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> |
Yasuyuki Kozakai | 1863f09 | 2006-12-02 22:12:54 -0800 | [diff] [blame] | 19 | #include <linux/netfilter.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 20 | |
| 21 | #include <net/netfilter/nf_conntrack.h> |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 22 | #include <net/netfilter/nf_conntrack_core.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 23 | #include <net/netfilter/nf_conntrack_expect.h> |
| 24 | #include <net/netfilter/nf_conntrack_helper.h> |
| 25 | #include <linux/netfilter/nf_conntrack_sip.h> |
| 26 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 27 | MODULE_LICENSE("GPL"); |
| 28 | MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>"); |
| 29 | MODULE_DESCRIPTION("SIP connection tracking helper"); |
| 30 | MODULE_ALIAS("ip_conntrack_sip"); |
| 31 | |
| 32 | #define MAX_PORTS 8 |
| 33 | static unsigned short ports[MAX_PORTS]; |
Stephen Hemminger | 2f0d2f1 | 2008-01-31 04:08:10 -0800 | [diff] [blame] | 34 | static unsigned int ports_c; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 35 | module_param_array(ports, ushort, &ports_c, 0400); |
| 36 | MODULE_PARM_DESC(ports, "port numbers of SIP servers"); |
| 37 | |
| 38 | static unsigned int sip_timeout __read_mostly = SIP_TIMEOUT; |
| 39 | module_param(sip_timeout, uint, 0600); |
| 40 | MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session"); |
| 41 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 42 | static int sip_direct_signalling __read_mostly = 1; |
| 43 | module_param(sip_direct_signalling, int, 0600); |
| 44 | MODULE_PARM_DESC(sip_direct_signalling, "expect incoming calls from registrar " |
| 45 | "only (default 1)"); |
| 46 | |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 47 | static int sip_direct_media __read_mostly = 1; |
| 48 | module_param(sip_direct_media, int, 0600); |
| 49 | MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling " |
| 50 | "endpoints only (default 1)"); |
| 51 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 52 | unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, |
Patrick McHardy | 2a6cfb2 | 2008-03-25 20:16:54 -0700 | [diff] [blame] | 53 | const char **dptr, |
| 54 | unsigned int *datalen) __read_mostly; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 55 | EXPORT_SYMBOL_GPL(nf_nat_sip_hook); |
| 56 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 57 | unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb, |
| 58 | const char **dptr, |
| 59 | unsigned int *datalen, |
| 60 | struct nf_conntrack_expect *exp, |
| 61 | unsigned int matchoff, |
| 62 | unsigned int matchlen) __read_mostly; |
| 63 | EXPORT_SYMBOL_GPL(nf_nat_sip_expect_hook); |
| 64 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 65 | unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb, |
| 66 | const char **dptr, |
| 67 | unsigned int dataoff, |
| 68 | unsigned int *datalen, |
| 69 | enum sdp_header_types type, |
| 70 | enum sdp_header_types term, |
| 71 | const union nf_inet_addr *addr) |
| 72 | __read_mostly; |
| 73 | EXPORT_SYMBOL_GPL(nf_nat_sdp_addr_hook); |
| 74 | |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 75 | unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb, |
| 76 | const char **dptr, |
| 77 | unsigned int *datalen, |
| 78 | unsigned int matchoff, |
| 79 | unsigned int matchlen, |
| 80 | u_int16_t port) __read_mostly; |
| 81 | EXPORT_SYMBOL_GPL(nf_nat_sdp_port_hook); |
| 82 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 83 | unsigned int (*nf_nat_sdp_session_hook)(struct sk_buff *skb, |
| 84 | const char **dptr, |
| 85 | unsigned int dataoff, |
| 86 | unsigned int *datalen, |
| 87 | const union nf_inet_addr *addr) |
| 88 | __read_mostly; |
| 89 | EXPORT_SYMBOL_GPL(nf_nat_sdp_session_hook); |
| 90 | |
