX_PORTS 8 |
| 36 | static unsigned short ports[MAX_PORTS]; |
Stephen Hemminger | 2f0d2f1 | 2008-01-31 04:08:10 -0800 | [diff] [blame] | 37 | static unsigned int ports_c; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 38 | module_param_array(ports, ushort, &ports_c, 0400); |
| 39 | MODULE_PARM_DESC(ports, "port numbers of SIP servers"); |
| 40 | |
| 41 | static unsigned int sip_timeout __read_mostly = SIP_TIMEOUT; |
| 42 | module_param(sip_timeout, uint, 0600); |
| 43 | MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session"); |
| 44 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 45 | static int sip_direct_signalling __read_mostly = 1; |
| 46 | module_param(sip_direct_signalling, int, 0600); |
| 47 | MODULE_PARM_DESC(sip_direct_signalling, "expect incoming calls from registrar " |
| 48 | "only (default 1)"); |
| 49 | |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 50 | static int sip_direct_media __read_mostly = 1; |
| 51 | module_param(sip_direct_media, int, 0600); |
| 52 | MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling " |
| 53 | "endpoints only (default 1)"); |
| 54 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 55 | unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 2a6cfb2 | 2008-03-25 20:16:54 -0700 | [diff] [blame] | 56 | const char **dptr, |
| 57 | unsigned int *datalen) __read_mostly; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 58 | EXPORT_SYMBOL_GPL(nf_nat_sip_hook); |
| 59 | |
Patrick McHardy | 48f8ac2 | 2010-02-11 12:29:38 +0100 | [diff] [blame] | 60 | void (*nf_nat_sip_seq_adjust_hook)(struct sk_buff *skb, s16 off) __read_mostly; |
| 61 | EXPORT_SYMBOL_GPL(nf_nat_sip_seq_adjust_hook); |
| 62 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 63 | unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb, |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 64 | unsigned int dataoff, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 65 | const char **dptr, |
| 66 | unsigned int *datalen, |
| 67 | struct nf_conntrack_expect *exp, |
| 68 | unsigned int matchoff, |
| 69 | unsigned int matchlen) __read_mostly; |
| 70 | EXPORT_SYMBOL_GPL(nf_nat_sip_expect_hook); |
| 71 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 72 | unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 73 | const char **dptr, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 74 | unsigned int *datalen, |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 75 | unsigned int sdpoff, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 76 | enum sdp_header_types type, |
| 77 | enum sdp_header_types term, |
| 78 | const union nf_inet_addr *addr) |
| 79 | __read_mostly; |
| 80 | EXPORT_SYMBOL_GPL(nf_nat_sdp_addr_hook); |
| 81 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 82 | unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 83 | const char **dptr, |
| 84 | unsigned int *datalen, |
| 85 | unsigned int matchoff, |
| 86 | unsigned int matchlen, |
| 87 | u_int16_t port) __read_mostly; |
| 88 | EXPORT_SYMBOL_GPL(nf_nat_sdp_port_hook); |
| 89 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 90 | unsigned int (*nf_nat_sdp_session_hook)(struct sk_buff *skb, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 91 | unsigned int dataoff, |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 92 | const char **dptr, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 93 | unsigned int *datalen, |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 94 | unsigned int sdpoff, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 95 | const union nf_inet_addr *addr) |
| 96 | __read_mostly; |
| 97 | EXPORT_SYMBOL_GPL(nf_nat_sdp_session_hook); |
| 98 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 99 | unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 100 | const char **dptr, |
| 101 | unsigned int *datalen, |
| 102 | struct nf_conntrack_expect *rtp_exp, |
| 103 | struct nf_conntrack_expect *rtcp_exp, |
| 104 | unsigned int mediaoff, |
| 105 | unsigned int medialen, |
| 106 | union nf_inet_addr *rtp_addr) |
| 107 | __read_mostly; |
| 108 | EXPORT_SYMBOL_GPL(nf_nat_sdp_media_hook); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 109 | |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 110 | static int string_len(const struct nf_conn *ct, const char *dptr, |
| 111 | const char *limit, int *shift) |
| 112 | { |
| 113 | int len = 0; |
| 114 | |
| 115 | while (dptr < limit && isalpha(*dptr)) { |
| 116 | dptr++; |
| 117 | len++; |
| 118 | } |
| 119 | return len; |
| 120 | } |
| 121 | |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 122 | static int digits_len(const struct nf_conn *ct, const char *dptr, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 123 | const char *limit, int *shift) |
| 124 | { |
| 125 | int len = 0; |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 126 | while (dptr < limit && isdigit(*dptr)) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 127 | dptr++; |
| 128 | len++; |
| 129 | } |
| 130 | return len; |
| 131 | } |
| 132 | |
Simon Horman | 001985b | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 133 | static int iswordc(const char c) |
| 134 | { |
| 135 | if (isalnum(c) || c == '!' || c == '"' || c == '%' || |
| 136 | (c >= '(' && c <= '/') || c == ':' || c == '<' || c == '>' || |
| 137 | c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' || |
| 138 | c == '{' || c == '}' || c == '~') |
| 139 | return 1; |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | static int word_len(const char *dptr, const char *limit) |
| 144 | { |
| 145 | int len = 0; |
| 146 | while (dptr < limit && iswordc(*dptr)) { |
| 147 | dptr++; |
| 148 | len++; |
| 149 | } |
| 150 | return len; |
| 151 | } |
| 152 | |
| 153 | static int callid_len(const struct nf_conn *ct, const char *dptr, |
| 154 | const char *limit, int *shift) |
| 155 | { |
| 156 | int len, domain_len; |
| 157 | |
| 158 | len = word_len(dptr, limit); |
| 159 | dptr += len; |
| 160 | if (!len || dptr == limit || *dptr != '@') |
| 161 | return len; |
| 162 | dptr++; |
| 163 | len++; |
| 164 | |
| 165 | domain_len = word_len(dptr, limit); |
| 166 | if (!domain_len) |
| 167 | return 0; |
| 168 | return len + domain_len; |
| 169 | } |
| 170 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 171 | /* get media type + port length */ |
| 172 | static int media_len(const struct nf_conn *ct, const char *dptr, |
| 173 | const char *limit, int *shift) |
| 174 | { |
| 175 | int len = string_len(ct, dptr, limit, shift); |
| 176 | |
| 177 | dptr += len; |
| 178 | if (dptr >= limit || *dptr != ' ') |
| 179 | return 0; |
| 180 | len++; |
| 181 | dptr++; |
| 182 | |
| 183 | return len + digits_len(ct, dptr, limit, shift); |
| 184 | } |
| 185 | |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 186 | static int parse_addr(const struct nf_conn *ct, const char *cp, |
| 187 | const char **endp, union nf_inet_addr *addr, |
| 188 | const char *limit) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 189 | { |
| 190 | const char *end; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 191 | int ret = 0; |
| 192 | |
Simon Horman | 5adbb9f | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 193 | if (!ct) |
| 194 | return 0; |
| 195 | |
Patrick McHardy | fa913dd | 2008-04-14 11:15:45 +0200 | [diff] [blame] | 196 | memset(addr, 0, sizeof(*addr)); |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 197 | switch (nf_ct_l3num(ct)) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 198 | case AF_INET: |
| 199 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); |
| 200 | break; |
| 201 | case AF_INET6: |
| 202 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
| 203 | break; |
| 204 | default: |
| 205 | BUG(); |
| 206 | } |
| 207 | |
| 208 | if (ret == 0 || end == cp) |
| 209 | return 0; |
| 210 | if (endp) |
| 211 | *endp = end; |
| 212 | return 1; |
| 213 | } |
| 214 | |
| 215 | /* skip ip address. returns its length. */ |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 216 | static int epaddr_len(const struct nf_conn *ct, const char *dptr, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 217 | const char *limit, int *shift) |
| 218 | { |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 219 | union nf_inet_addr addr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 220 | const char *aux = dptr; |
| 221 | |
| 222 | if (!parse_addr(ct, dptr, &dptr, &addr, limit)) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 223 | pr_debug("ip: %s parse failed.!\n", dptr); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 224 | return 0; |
| 225 | } |
| 226 | |
| 227 | /* Port number */ |
| 228 | if (*dptr == ':') { |
| 229 | dptr++; |
| 230 | dptr += digits_len(ct, dptr, limit, shift); |
| 231 | } |
| 232 | return dptr - aux; |
| 233 | } |
| 234 | |
| 235 | /* get address length, skiping user info. */ |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 236 | 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] | 237 | const char *limit, int *shift) |
| 238 | { |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 239 | const char *start = dptr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 240 | int s = *shift; |