| 91 | unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb, |
| 92 | const char **dptr, |
| 93 | unsigned int *datalen, |
| 94 | struct nf_conntrack_expect *rtp_exp, |
| 95 | struct nf_conntrack_expect *rtcp_exp, |
| 96 | unsigned int mediaoff, |
| 97 | unsigned int medialen, |
| 98 | union nf_inet_addr *rtp_addr) |
| 99 | __read_mostly; |
| 100 | EXPORT_SYMBOL_GPL(nf_nat_sdp_media_hook); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 101 | |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 102 | static int string_len(const struct nf_conn *ct, const char *dptr, |
| 103 | const char *limit, int *shift) |
| 104 | { |
| 105 | int len = 0; |
| 106 | |
| 107 | while (dptr < limit && isalpha(*dptr)) { |
| 108 | dptr++; |
| 109 | len++; |
| 110 | } |
| 111 | return len; |
| 112 | } |
| 113 | |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 114 | static int digits_len(const struct nf_conn *ct, const char *dptr, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 115 | const char *limit, int *shift) |
| 116 | { |
| 117 | int len = 0; |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 118 | while (dptr < limit && isdigit(*dptr)) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 119 | dptr++; |
| 120 | len++; |
| 121 | } |
| 122 | return len; |
| 123 | } |
| 124 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 125 | /* get media type + port length */ |
| 126 | static int media_len(const struct nf_conn *ct, const char *dptr, |
| 127 | const char *limit, int *shift) |
| 128 | { |
| 129 | int len = string_len(ct, dptr, limit, shift); |
| 130 | |
| 131 | dptr += len; |
| 132 | if (dptr >= limit || *dptr != ' ') |
| 133 | return 0; |
| 134 | len++; |
| 135 | dptr++; |
| 136 | |
| 137 | return len + digits_len(ct, dptr, limit, shift); |
| 138 | } |
| 139 | |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 140 | static int parse_addr(const struct nf_conn *ct, const char *cp, |
| 141 | const char **endp, union nf_inet_addr *addr, |
| 142 | const char *limit) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 143 | { |
| 144 | const char *end; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 145 | int ret = 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); |
| 151 | break; |
| 152 | case AF_INET6: |
| 153 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
| 154 | break; |
| 155 | default: |
| 156 | BUG(); |
| 157 | } |
| 158 | |
| 159 | if (ret == 0 || end == cp) |
| 160 | return 0; |
| 161 | if (endp) |
| 162 | *endp = end; |
| 163 | return 1; |
| 164 | } |
| 165 | |
| 166 | /* skip ip address. returns its length. */ |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 167 | static int epaddr_len(const struct nf_conn *ct, const char *dptr, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 168 | const char *limit, int *shift) |
| 169 | { |
Jan Engelhardt | 643a2c1 | 2007-12-17 22:43:50 -0800 | [diff] [blame] | 170 | union nf_inet_addr addr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 171 | const char *aux = dptr; |
| 172 | |
| 173 | if (!parse_addr(ct, dptr, &dptr, &addr, limit)) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 174 | pr_debug("ip: %s parse failed.!\n", dptr); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | /* Port number */ |
| 179 | if (*dptr == ':') { |
| 180 | dptr++; |
| 181 | dptr += digits_len(ct, dptr, limit, shift); |
| 182 | } |
| 183 | return dptr - aux; |
| 184 | } |
| 185 | |
| 186 | /* get address length, skiping user info. */ |
Jan Engelhardt | 13f7d63 | 2008-01-31 04:50:25 -0800 | [diff] [blame] | 187 | 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] | 188 | const char *limit, int *shift) |
| 189 | { |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 190 | const char *start = dptr; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 191 | int s = *shift; |
| 192 | |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 193 | /* Search for @, but stop at the end of the line. |
| 194 | * We are inside a sip: URI, so we don't need to worry about |
| 195 | * continuation lines. */ |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 196 | while (dptr < limit && |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 197 | *dptr != '@' && *dptr != '\r' && *dptr != '\n') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 198 | (*shift)++; |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 199 | dptr++; |
| 200 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 201 | |
Patrick McHardy | b1ec488 | 2008-03-25 20:10:11 -0700 | [diff] [blame] | 202 | if (dptr < limit && *dptr == '@') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 203 | dptr++; |
| 204 | (*shift)++; |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 205 | } else { |
| 206 | dptr = start; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 207 | *shift = s; |
Patrick McHardy | aa584ed | 2007-08-14 13:14:35 -0700 | [diff] [blame] | 208 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 209 | |
| 210 | return epaddr_len(ct, dptr, limit, shift); |
| 211 | } |
| 212 | |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 213 | /* Parse a SIP request line of the form: |
| 214 | * |
| 215 | * Request-Line = Method SP Request-URI SP SIP-Version CRLF |
| 216 | * |
| 217 | * and return the offset and length of the address contained in the Request-URI. |
| 218 | */ |
| 219 | int ct_sip_parse_request(const struct nf_conn *ct, |
| 220 | const char *dptr, unsigned int datalen, |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 221 | unsigned int *matchoff, unsigned int *matchlen, |
| 222 | union nf_inet_addr *addr, __be16 *port) |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 223 | { |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 224 | const char *start = dptr, *limit = dptr + datalen, *end; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 225 | unsigned int mlen; |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 226 | unsigned int p; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 227 | int shift = 0; |
| 228 | |
| 229 | /* Skip method and following whitespace */ |
| 230 | mlen = string_len(ct, dptr, limit, NULL); |
| 231 | if (!mlen) |
| 232 | return 0; |
| 233 | dptr += mlen; |
| 234 | if (++dptr >= limit) |
| 235 | return 0; |
| 236 | |
| 237 | /* Find SIP URI */ |
| 238 | limit -= strlen("sip:"); |
| 239 | for (; dptr < limit; dptr++) { |
| 240 | if (*dptr == '\r' || *dptr == '\n') |
| 241 | return -1; |
| 242 | if (strnicmp(dptr, "sip:", strlen("sip:")) == 0) |
| 243 | break; |
| 244 | } |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 245 | if (!skp_epaddr_len(ct, dptr, limit, &shift)) |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 246 | return 0; |
Patrick McHardy | 624f8b7 | 2008-03-25 20:19:30 -0700 | [diff] [blame] | 247 | dptr += shift; |
| 248 | |
| 249 | if (!parse_addr(ct, dptr, &end, addr, limit)) |
| 250 | return -1; |
| 251 | if (end < limit && *end == ':') { |
| 252 | end++; |
| 253 | p = simple_strtoul(end, (char **)&end, 10); |
| 254 | if (p < 1024 || p > 65535) |
| 255 | return -1; |
| 256 | *port = htons(p); |
| 257 | } else |
| 258 | *port = htons(SIP_PORT); |
| 259 | |
| 260 | if (end == dptr) |
| 261 | return 0; |
| 262 | *matchoff = dptr - start; |
| 263 | *matchlen = end - dptr; |
Patrick McHardy | ac36774 | 2008-03-25 20:18:40 -0700 | [diff] [blame] | 264 | return 1; |
| 265 | } |
| 266 | EXPORT_SYMBOL_GPL(ct_sip_parse_request); |
| 267 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 268 | /* SIP header parsing: SIP headers are located at the beginning of a line, but |
| 269 | * may span several lines, in which case the continuation lines begin with a |
| 270 | * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or |