| 241 | |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 242 | /* Search for @, but stop at the end of the line. |
| 243 | * We are inside a sip: URI, so we don't need to worry about |
| 244 | * continuation lines. */ |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 245 | while (dptr < limit && |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 246 | *dptr != '@' && *dptr != '\r' && *dptr != '\n') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 247 | (*shift)++; |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 248 | dptr++; |
| 249 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 250 | |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 251 | if (dptr < limit && *dptr == '@') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 252 | dptr++; |
| 253 | (*shift)++; |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 254 | } else { |
| 255 | dptr = start; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 256 | *shift = s; |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 257 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 258 | |
| 259 | return epaddr_len(ct, dptr, limit, shift); |
| 260 | } |
| 261 | |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 262 | /* Parse a SIP request line of the form: |
| 263 | * |
| 264 | * Request-Line = Method SP Request-URI SP SIP-Version CRLF |
| 265 | * |
| 266 | * and return the offset and length of the address contained in the Request-URI. |
| 267 | */ |
| 268 | int ct_sip_parse_request(const struct nf_conn *ct, |
| 269 | const char *dptr, unsigned int datalen, |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 270 | unsigned int *matchoff, unsigned int *matchlen, |
| 271 | union nf_inet_addr *addr, __be16 *port) |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 272 | { |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 273 | const char *start = dptr, *limit = dptr + datalen, *end; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 274 | unsigned int mlen; |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 275 | unsigned int p; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 276 | int shift = 0; |
| 277 | |
| 278 | /* Skip method and following whitespace */ |
| 279 | mlen = string_len(ct, dptr, limit, NULL); |
| 280 | if (!mlen) |
| 281 | return 0; |
| 282 | dptr += mlen; |
| 283 | if (++dptr >= limit) |
| 284 | return 0; |
| 285 | |
| 286 | /* Find SIP URI */ |
Patrick McHardy | 54101f4 | 2010-02-11 12:23:12 +0100 | [diff] [blame] | 287 | for (; dptr < limit - strlen("sip:"); dptr++) { |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 288 | if (*dptr == '\r' || *dptr == '\n') |
| 289 | return -1; |
Patrick McHardy | 54101f4 | 2010-02-11 12:23:12 +0100 | [diff] [blame] | 290 | if (strnicmp(dptr, "sip:", strlen("sip:")) == 0) { |
| 291 | dptr += strlen("sip:"); |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 292 | break; |
Patrick McHardy | 54101f4 | 2010-02-11 12:23:12 +0100 | [diff] [blame] | 293 | } |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 294 | } |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 295 | if (!skp_epaddr_len(ct, dptr, limit, &shift)) |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 296 | return 0; |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 297 | dptr += shift; |
| 298 | |
| 299 | if (!parse_addr(ct, dptr, &end, addr, limit)) |
| 300 | return -1; |
| 301 | if (end < limit && *end == ':') { |
| 302 | end++; |
| 303 | p = simple_strtoul(end, (char **)&end, 10); |
| 304 | if (p < 1024 || p > 65535) |
| 305 | return -1; |
| 306 | *port = htons(p); |
| 307 | } else |
| 308 | *port = htons(SIP_PORT); |
| 309 | |
| 310 | if (end == dptr) |
| 311 | return 0; |
| 312 | *matchoff = dptr - start; |
| 313 | *matchlen = end - dptr; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 314 | return 1; |
| 315 | } |
| 316 | EXPORT_SYMBOL_GPL(ct_sip_parse_request); |
| 317 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 318 | /* SIP header parsing: SIP headers are located at the beginning of a line, but |
| 319 | * may span several lines, in which case the continuation lines begin with a |
| 320 | * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or |
| 321 | * CRLF, RFC 3261 allows only CRLF, we support both. |
| 322 | * |
| 323 | * Headers are followed by (optionally) whitespace, a colon, again (optionally) |
| 324 | * whitespace and the values. Whitespace in this context means any amount of |
| 325 | * tabs, spaces and continuation lines, which are treated as a single whitespace |
| 326 | * character. |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 327 | * |
Daniel Mack | 3ad2f3f | 2010-02-03 08:01:28 +0800 | [diff] [blame] | 328 | * 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] | 329 | * equivalent to multiple headers. |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 330 | */ |
| 331 | static const struct sip_header ct_sip_hdrs[] = { |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 332 | [SIP_HDR_CSEQ] = SIP_HDR("CSeq", NULL, NULL, digits_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 333 | [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len), |
| 334 | [SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len), |
| 335 | [SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len), |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 336 | [SIP_HDR_VIA_UDP] = SIP_HDR("Via", "v", "UDP ", epaddr_len), |
| 337 | [SIP_HDR_VIA_TCP] = SIP_HDR("Via", "v", "TCP ", epaddr_len), |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 338 | [SIP_HDR_EXPIRES] = SIP_HDR("Expires", NULL, NULL, digits_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 339 | [SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len), |
Simon Horman | 001985b | 2010-08-22 21:37:51 +0900 | [diff] [blame] | 340 | [SIP_HDR_CALL_ID] = SIP_HDR("Call-Id", "i", NULL, callid_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 341 | }; |
| 342 | |
| 343 | static const char *sip_follow_continuation(const char *dptr, const char *limit) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 344 | { |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 345 | /* Walk past newline */ |
| 346 | if (++dptr >= limit) |
| 347 | return NULL; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 348 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 349 | /* Skip '\n' in CR LF */ |
| 350 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 351 | if (++dptr >= limit) |
| 352 | return NULL; |
| 353 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 354 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 355 | /* Continuation line? */ |
| 356 | if (*dptr != ' ' && *dptr != '\t') |
| 357 | return NULL; |
| 358 | |
| 359 | /* skip leading whitespace */ |
| 360 | for (; dptr < limit; dptr++) { |
| 361 | if (*dptr != ' ' && *dptr != '\t') |
| 362 | break; |
| 363 | } |
| 364 | return dptr; |
| 365 | } |
| 366 | |
| 367 | static const char *sip_skip_whitespace(const char *dptr, const char *limit) |
| 368 | { |
| 369 | for (; dptr < limit; dptr++) { |
| 370 | if (*dptr == ' ') |
| 371 | continue; |
| 372 | if (*dptr != '\r' && *dptr != '\n') |
| 373 | break; |
| 374 | dptr = sip_follow_continuation(dptr, limit); |
| 375 | if (dptr == NULL) |
| 376 | return NULL; |
| 377 | } |
| 378 | return dptr; |
| 379 | } |
| 380 | |
| 381 | /* Search within a SIP header value, dealing with continuation lines */ |
| 382 | static const char *ct_sip_header_search(const char *dptr, const char *limit, |
| 383 | const char *needle, unsigned int len) |
| 384 | { |
| 385 | for (limit -= len; dptr < limit; dptr++) { |
| 386 | if (*dptr == '\r' || *dptr == '\n') { |
| 387 | dptr = sip_follow_continuation(dptr, limit); |
| 388 | if (dptr == NULL) |
| 389 | break; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 390 | continue; |
| 391 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 392 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 393 | if (strnicmp(dptr, needle, len) == 0) |
| 394 | return dptr; |
| 395 | } |
| 396 | return NULL; |
| 397 | } |
| 398 | |
| 399 | int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, |
| 400 | unsigned int dataoff, unsigned int datalen, |
| 401 | enum sip_header_types type, |
| 402 | unsigned int *matchoff, unsigned int *matchlen) |
| 403 | { |
| 404 | const struct sip_header *hdr = &ct_sip_hdrs[type]; |
| 405 | const char *start = dptr, *limit = dptr + datalen; |
| 406 | int shift = 0; |
| 407 | |
| 408 | for (dptr += dataoff; dptr < limit; dptr++) { |
| 409 | /* Find beginning of line */ |
| 410 | if (*dptr != '\r' && *dptr != '\n') |
| 411 | continue; |
| 412 | if (++dptr >= limit) |
| 413 | break; |
| 414 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 415 | if (++dptr >= limit) |
| 416 | break; |
| 417 | } |
| 418 | |
| 419 | /* Skip continuation lines */ |
| 420 | if (*dptr == ' ' || *dptr == '\t') |
| 421 | continue; |
| 422 | |
| 423 | /* Find header. Compact headers must be followed by a |
| 424 | * non-alphabetic character to avoid mismatches. */ |
| 425 | if (limit - dptr >= hdr->len && |
| 426 | strnicmp(dptr, hdr->name, hdr->len) == 0) |
| 427 | dptr += hdr->len; |
| 428 | else if (hdr->cname && limit - dptr >= hdr->clen + 1 && |
| 429 | strnicmp(dptr, hdr->cname, hdr->clen) == 0 && |
Patrick McHardy | 135d018 | 2010-01-19 19:06:59 +0100 | [diff] [blame] | 430 | !isalpha(*(dptr + hdr->clen))) |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 431 | dptr += hdr->clen; |
| 432 | else |
| 433 | continue; |
| 434 | |
| 435 | /* Find and skip colon */ |
| 436 | dptr = sip_skip_whitespace(dptr, limit); |
| 437 | if (dptr == NULL) |
| 438 | break; |
| 439 | if (*dptr != ':' || ++dptr >= limit) |
| 440 | break; |
| 441 | |
| 442 | /* Skip whitespace after colon */ |
| 443 | dptr = sip_skip_whitespace(dptr, limit); |
| 444 | if (dptr == NULL) |
| 445 | break; |
| 446 | |
| 447 | *matchoff = dptr - start; |
| 448 | if (hdr->search) { |
| 449 | dptr = ct_sip_header_search(dptr, limit, hdr->search, |
| 450 | hdr->slen); |
| 451 | if (!dptr) |
| 452 | return -1; |
| 453 | dptr += hdr->slen; |
| 454 | } |
| 455 | |
| 456 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 457 | if (!*matchlen) |
| 458 | return -1; |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 459 | *matchoff = dptr - start + shift; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 460 | return 1; |
| 461 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 462 | return 0; |
| 463 | } |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 464 | EXPORT_SYMBOL_GPL(ct_sip_get_header); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 465 | |
Daniel Mack | 3ad2f3f | 2010-02-03 08:01:28 +0800 | [diff] [blame] | 466 | /* Get next header field in a list of comma separated values */ |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 467 | static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr, |
| 468 | unsigned int dataoff, unsigned int datalen, |
| 469 | enum sip_header_types type, |
| 470 | unsigned int *matchoff, unsigned int *matchlen) |
| 471 | { |
| 472 | const struct sip_header *hdr = &ct_sip_hdrs[type]; |
| 473 | const char *start = dptr, *limit = dptr + datalen; |
| 474 | int shift = 0; |
| 475 | |
| 476 | dptr += dataoff; |
| 477 | |
| 478 | dptr = ct_sip_header_search(dptr, limit, ",", strlen(",")); |
| 479 | if (!dptr) |
| 480 | return 0; |
| 481 | |
| 482 | dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen); |
| 483 | if (!dptr) |
| 484 | return 0; |
| 485 | dptr += hdr->slen; |
| 486 | |
| 487 | *matchoff = dptr - start; |
| 488 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
| 489 | if (!*matchlen) |
| 490 | return -1; |
| 491 | *matchoff += shift; |
| 492 | return 1; |
| 493 | } |
| 494 | |
| 495 | /* Walk through headers until a parsable one is found or no header of the |
| 496 | * given type is left. */ |
| 497 | static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, |
| 498 | unsigned int dataoff, unsigned int datalen, |
| 499 | enum sip_header_types type, int *in_header, |
| 500 | unsigned int *matchoff, unsigned int *matchlen) |
| 501 | { |
| 502 | int ret; |
| 503 | |
| 504 | if (in_header && *in_header) { |
| 505 | while (1) { |
| 506 | ret = ct_sip_next_header(ct, dptr, dataoff, datalen, |
| 507 | type, matchoff, matchlen); |
| 508 | if (ret > 0) |
| 509 | return ret; |
| 510 | if (ret == 0) |
| 511 | break; |
| 512 | dataoff += *matchoff; |
| 513 | } |
| 514 | *in_header = 0; |
| 515 | } |
| 516 | |
| 517 | while (1) { |
| 518 | ret = ct_sip_get_header(ct, dptr, dataoff, datalen, |
| 519 | type, matchoff, matchlen); |
| 520 | if (ret > 0) |
| 521 | break; |
| 522 | if (ret == 0) |
| 523 | return ret; |
| 524 | dataoff += *matchoff; |
| 525 | } |
| 526 | |
| 527 | if (in_header) |
| 528 | *in_header = 1; |
| 529 | return 1; |
| 530 | } |
| 531 | |
| 532 | /* Locate a SIP header, parse the URI and return the offset and length of |
| 533 | * the address as well as the address and port themselves. A stream of |
| 534 | * headers can be parsed by handing in a non-NULL datalen and in_header |
| 535 | * pointer. |
| 536 | */ |
| 537 | int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, |
| 538 | unsigned int *dataoff, unsigned int datalen, |
| 539 | enum sip_header_types type, int *in_header, |
| 540 | unsigned int *matchoff, unsigned int *matchlen, |
| 541 | union nf_inet_addr *addr, __be16 *port) |
| 542 | { |
| 543 | const char *c, *limit = dptr + datalen; |
| 544 | unsigned int p; |
| 545 | int ret; |
| 546 | |
| 547 | ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen, |
| 548 | type, in_header, matchoff, matchlen); |
| 549 | WARN_ON(ret < 0); |
| 550 | if (ret == 0) |
| 551 | return ret; |
| 552 | |
| 553 | if (!parse_addr(ct, dptr + *matchoff, &c, addr, limit)) |
| 554 | return -1; |
| 555 | if (*c == ':') { |
| 556 | c++; |
| 557 | p = simple_strtoul(c, (char **)&c, 10); |
| 558 | if (p < 1024 || p > 65535) |
| 559 | return -1; |
| 560 | *port = htons(p); |
| 561 | } else |
| 562 | *port = htons(SIP_PORT); |
| 563 | |
| 564 | if (dataoff) |
| 565 | *dataoff = c - dptr; |
| 566 | return 1; |
| 567 | } |
| 568 | EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri); |
| 569 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 570 | static int ct_sip_parse_param(const struct nf_conn *ct, const char *dptr, |
| 571 | unsigned int dataoff, unsigned int datalen, |
| 572 | const char *name, |
| 573 | unsigned int *matchoff, unsigned int *matchlen) |
| 574 | { |
| 575 | const char *limit = dptr + datalen; |
| 576 | const char *start; |
| 577 | const char *end; |
| 578 | |
| 579 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 580 | if (!limit) |
| 581 | limit = dptr + datalen; |
| 582 | |
| 583 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 584 | if (!start) |
| 585 | return 0; |
| 586 | start += strlen(name); |
| 587 | |
| 588 | end = ct_sip_header_search(start, limit, ";", strlen(";")); |
| 589 | if (!end) |
| 590 | end = limit; |
| 591 | |
| 592 | *matchoff = start - dptr; |
| 593 | *matchlen = end - start; |
| 594 | return 1; |
| 595 | } |
| 596 | |
Patrick McHardy | 2bbb211 | 2008-03-25 20:24:24 -0700 | [diff] [blame] | 597 | /* Parse address from header parameter and return address, offset and length */ |
| 598 | int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, |
| 599 | unsigned int dataoff, unsigned int datalen, |
| 600 | const char *name, |
| 601 | unsigned int *matchoff, unsigned int *matchlen, |
| 602 | union nf_inet_addr *addr) |
| 603 | { |
| 604 | const char *limit = dptr + datalen; |
| 605 | const char *start, *end; |
| 606 | |
| 607 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 608 | if (!limit) |
| 609 | limit = dptr + datalen; |
| 610 | |
| 611 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 612 | if (!start) |
| 613 | return 0; |
| 614 | |
| 615 | start += strlen(name); |
| 616 | if (!parse_addr(ct, start, &end, addr, limit)) |
| 617 | return 0; |
| 618 | *matchoff = start - dptr; |
| 619 | *matchlen = end - start; |
| 620 | return 1; |
| 621 | } |
| 622 | EXPORT_SYMBOL_GPL(ct_sip_parse_address_param); |
| 623 | |
| 624 | /* Parse numerical header parameter and return value, offset and length */ |
| 625 | int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr, |
| 626 | unsigned int dataoff, unsigned int datalen, |
| 627 | const char *name, |
| 628 | unsigned int *matchoff, unsigned int *matchlen, |
| 629 | unsigned int *val) |
| 630 | { |
| 631 | const char *limit = dptr + datalen; |
| 632 | const char *start; |
| 633 | char *end; |
| 634 | |
| 635 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 636 | if (!limit) |
| 637 | limit = dptr + datalen; |
| 638 | |
| 639 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 640 | if (!start) |
| 641 | return 0; |
| 642 | |
| 643 | start += strlen(name); |
| 644 | *val = simple_strtoul(start, &end, 0); |
| 645 | if (start == end) |
| 646 | return 0; |
| 647 | if (matchoff && matchlen) { |
| 648 | *matchoff = start - dptr; |
| 649 | *matchlen = end - start; |
| 650 | } |
| 651 | return 1; |
| 652 | } |
| 653 | EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param); |
| 654 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 655 | static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, |
| 656 | unsigned int dataoff, unsigned int datalen, |
| 657 | u8 *proto) |
| 658 | { |
| 659 | unsigned int matchoff, matchlen; |
| 660 | |
| 661 | if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=", |
| 662 | &matchoff, &matchlen)) { |
| 663 | if (!strnicmp(dptr + matchoff, "TCP", strlen("TCP"))) |
| 664 | *proto = IPPROTO_TCP; |
| 665 | else if (!strnicmp(dptr + matchoff, "UDP", strlen("UDP"))) |
| 666 | *proto = IPPROTO_UDP; |
| 667 | else |
| 668 | return 0; |
| 669 | |
| 670 | if (*proto != nf_ct_protonum(ct)) |
| 671 | return 0; |
| 672 | } else |
| 673 | *proto = nf_ct_protonum(ct); |
| 674 | |
| 675 | return 1; |
| 676 | } |
| 677 | |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 678 | /* SDP header parsing: a SDP session description contains an ordered set of |
| 679 | * headers, starting with a section containing general session parameters, |