| 271 | * CRLF, RFC 3261 allows only CRLF, we support both. |
| 272 | * |
| 273 | * Headers are followed by (optionally) whitespace, a colon, again (optionally) |
| 274 | * whitespace and the values. Whitespace in this context means any amount of |
| 275 | * tabs, spaces and continuation lines, which are treated as a single whitespace |
| 276 | * character. |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 277 | * |
| 278 | * Some headers may appear multiple times. A comma seperated list of values is |
| 279 | * equivalent to multiple headers. |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 280 | */ |
| 281 | static const struct sip_header ct_sip_hdrs[] = { |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 282 | [SIP_HDR_CSEQ] = SIP_HDR("CSeq", NULL, NULL, digits_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 283 | [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len), |
| 284 | [SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len), |
| 285 | [SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len), |
| 286 | [SIP_HDR_VIA] = SIP_HDR("Via", "v", "UDP ", epaddr_len), |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 287 | [SIP_HDR_EXPIRES] = SIP_HDR("Expires", NULL, NULL, digits_len), |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 288 | [SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len), |
| 289 | }; |
| 290 | |
| 291 | static const char *sip_follow_continuation(const char *dptr, const char *limit) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 292 | { |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 293 | /* Walk past newline */ |
| 294 | if (++dptr >= limit) |
| 295 | return NULL; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 296 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 297 | /* Skip '\n' in CR LF */ |
| 298 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 299 | if (++dptr >= limit) |
| 300 | return NULL; |
| 301 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 302 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 303 | /* Continuation line? */ |
| 304 | if (*dptr != ' ' && *dptr != '\t') |
| 305 | return NULL; |
| 306 | |
| 307 | /* skip leading whitespace */ |
| 308 | for (; dptr < limit; dptr++) { |
| 309 | if (*dptr != ' ' && *dptr != '\t') |
| 310 | break; |
| 311 | } |
| 312 | return dptr; |
| 313 | } |
| 314 | |
| 315 | static const char *sip_skip_whitespace(const char *dptr, const char *limit) |
| 316 | { |
| 317 | for (; dptr < limit; dptr++) { |
| 318 | if (*dptr == ' ') |
| 319 | continue; |
| 320 | if (*dptr != '\r' && *dptr != '\n') |
| 321 | break; |
| 322 | dptr = sip_follow_continuation(dptr, limit); |
| 323 | if (dptr == NULL) |
| 324 | return NULL; |
| 325 | } |
| 326 | return dptr; |
| 327 | } |
| 328 | |
| 329 | /* Search within a SIP header value, dealing with continuation lines */ |
| 330 | static const char *ct_sip_header_search(const char *dptr, const char *limit, |
| 331 | const char *needle, unsigned int len) |
| 332 | { |
| 333 | for (limit -= len; dptr < limit; dptr++) { |
| 334 | if (*dptr == '\r' || *dptr == '\n') { |
| 335 | dptr = sip_follow_continuation(dptr, limit); |
| 336 | if (dptr == NULL) |
| 337 | break; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 338 | continue; |
| 339 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 340 | |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 341 | if (strnicmp(dptr, needle, len) == 0) |
| 342 | return dptr; |
| 343 | } |
| 344 | return NULL; |
| 345 | } |
| 346 | |
| 347 | int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, |
| 348 | unsigned int dataoff, unsigned int datalen, |
| 349 | enum sip_header_types type, |
| 350 | unsigned int *matchoff, unsigned int *matchlen) |
| 351 | { |
| 352 | const struct sip_header *hdr = &ct_sip_hdrs[type]; |