| 680 | * optionally followed by multiple media descriptions. |
| 681 | * |
| 682 | * SDP headers always start at the beginning of a line. According to RFC 2327: |
| 683 | * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should |
| 684 | * be tolerant and also accept records terminated with a single newline |
| 685 | * character". We handle both cases. |
| 686 | */ |
| 687 | static const struct sip_header ct_sdp_hdrs[] = { |
| 688 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), |
| 689 | [SDP_HDR_OWNER_IP4] = SDP_HDR("o=", "IN IP4 ", epaddr_len), |
| 690 | [SDP_HDR_CONNECTION_IP4] = SDP_HDR("c=", "IN IP4 ", epaddr_len), |
| 691 | [SDP_HDR_OWNER_IP6] = SDP_HDR("o=", "IN IP6 ", epaddr_len), |
| 692 | [SDP_HDR_CONNECTION_IP6] = SDP_HDR("c=", "IN IP6 ", epaddr_len), |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 693 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 694 | }; |
| 695 | |
| 696 | /* Linear string search within SDP header values */ |
| 697 | static const char *ct_sdp_header_search(const char *dptr, const char *limit, |
| 698 | const char *needle, unsigned int len) |
| 699 | { |
| 700 | for (limit -= len; dptr < limit; dptr++) { |
| 701 | if (*dptr == '\r' || *dptr == '\n') |
| 702 | break; |
| 703 | if (strncmp(dptr, needle, len) == 0) |
| 704 | return dptr; |
| 705 | } |
| 706 | return NULL; |
| 707 | } |
| 708 | |
| 709 | /* Locate a SDP header (optionally a substring within the header value), |
| 710 | * optionally stopping at the first occurence of the term header, parse |
| 711 | * it and return the offset and length of the data we're interested in. |
| 712 | */ |
| 713 | int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr, |
| 714 | unsigned int dataoff, unsigned int datalen, |
| 715 | enum sdp_header_types type, |
| 716 | enum sdp_header_types term, |
| 717 | unsigned int *matchoff, unsigned int *matchlen) |
| 718 | { |
| 719 | const struct sip_header *hdr = &ct_sdp_hdrs[type]; |
| 720 | const struct sip_header *thdr = &ct_sdp_hdrs[term]; |
| 721 | const char *start = dptr, *limit = dptr + datalen; |
| 722 | int shift = 0; |
| 723 | |
| 724 | for (dptr += dataoff; dptr < limit; dptr++) { |
| 725 | /* Find beginning of line */ |
| 726 | if (*dptr != '\r' && *dptr != '\n') |
| 727 | continue; |
| 728 | if (++dptr >= limit) |
| 729 | break; |
| 730 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 731 | if (++dptr >= limit) |
| 732 | break; |
| 733 | } |
| 734 | |
| 735 | if (term != SDP_HDR_UNSPEC && |
| 736 | limit - dptr >= thdr->len && |
| 737 | strnicmp(dptr, thdr->name, thdr->len) == 0) |
| 738 | break; |
| 739 | else if (limit - dptr >= hdr->len && |
| 740 | strnicmp(dptr, hdr->name, hdr->len) == 0) |
| 741 | dptr += hdr->len; |
| 742 | else |
| 743 | continue; |
| 744 | |
| 745 | *matchoff = dptr - start; |
| 746 | if (hdr->search) { |
| 747 | dptr = ct_sdp_header_search(dptr, limit, hdr->search, |
| 748 | hdr->slen); |
| 749 | if (!dptr) |
| 750 | return -1; |
| 751 | dptr += hdr->slen; |
| 752 | } |
| 753 | |
| 754 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
| 755 | if (!*matchlen) |
| 756 | return -1; |
| 757 | *matchoff = dptr - start + shift; |
| 758 | return 1; |
| 759 | } |
| 760 | return 0; |
| 761 | } |
| 762 | EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header); |
| 763 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 764 | static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr, |
| 765 | unsigned int dataoff, unsigned int datalen, |
| 766 | enum sdp_header_types type, |
| 767 | enum sdp_header_types term, |
| 768 | unsigned int *matchoff, unsigned int *matchlen, |
| 769 | union nf_inet_addr *addr) |
| 770 | { |
| 771 | int ret; |
| 772 | |
| 773 | ret = ct_sip_get_sdp_header(ct, dptr, dataoff, datalen, type, term, |
| 774 | matchoff, matchlen); |
| 775 | if (ret <= 0) |
| 776 | return ret; |
| 777 | |
| 778 | if (!parse_addr(ct, dptr + *matchoff, NULL, addr, |
| 779 | dptr + *matchoff + *matchlen)) |
| 780 | return -1; |
| 781 | return 1; |
| 782 | } |
| 783 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 784 | static int refresh_signalling_expectation(struct nf_conn *ct, |
| 785 | union nf_inet_addr *addr, |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 786 | u8 proto, __be16 port, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 787 | unsigned int expires) |
| 788 | { |
| 789 | struct nf_conn_help *help = nfct_help(ct); |
| 790 | struct nf_conntrack_expect *exp; |
| 791 | struct hlist_node *n, *next; |
| 792 | int found = 0; |
| 793 | |
| 794 | spin_lock_bh(&nf_conntrack_lock); |
| 795 | hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) { |
| 796 | if (exp->class != SIP_EXPECT_SIGNALLING || |
| 797 | !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) || |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 798 | exp->tuple.dst.protonum != proto || |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 799 | exp->tuple.dst.u.udp.port != port) |
| 800 | continue; |
| 801 | if (!del_timer(&exp->timeout)) |
| 802 | continue; |
| 803 | exp->flags &= ~NF_CT_EXPECT_INACTIVE; |
| 804 | exp->timeout.expires = jiffies + expires * HZ; |
| 805 | add_timer(&exp->timeout); |
| 806 | found = 1; |
| 807 | break; |
| 808 | } |
| 809 | spin_unlock_bh(&nf_conntrack_lock); |
| 810 | return found; |
| 811 | } |
| 812 | |
| 813 | static void flush_expectations(struct nf_conn *ct, bool media) |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 814 | { |
| 815 | struct nf_conn_help *help = nfct_help(ct); |
| 816 | struct nf_conntrack_expect *exp; |
| 817 | struct hlist_node *n, *next; |
| 818 | |
| 819 | spin_lock_bh(&nf_conntrack_lock); |
| 820 | hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) { |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 821 | if ((exp->class != SIP_EXPECT_SIGNALLING) ^ media) |
| 822 | continue; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 823 | if (!del_timer(&exp->timeout)) |
| 824 | continue; |
| 825 | nf_ct_unlink_expect(exp); |
| 826 | nf_ct_expect_put(exp); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 827 | if (!media) |
| 828 | break; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 829 | } |
| 830 | spin_unlock_bh(&nf_conntrack_lock); |
| 831 | } |
| 832 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 833 | static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 834 | const char **dptr, unsigned int *datalen, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 835 | union nf_inet_addr *daddr, __be16 port, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 836 | enum sip_expectation_classes class, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 837 | unsigned int mediaoff, unsigned int medialen) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 838 | { |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 839 | struct nf_conntrack_expect *exp, *rtp_exp, *rtcp_exp; |
Patrick McHardy | 212440a | 2008-03-25 20:17:13 -0700 | [diff] [blame] | 840 | enum ip_conntrack_info ctinfo; |
| 841 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Alexey Dobriyan | a5c3a80 | 2008-10-08 11:35:09 +0200 | [diff] [blame] | 842 | struct net *net = nf_ct_net(ct); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 843 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 844 | union nf_inet_addr *saddr; |
| 845 | struct nf_conntrack_tuple tuple; |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 846 | int direct_rtp = 0, skip_expect = 0, ret = NF_DROP; |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 847 | u_int16_t base_port; |
| 848 | __be16 rtp_port, rtcp_port; |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 849 | typeof(nf_nat_sdp_port_hook) nf_nat_sdp_port; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 850 | typeof(nf_nat_sdp_media_hook) nf_nat_sdp_media; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 851 | |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 852 | saddr = NULL; |
| 853 | if (sip_direct_media) { |
| 854 | if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3)) |
| 855 | return NF_ACCEPT; |
| 856 | saddr = &ct->tuplehash[!dir].tuple.src.u3; |
| 857 | } |
| 858 | |
| 859 | /* We need to check whether the registration exists before attempting |
| 860 | * to register it since we can see the same media description multiple |
| 861 | * times on different connections in case multiple endpoints receive |
| 862 | * the same call. |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 863 | * |
| 864 | * RTP optimization: if we find a matching media channel expectation |
| 865 | * and both the expectation and this connection are SNATed, we assume |
| 866 | * both sides can reach each other directly and use the final |
| 867 | * destination address from the expectation. We still need to keep |
| 868 | * the NATed expectations for media that might arrive from the |
| 869 | * outside, and additionally need to expect the direct RTP stream |
| 870 | * in case it passes through us even without NAT. |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 871 | */ |
| 872 | memset(&tuple, 0, sizeof(tuple)); |
| 873 | if (saddr) |
| 874 | tuple.src.u3 = *saddr; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 875 | tuple.src.l3num = nf_ct_l3num(ct); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 876 | tuple.dst.protonum = IPPROTO_UDP; |
| 877 | tuple.dst.u3 = *daddr; |
| 878 | tuple.dst.u.udp.port = port; |
| 879 | |
| 880 | rcu_read_lock(); |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 881 | do { |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 882 | exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 883 | |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 884 | if (!exp || exp->master == ct || |
| 885 | nfct_help(exp->master)->helper != nfct_help(ct)->helper || |
| 886 | exp->class != class) |
| 887 | break; |
Patrick McHardy | e1f9a46 | 2008-04-19 17:53:52 -0700 | [diff] [blame] | 888 | #ifdef CONFIG_NF_NAT_NEEDED |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 889 | if (exp->tuple.src.l3num == AF_INET && !direct_rtp && |
| 890 | (exp->saved_ip != exp->tuple.dst.u3.ip || |
| 891 | exp->saved_proto.udp.port != exp->tuple.dst.u.udp.port) && |
| 892 | ct->status & IPS_NAT_MASK) { |
| 893 | daddr->ip = exp->saved_ip; |
| 894 | tuple.dst.u3.ip = exp->saved_ip; |
| 895 | tuple.dst.u.udp.port = exp->saved_proto.udp.port; |
| 896 | direct_rtp = 1; |
| 897 | } else |
Patrick McHardy | e1f9a46 | 2008-04-19 17:53:52 -0700 | [diff] [blame] | 898 | #endif |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 899 | skip_expect = 1; |
| 900 | } while (!skip_expect); |
| 901 | rcu_read_unlock(); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 902 | |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 903 | base_port = ntohs(tuple.dst.u.udp.port) & ~1; |
| 904 | rtp_port = htons(base_port); |
| 905 | rtcp_port = htons(base_port + 1); |
| 906 | |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 907 | if (direct_rtp) { |
| 908 | nf_nat_sdp_port = rcu_dereference(nf_nat_sdp_port_hook); |
| 909 | if (nf_nat_sdp_port && |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 910 | !nf_nat_sdp_port(skb, dataoff, dptr, datalen, |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 911 | mediaoff, medialen, ntohs(rtp_port))) |
| 912 | goto err1; |
| 913 | } |
| 914 | |
| 915 | if (skip_expect) |
| 916 | return NF_ACCEPT; |
| 917 | |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 918 | rtp_exp = nf_ct_expect_alloc(ct); |
| 919 | if (rtp_exp == NULL) |
| 920 | goto err1; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 921 | 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] | 922 | IPPROTO_UDP, NULL, &rtp_port); |
| 923 | |
| 924 | rtcp_exp = nf_ct_expect_alloc(ct); |
| 925 | if (rtcp_exp == NULL) |
| 926 | goto err2; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 927 | 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] | 928 | IPPROTO_UDP, NULL, &rtcp_port); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 929 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 930 | nf_nat_sdp_media = rcu_dereference(nf_nat_sdp_media_hook); |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 931 | if (nf_nat_sdp_media && ct->status & IPS_NAT_MASK && !direct_rtp) |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 932 | ret = nf_nat_sdp_media(skb, dataoff, dptr, datalen, |
| 933 | rtp_exp, rtcp_exp, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 934 | mediaoff, medialen, daddr); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 935 | else { |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 936 | if (nf_ct_expect_related(rtp_exp) == 0) { |
| 937 | if (nf_ct_expect_related(rtcp_exp) != 0) |
| 938 | nf_ct_unexpect_related(rtp_exp); |
| 939 | else |
| 940 | ret = NF_ACCEPT; |
| 941 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 942 | } |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 943 | nf_ct_expect_put(rtcp_exp); |
| 944 | err2: |
| 945 | nf_ct_expect_put(rtp_exp); |
| 946 | err1: |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 947 | return ret; |
| 948 | } |
| 949 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 950 | static const struct sdp_media_type sdp_media_types[] = { |
| 951 | SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO), |
| 952 | SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO), |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 953 | SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE), |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 954 | }; |
| 955 | |
| 956 | static const struct sdp_media_type *sdp_media_type(const char *dptr, |
| 957 | unsigned int matchoff, |
| 958 | unsigned int matchlen) |
| 959 | { |
| 960 | const struct sdp_media_type *t; |
| 961 | unsigned int i; |
| 962 | |
| 963 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); i++) { |
| 964 | t = &sdp_media_types[i]; |
| 965 | if (matchlen < t->len || |
| 966 | strncmp(dptr + matchoff, t->name, t->len)) |
| 967 | continue; |
| 968 | return t; |
| 969 | } |
| 970 | return NULL; |
| 971 | } |
| 972 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 973 | static int process_sdp(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 974 | const char **dptr, unsigned int *datalen, |
| 975 | unsigned int cseq) |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 976 | { |
| 977 | enum ip_conntrack_info ctinfo; |
| 978 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 979 | unsigned int matchoff, matchlen; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 980 | unsigned int mediaoff, medialen; |
| 981 | unsigned int sdpoff; |
| 982 | unsigned int caddr_len, maddr_len; |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 983 | unsigned int i; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 984 | union nf_inet_addr caddr, maddr, rtp_addr; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 985 | unsigned int port; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 986 | enum sdp_header_types c_hdr; |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 987 | const struct sdp_media_type *t; |
| 988 | int ret = NF_ACCEPT; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 989 | typeof(nf_nat_sdp_addr_hook) nf_nat_sdp_addr; |
| 990 | typeof(nf_nat_sdp_session_hook) nf_nat_sdp_session; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 991 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 992 | nf_nat_sdp_addr = rcu_dereference(nf_nat_sdp_addr_hook); |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 993 | c_hdr = nf_ct_l3num(ct) == AF_INET ? SDP_HDR_CONNECTION_IP4 : |
| 994 | SDP_HDR_CONNECTION_IP6; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 995 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 996 | /* Find beginning of session description */ |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 997 | if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 998 | SDP_HDR_VERSION, SDP_HDR_UNSPEC, |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 999 | &matchoff, &matchlen) <= 0) |
| 1000 | return NF_ACCEPT; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1001 | sdpoff = matchoff; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1002 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1003 | /* The connection information is contained in the session description |
| 1004 | * and/or once per media description. The first media description marks |
| 1005 | * the end of the session description. */ |
| 1006 | caddr_len = 0; |
| 1007 | if (ct_sip_parse_sdp_addr(ct, *dptr, sdpoff, *datalen, |
| 1008 | c_hdr, SDP_HDR_MEDIA, |
| 1009 | &matchoff, &matchlen, &caddr) > 0) |
| 1010 | caddr_len = matchlen; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1011 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1012 | mediaoff = sdpoff; |
| 1013 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); ) { |
| 1014 | if (ct_sip_get_sdp_header(ct, *dptr, mediaoff, *datalen, |
| 1015 | SDP_HDR_MEDIA, SDP_HDR_UNSPEC, |
| 1016 | &mediaoff, &medialen) <= 0) |
| 1017 | break; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1018 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1019 | /* Get media type and port number. A media port value of zero |
| 1020 | * indicates an inactive stream. */ |
| 1021 | t = sdp_media_type(*dptr, mediaoff, medialen); |
| 1022 | if (!t) { |
| 1023 | mediaoff += medialen; |
| 1024 | continue; |
| 1025 | } |
| 1026 | mediaoff += t->len; |
| 1027 | medialen -= t->len; |
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 | port = simple_strtoul(*dptr + mediaoff, NULL, 10); |
| 1030 | if (port == 0) |
| 1031 | continue; |
| 1032 | if (port < 1024 || port > 65535) |
| 1033 | return NF_DROP; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1034 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1035 | /* The media description overrides the session description. */ |
| 1036 | maddr_len = 0; |
| 1037 | if (ct_sip_parse_sdp_addr(ct, *dptr, mediaoff, *datalen, |
| 1038 | c_hdr, SDP_HDR_MEDIA, |
| 1039 | &matchoff, &matchlen, &maddr) > 0) { |
| 1040 | maddr_len = matchlen; |
| 1041 | memcpy(&rtp_addr, &maddr, sizeof(rtp_addr)); |
| 1042 | } else if (caddr_len) |
| 1043 | memcpy(&rtp_addr, &caddr, sizeof(rtp_addr)); |
| 1044 | else |
| 1045 | return NF_DROP; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1046 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1047 | ret = set_expected_rtp_rtcp(skb, dataoff, dptr, datalen, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1048 | &rtp_addr, htons(port), t->class, |
| 1049 | mediaoff, medialen); |
| 1050 | if (ret != NF_ACCEPT) |
| 1051 | return ret; |
| 1052 | |
| 1053 | /* Update media connection address if present */ |
| 1054 | if (maddr_len && nf_nat_sdp_addr && ct->status & IPS_NAT_MASK) { |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1055 | ret = nf_nat_sdp_addr(skb, dataoff, dptr, datalen, |
| 1056 | mediaoff, c_hdr, SDP_HDR_MEDIA, |
| 1057 | &rtp_addr); |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1058 | if (ret != NF_ACCEPT) |
| 1059 | return ret; |
| 1060 | } |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1061 | i++; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1062 | } |
| 1063 | |
| 1064 | /* Update session connection and owner addresses */ |
| 1065 | nf_nat_sdp_session = rcu_dereference(nf_nat_sdp_session_hook); |
| 1066 | if (nf_nat_sdp_session && ct->status & IPS_NAT_MASK) |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1067 | ret = nf_nat_sdp_session(skb, dataoff, dptr, datalen, sdpoff, |
| 1068 | &rtp_addr); |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 1069 | |
| 1070 | return ret; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1071 | } |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1072 | static int process_invite_response(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1073 | const char **dptr, unsigned int *datalen, |
| 1074 | unsigned int cseq, unsigned int code) |
| 1075 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1076 | enum ip_conntrack_info ctinfo; |
| 1077 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1078 | struct nf_conn_help *help = nfct_help(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1079 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1080 | if ((code >= 100 && code <= 199) || |
| 1081 | (code >= 200 && code <= 299)) |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1082 | return process_sdp(skb, dataoff, dptr, datalen, cseq); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1083 | else if (help->help.ct_sip_info.invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1084 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1085 | return NF_ACCEPT; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1086 | } |
| 1087 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1088 | static int process_update_response(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1089 | const char **dptr, unsigned int *datalen, |
| 1090 | unsigned int cseq, unsigned int code) |
| 1091 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1092 | enum ip_conntrack_info ctinfo; |
| 1093 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1094 | struct nf_conn_help *help = nfct_help(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1095 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1096 | if ((code >= 100 && code <= 199) || |
| 1097 | (code >= 200 && code <= 299)) |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1098 | return process_sdp(skb, dataoff, dptr, datalen, cseq); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1099 | else if (help->help.ct_sip_info.invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1100 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1101 | return NF_ACCEPT; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1102 | } |
| 1103 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1104 | static int process_prack_response(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1105 | const char **dptr, unsigned int *datalen, |
| 1106 | unsigned int cseq, unsigned int code) |
| 1107 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1108 | enum ip_conntrack_info ctinfo; |
| 1109 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1110 | struct nf_conn_help *help = nfct_help(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1111 | |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1112 | if ((code >= 100 && code <= 199) || |
| 1113 | (code >= 200 && code <= 299)) |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1114 | return process_sdp(skb, dataoff, dptr, datalen, cseq); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1115 | else if (help->help.ct_sip_info.invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1116 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1117 | return NF_ACCEPT; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1118 | } |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1119 | |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1120 | static int process_invite_request(struct sk_buff *skb, unsigned int dataoff, |
| 1121 | const char **dptr, unsigned int *datalen, |
| 1122 | unsigned int cseq) |
| 1123 | { |
| 1124 | enum ip_conntrack_info ctinfo; |
| 1125 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1126 | struct nf_conn_help *help = nfct_help(ct); |
| 1127 | unsigned int ret; |
| 1128 | |
| 1129 | flush_expectations(ct, true); |
| 1130 | ret = process_sdp(skb, dataoff, dptr, datalen, cseq); |
| 1131 | if (ret == NF_ACCEPT) |
| 1132 | help->help.ct_sip_info.invite_cseq = cseq; |
| 1133 | return ret; |
| 1134 | } |
| 1135 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1136 | static int process_bye_request(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1137 | const char **dptr, unsigned int *datalen, |
| 1138 | unsigned int cseq) |
| 1139 | { |
| 1140 | enum ip_conntrack_info ctinfo; |
| 1141 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1142 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1143 | flush_expectations(ct, true); |
| 1144 | return NF_ACCEPT; |
| 1145 | } |
| 1146 | |
| 1147 | /* Parse a REGISTER request and create a permanent expectation for incoming |
| 1148 | * signalling connections. The expectation is marked inactive and is activated |
| 1149 | * when receiving a response indicating success from the registrar. |
| 1150 | */ |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1151 | static int process_register_request(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1152 | const char **dptr, unsigned int *datalen, |
| 1153 | unsigned int cseq) |
| 1154 | { |
| 1155 | enum ip_conntrack_info ctinfo; |
| 1156 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1157 | struct nf_conn_help *help = nfct_help(ct); |
| 1158 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1159 | unsigned int matchoff, matchlen; |
| 1160 | struct nf_conntrack_expect *exp; |
| 1161 | union nf_inet_addr *saddr, daddr; |
| 1162 | __be16 port; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1163 | u8 proto; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1164 | unsigned int expires = 0; |
| 1165 | int ret; |
| 1166 | typeof(nf_nat_sip_expect_hook) nf_nat_sip_expect; |
| 1167 | |
| 1168 | /* Expected connections can not register again. */ |
| 1169 | if (ct->status & IPS_EXPECTED) |
| 1170 | return NF_ACCEPT; |
| 1171 | |
| 1172 | /* We must check the expiration time: a value of zero signals the |
| 1173 | * registrar to release the binding. We'll remove our expectation |
| 1174 | * when receiving the new bindings in the response, but we don't |
| 1175 | * want to create new ones. |
| 1176 | * |
| 1177 | * The expiration time may be contained in Expires: header, the |
| 1178 | * Contact: header parameters or the URI parameters. |
| 1179 | */ |
| 1180 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, |
| 1181 | &matchoff, &matchlen) > 0) |
| 1182 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1183 | |
| 1184 | ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, |
| 1185 | SIP_HDR_CONTACT, NULL, |
| 1186 | &matchoff, &matchlen, &daddr, &port); |
| 1187 | if (ret < 0) |
| 1188 | return NF_DROP; |
| 1189 | else if (ret == 0) |
| 1190 | return NF_ACCEPT; |
| 1191 | |
| 1192 | /* We don't support third-party registrations */ |
| 1193 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr)) |
| 1194 | return NF_ACCEPT; |
| 1195 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1196 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, *datalen, |
| 1197 | &proto) == 0) |
| 1198 | return NF_ACCEPT; |
| 1199 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1200 | if (ct_sip_parse_numerical_param(ct, *dptr, |
| 1201 | matchoff + matchlen, *datalen, |
| 1202 | "expires=", NULL, NULL, &expires) < 0) |
| 1203 | return NF_DROP; |
| 1204 | |
| 1205 | if (expires == 0) { |
| 1206 | ret = NF_ACCEPT; |
| 1207 | goto store_cseq; |
| 1208 | } |
| 1209 | |
| 1210 | exp = nf_ct_expect_alloc(ct); |
| 1211 | if (!exp) |
| 1212 | return NF_DROP; |
| 1213 | |
| 1214 | saddr = NULL; |
| 1215 | if (sip_direct_signalling) |
| 1216 | saddr = &ct->tuplehash[!dir].tuple.src.u3; |
| 1217 | |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 1218 | nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct), |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1219 | saddr, &daddr, proto, NULL, &port); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1220 | exp->timeout.expires = sip_timeout * HZ; |
| 1221 | exp->helper = nfct_help(ct)->helper; |
| 1222 | exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE; |
| 1223 | |
| 1224 | nf_nat_sip_expect = rcu_dereference(nf_nat_sip_expect_hook); |
| 1225 | if (nf_nat_sip_expect && ct->status & IPS_NAT_MASK) |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1226 | ret = nf_nat_sip_expect(skb, dataoff, dptr, datalen, exp, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1227 | matchoff, matchlen); |
| 1228 | else { |
| 1229 | if (nf_ct_expect_related(exp) != 0) |
| 1230 | ret = NF_DROP; |
| 1231 | else |
| 1232 | ret = NF_ACCEPT; |
| 1233 | } |
| 1234 | nf_ct_expect_put(exp); |
| 1235 | |
| 1236 | store_cseq: |
| 1237 | if (ret == NF_ACCEPT) |
| 1238 | help->help.ct_sip_info.register_cseq = cseq; |
| 1239 | return ret; |
| 1240 | } |
| 1241 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1242 | static int process_register_response(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1243 | const char **dptr, unsigned int *datalen, |
| 1244 | unsigned int cseq, unsigned int code) |
| 1245 | { |
| 1246 | enum ip_conntrack_info ctinfo; |
| 1247 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1248 | struct nf_conn_help *help = nfct_help(ct); |
| 1249 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 1250 | union nf_inet_addr addr; |
| 1251 | __be16 port; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1252 | u8 proto; |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1253 | unsigned int matchoff, matchlen, coff = 0; |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1254 | unsigned int expires = 0; |
| 1255 | int in_contact = 0, ret; |
| 1256 | |
| 1257 | /* According to RFC 3261, "UAs MUST NOT send a new registration until |
| 1258 | * they have received a final response from the registrar for the |
| 1259 | * previous one or the previous REGISTER request has timed out". |
| 1260 | * |
| 1261 | * However, some servers fail to detect retransmissions and send late |
| 1262 | * responses, so we store the sequence number of the last valid |
| 1263 | * request and compare it here. |
| 1264 | */ |
| 1265 | if (help->help.ct_sip_info.register_cseq != cseq) |
| 1266 | return NF_ACCEPT; |
| 1267 | |
| 1268 | if (code >= 100 && code <= 199) |
| 1269 | return NF_ACCEPT; |
| 1270 | if (code < 200 || code > 299) |
| 1271 | goto flush; |
| 1272 | |
| 1273 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, |
| 1274 | &matchoff, &matchlen) > 0) |
| 1275 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1276 | |
| 1277 | while (1) { |
| 1278 | unsigned int c_expires = expires; |
| 1279 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1280 | ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1281 | SIP_HDR_CONTACT, &in_contact, |
| 1282 | &matchoff, &matchlen, |
| 1283 | &addr, &port); |
| 1284 | if (ret < 0) |
| 1285 | return NF_DROP; |
| 1286 | else if (ret == 0) |
| 1287 | break; |
| 1288 | |
| 1289 | /* We don't support third-party registrations */ |
| 1290 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr)) |
| 1291 | continue; |
| 1292 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1293 | if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, |
| 1294 | *datalen, &proto) == 0) |
| 1295 | continue; |
| 1296 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1297 | ret = ct_sip_parse_numerical_param(ct, *dptr, |
| 1298 | matchoff + matchlen, |
| 1299 | *datalen, "expires=", |
| 1300 | NULL, NULL, &c_expires); |
| 1301 | if (ret < 0) |
| 1302 | return NF_DROP; |
| 1303 | if (c_expires == 0) |
| 1304 | break; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1305 | if (refresh_signalling_expectation(ct, &addr, proto, port, |
| 1306 | c_expires)) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1307 | return NF_ACCEPT; |
| 1308 | } |
| 1309 | |
| 1310 | flush: |
| 1311 | flush_expectations(ct, false); |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1312 | return NF_ACCEPT; |
| 1313 | } |
| 1314 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1315 | static const struct sip_handler sip_handlers[] = { |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1316 | SIP_HANDLER("INVITE", process_invite_request, process_invite_response), |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1317 | SIP_HANDLER("UPDATE", process_sdp, process_update_response), |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1318 | SIP_HANDLER("ACK", process_sdp, NULL), |
| 1319 | SIP_HANDLER("PRACK", process_sdp, process_prack_response), |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1320 | SIP_HANDLER("BYE", process_bye_request, NULL), |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1321 | SIP_HANDLER("REGISTER", process_register_request, process_register_response), |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1322 | }; |
| 1323 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1324 | static int process_sip_response(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1325 | const char **dptr, unsigned int *datalen) |
| 1326 | { |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1327 | enum ip_conntrack_info ctinfo; |
| 1328 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1329 | unsigned int matchoff, matchlen, matchend; |
| 1330 | unsigned int code, cseq, i; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1331 | |
| 1332 | if (*datalen < strlen("SIP/2.0 200")) |
| 1333 | return NF_ACCEPT; |
| 1334 | code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10); |
| 1335 | if (!code) |
| 1336 | return NF_DROP; |
| 1337 | |
| 1338 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, |
| 1339 | &matchoff, &matchlen) <= 0) |
| 1340 | return NF_DROP; |
| 1341 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1342 | if (!cseq) |
| 1343 | return NF_DROP; |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1344 | matchend = matchoff + matchlen + 1; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1345 | |
| 1346 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { |
Alexey Dobriyan | 66bf791 | 2008-09-07 18:19:25 -0700 | [diff] [blame] | 1347 | const struct sip_handler *handler; |
| 1348 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1349 | handler = &sip_handlers[i]; |
| 1350 | if (handler->response == NULL) |
| 1351 | continue; |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1352 | if (*datalen < matchend + handler->len || |
| 1353 | strnicmp(*dptr + matchend, handler->method, handler->len)) |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1354 | continue; |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1355 | return handler->response(skb, dataoff, dptr, datalen, |
| 1356 | cseq, code); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1357 | } |
| 1358 | return NF_ACCEPT; |
| 1359 | } |
| 1360 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1361 | static int process_sip_request(struct sk_buff *skb, unsigned int dataoff, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1362 | const char **dptr, unsigned int *datalen) |
| 1363 | { |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1364 | enum ip_conntrack_info ctinfo; |
| 1365 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1366 | unsigned int matchoff, matchlen; |
| 1367 | unsigned int cseq, i; |
| 1368 | |
| 1369 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { |
Alexey Dobriyan | 66bf791 | 2008-09-07 18:19:25 -0700 | [diff] [blame] | 1370 | const struct sip_handler *handler; |
| 1371 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1372 | handler = &sip_handlers[i]; |
| 1373 | if (handler->request == NULL) |
| 1374 | continue; |
| 1375 | if (*datalen < handler->len || |
| 1376 | strnicmp(*dptr, handler->method, handler->len)) |
| 1377 | continue; |
| 1378 | |
| 1379 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, |
| 1380 | &matchoff, &matchlen) <= 0) |
| 1381 | return NF_DROP; |
| 1382 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1383 | if (!cseq) |
| 1384 | return NF_DROP; |
| 1385 | |
Patrick McHardy | 3b6b9fa | 2010-02-11 12:23:53 +0100 | [diff] [blame] | 1386 | return handler->request(skb, dataoff, dptr, datalen, cseq); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1387 | } |
| 1388 | return NF_ACCEPT; |
| 1389 | } |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1390 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1391 | static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct, |
| 1392 | unsigned int dataoff, const char **dptr, |
| 1393 | unsigned int *datalen) |
| 1394 | { |
| 1395 | typeof(nf_nat_sip_hook) nf_nat_sip; |
| 1396 | int ret; |
| 1397 | |
| 1398 | if (strnicmp(*dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0) |
| 1399 | ret = process_sip_request(skb, dataoff, dptr, datalen); |
| 1400 | else |
| 1401 | ret = process_sip_response(skb, dataoff, dptr, datalen); |
| 1402 | |
| 1403 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
| 1404 | nf_nat_sip = rcu_dereference(nf_nat_sip_hook); |
| 1405 | if (nf_nat_sip && !nf_nat_sip(skb, dataoff, dptr, datalen)) |
| 1406 | ret = NF_DROP; |
| 1407 | } |
| 1408 | |
| 1409 | return ret; |
| 1410 | } |
| 1411 | |
| 1412 | static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff, |
| 1413 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
| 1414 | { |
| 1415 | struct tcphdr *th, _tcph; |
| 1416 | unsigned int dataoff, datalen; |
| 1417 | unsigned int matchoff, matchlen, clen; |
| 1418 | unsigned int msglen, origlen; |
| 1419 | const char *dptr, *end; |
| 1420 | s16 diff, tdiff = 0; |
Simon Horman | 7874896 | 2010-09-21 21:17:30 +0000 | [diff] [blame] | 1421 | int ret = NF_ACCEPT; |
Patrick McHardy | 48f8ac2 | 2010-02-11 12:29:38 +0100 | [diff] [blame] | 1422 | typeof(nf_nat_sip_seq_adjust_hook) nf_nat_sip_seq_adjust; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1423 | |
| 1424 | if (ctinfo != IP_CT_ESTABLISHED && |
| 1425 | ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) |
| 1426 | return NF_ACCEPT; |
| 1427 | |
| 1428 | /* No Data ? */ |
| 1429 | th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
| 1430 | if (th == NULL) |
| 1431 | return NF_ACCEPT; |
| 1432 | dataoff = protoff + th->doff * 4; |
| 1433 | if (dataoff >= skb->len) |
| 1434 | return NF_ACCEPT; |
| 1435 | |
| 1436 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
| 1437 | |
Patrick McHardy | a1d7c1b | 2010-05-14 21:18:17 +0200 | [diff] [blame] | 1438 | if (unlikely(skb_linearize(skb))) |
| 1439 | return NF_DROP; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1440 | |
| 1441 | dptr = skb->data + dataoff; |
| 1442 | datalen = skb->len - dataoff; |
| 1443 | if (datalen < strlen("SIP/2.0 200")) |
| 1444 | return NF_ACCEPT; |
| 1445 | |
| 1446 | while (1) { |
| 1447 | if (ct_sip_get_header(ct, dptr, 0, datalen, |
| 1448 | SIP_HDR_CONTENT_LENGTH, |
| 1449 | &matchoff, &matchlen) <= 0) |
| 1450 | break; |
| 1451 | |
| 1452 | clen = simple_strtoul(dptr + matchoff, (char **)&end, 10); |
| 1453 | if (dptr + matchoff == end) |
| 1454 | break; |
| 1455 | |
| 1456 | if (end + strlen("\r\n\r\n") > dptr + datalen) |
| 1457 | break; |
| 1458 | if (end[0] != '\r' || end[1] != '\n' || |
| 1459 | end[2] != '\r' || end[3] != '\n') |
| 1460 | break; |
| 1461 | end += strlen("\r\n\r\n") + clen; |
| 1462 | |
| 1463 | msglen = origlen = end - dptr; |
| 1464 | |
| 1465 | ret = process_sip_msg(skb, ct, dataoff, &dptr, &msglen); |
| 1466 | if (ret != NF_ACCEPT) |
| 1467 | break; |
| 1468 | diff = msglen - origlen; |
| 1469 | tdiff += diff; |
| 1470 | |
| 1471 | dataoff += msglen; |
| 1472 | dptr += msglen; |
| 1473 | datalen = datalen + diff - msglen; |
| 1474 | } |
| 1475 | |
Patrick McHardy | 48f8ac2 | 2010-02-11 12:29:38 +0100 | [diff] [blame] | 1476 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
| 1477 | nf_nat_sip_seq_adjust = rcu_dereference(nf_nat_sip_seq_adjust_hook); |
| 1478 | if (nf_nat_sip_seq_adjust) |
| 1479 | nf_nat_sip_seq_adjust(skb, tdiff); |
| 1480 | } |
| 1481 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1482 | return ret; |
| 1483 | } |
| 1484 | |
| 1485 | static int sip_help_udp(struct sk_buff *skb, unsigned int protoff, |
| 1486 | struct nf_conn *ct, enum ip_conntrack_info ctinfo) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1487 | { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1488 | unsigned int dataoff, datalen; |
| 1489 | const char *dptr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1490 | |
| 1491 | /* No Data ? */ |
| 1492 | dataoff = protoff + sizeof(struct udphdr); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1493 | if (dataoff >= skb->len) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1494 | return NF_ACCEPT; |
| 1495 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1496 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1497 | |
Patrick McHardy | a1d7c1b | 2010-05-14 21:18:17 +0200 | [diff] [blame] | 1498 | if (unlikely(skb_linearize(skb))) |
| 1499 | return NF_DROP; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1500 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1501 | dptr = skb->data + dataoff; |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1502 | datalen = skb->len - dataoff; |
Patrick McHardy | 779382e | 2008-03-25 20:17:36 -0700 | [diff] [blame] | 1503 | if (datalen < strlen("SIP/2.0 200")) |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1504 | return NF_ACCEPT; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1505 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1506 | return process_sip_msg(skb, ct, dataoff, &dptr, &datalen); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1507 | } |
| 1508 | |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1509 | static struct nf_conntrack_helper sip[MAX_PORTS][4] __read_mostly; |
| 1510 | static char sip_names[MAX_PORTS][4][sizeof("sip-65535")] __read_mostly; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1511 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1512 | static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { |
| 1513 | [SIP_EXPECT_SIGNALLING] = { |
Patrick McHardy | b87921b | 2010-02-11 12:22:48 +0100 | [diff] [blame] | 1514 | .name = "signalling", |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1515 | .max_expected = 1, |
| 1516 | .timeout = 3 * 60, |
| 1517 | }, |
| 1518 | [SIP_EXPECT_AUDIO] = { |
Patrick McHardy | b87921b | 2010-02-11 12:22:48 +0100 | [diff] [blame] | 1519 | .name = "audio", |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 1520 | .max_expected = 2 * IP_CT_DIR_MAX, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1521 | .timeout = 3 * 60, |
| 1522 | }, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1523 | [SIP_EXPECT_VIDEO] = { |
Patrick McHardy | b87921b | 2010-02-11 12:22:48 +0100 | [diff] [blame] | 1524 | .name = "video", |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1525 | .max_expected = 2 * IP_CT_DIR_MAX, |
| 1526 | .timeout = 3 * 60, |
| 1527 | }, |
Patrick McHardy | 9d288df | 2010-02-11 12:30:21 +0100 | [diff] [blame] | 1528 | [SIP_EXPECT_IMAGE] = { |
| 1529 | .name = "image", |
| 1530 | .max_expected = IP_CT_DIR_MAX, |
| 1531 | .timeout = 3 * 60, |
| 1532 | }, |
Patrick McHardy | 6002f26 | 2008-03-25 20:09:15 -0700 | [diff] [blame] | 1533 | }; |
| 1534 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1535 | static void nf_conntrack_sip_fini(void) |
| 1536 | { |
| 1537 | int i, j; |
| 1538 | |
| 1539 | for (i = 0; i < ports_c; i++) { |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1540 | for (j = 0; j < ARRAY_SIZE(sip[i]); j++) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1541 | if (sip[i][j].me == NULL) |
| 1542 | continue; |
| 1543 | nf_conntrack_helper_unregister(&sip[i][j]); |
| 1544 | } |
| 1545 | } |
| 1546 | } |
| 1547 | |
| 1548 | static int __init nf_conntrack_sip_init(void) |
| 1549 | { |
| 1550 | int i, j, ret; |
| 1551 | char *tmpname; |
| 1552 | |
| 1553 | if (ports_c == 0) |
| 1554 | ports[ports_c++] = SIP_PORT; |
| 1555 | |
| 1556 | for (i = 0; i < ports_c; i++) { |
| 1557 | memset(&sip[i], 0, sizeof(sip[i])); |
| 1558 | |
| 1559 | sip[i][0].tuple.src.l3num = AF_INET; |
Patrick McHardy | f5b321b | 2010-02-11 12:26:19 +0100 | [diff] [blame] | 1560 | sip[i][0].tuple.dst.protonum = IPPROTO_UDP; |
| 1561 | sip[i][0].help = sip_help_udp; |
| 1562 | sip[i][1].tuple.src.l3num = AF_INET; |
| 1563 | sip[i][1].tuple.dst.protonum = IPPROTO_TCP; |
| 1564 | sip[i][1].help = sip_help_tcp; |
| 1565 | |
| 1566 | sip[i][2].tuple.src.l3num = AF_INET6; |
| 1567 | sip[i][2].tuple.dst.protonum = IPPROTO_UDP; |
| 1568 | sip[i][2].help = sip_help_udp; |
| 1569 | sip[i][3].tuple.src.l3num = AF_INET6; |
| 1570 | sip[i][3].tuple.dst.protonum = IPPROTO_TCP; |
| 1571 | sip[i][3].help = sip_help_tcp; |
| 1572 | |
| 1573 | for (j = 0; j < ARRAY_SIZE(sip[i]); j++) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1574 | sip[i][j].tuple.src.u.udp.port = htons(ports[i]); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1575 | sip[i][j].expect_policy = sip_exp_policy; |
| 1576 | sip[i][j].expect_class_max = SIP_EXPECT_MAX; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1577 | sip[i][j].me = THIS_MODULE; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1578 | |
| 1579 | tmpname = &sip_names[i][j][0]; |
| 1580 | if (ports[i] == SIP_PORT) |
| 1581 | sprintf(tmpname, "sip"); |
| 1582 | else |
| 1583 | sprintf(tmpname, "sip-%u", i); |
| 1584 | sip[i][j].name = tmpname; |
| 1585 | |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 1586 | pr_debug("port #%u: %u\n", i, ports[i]); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1587 | |
| 1588 | ret = nf_conntrack_helper_register(&sip[i][j]); |
| 1589 | if (ret) { |
Stephen Hemminger | 654d0fb | 2010-05-13 15:02:08 +0200 | [diff] [blame] | 1590 | printk(KERN_ERR "nf_ct_sip: failed to register" |
| 1591 | " helper for pf: %u port: %u\n", |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1592 | sip[i][j].tuple.src.l3num, ports[i]); |
| 1593 | nf_conntrack_sip_fini(); |
| 1594 | return ret; |
| 1595 | } |
| 1596 | } |
| 1597 | } |
| 1598 | return 0; |
| 1599 | } |
| 1600 | |
| 1601 | module_init(nf_conntrack_sip_init); |
| 1602 | module_exit(nf_conntrack_sip_fini); |