| 353 | const char *start = dptr, *limit = dptr + datalen; |
| 354 | int shift = 0; |
| 355 | |
| 356 | for (dptr += dataoff; dptr < limit; dptr++) { |
| 357 | /* Find beginning of line */ |
| 358 | if (*dptr != '\r' && *dptr != '\n') |
| 359 | continue; |
| 360 | if (++dptr >= limit) |
| 361 | break; |
| 362 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 363 | if (++dptr >= limit) |
| 364 | break; |
| 365 | } |
| 366 | |
| 367 | /* Skip continuation lines */ |
| 368 | if (*dptr == ' ' || *dptr == '\t') |
| 369 | continue; |
| 370 | |
| 371 | /* Find header. Compact headers must be followed by a |
| 372 | * non-alphabetic character to avoid mismatches. */ |
| 373 | if (limit - dptr >= hdr->len && |
| 374 | strnicmp(dptr, hdr->name, hdr->len) == 0) |
| 375 | dptr += hdr->len; |
| 376 | else if (hdr->cname && limit - dptr >= hdr->clen + 1 && |
| 377 | strnicmp(dptr, hdr->cname, hdr->clen) == 0 && |
| 378 | !isalpha(*(dptr + hdr->clen + 1))) |
| 379 | dptr += hdr->clen; |
| 380 | else |
| 381 | continue; |
| 382 | |
| 383 | /* Find and skip colon */ |
| 384 | dptr = sip_skip_whitespace(dptr, limit); |
| 385 | if (dptr == NULL) |
| 386 | break; |
| 387 | if (*dptr != ':' || ++dptr >= limit) |
| 388 | break; |
| 389 | |
| 390 | /* Skip whitespace after colon */ |
| 391 | dptr = sip_skip_whitespace(dptr, limit); |
| 392 | if (dptr == NULL) |
| 393 | break; |
| 394 | |
| 395 | *matchoff = dptr - start; |
| 396 | if (hdr->search) { |
| 397 | dptr = ct_sip_header_search(dptr, limit, hdr->search, |
| 398 | hdr->slen); |
| 399 | if (!dptr) |
| 400 | return -1; |
| 401 | dptr += hdr->slen; |
| 402 | } |
| 403 | |
| 404 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 405 | if (!*matchlen) |
| 406 | return -1; |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 407 | *matchoff = dptr - start + shift; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 408 | return 1; |
| 409 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 410 | return 0; |
| 411 | } |
Patrick McHardy | ea45f12 | 2008-03-25 20:18:57 -0700 | [diff] [blame] | 412 | EXPORT_SYMBOL_GPL(ct_sip_get_header); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 413 | |
Patrick McHardy | 05e3ced | 2008-03-25 20:19:13 -0700 | [diff] [blame] | 414 | /* Get next header field in a list of comma seperated values */ |
| 415 | static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr, |
| 416 | unsigned int dataoff, unsigned int datalen, |
| 417 | enum sip_header_types type, |
| 418 | unsigned int *matchoff, unsigned int *matchlen) |
| 419 | { |
| 420 | const struct sip_header *hdr = &ct_sip_hdrs[type]; |
| 421 | const char *start = dptr, *limit = dptr + datalen; |
| 422 | int shift = 0; |
| 423 | |
| 424 | dptr += dataoff; |
| 425 | |
| 426 | dptr = ct_sip_header_search(dptr, limit, ",", strlen(",")); |
| 427 | if (!dptr) |
| 428 | return 0; |
| 429 | |
| 430 | dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen); |
| 431 | if (!dptr) |
| 432 | return 0; |
| 433 | dptr += hdr->slen; |
| 434 | |
| 435 | *matchoff = dptr - start; |
| 436 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
| 437 | if (!*matchlen) |
| 438 | return -1; |
| 439 | *matchoff += shift; |
| 440 | return 1; |
| 441 | } |
| 442 | |
| 443 | /* Walk through headers until a parsable one is found or no header of the |
| 444 | * given type is left. */ |
| 445 | static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, |
| 446 | unsigned int dataoff, unsigned int datalen, |
| 447 | enum sip_header_types type, int *in_header, |
| 448 | unsigned int *matchoff, unsigned int *matchlen) |
| 449 | { |
| 450 | int ret; |
| 451 | |
| 452 | if (in_header && *in_header) { |
| 453 | while (1) { |
| 454 | ret = ct_sip_next_header(ct, dptr, dataoff, datalen, |
| 455 | type, matchoff, matchlen); |
| 456 | if (ret > 0) |
| 457 | return ret; |
| 458 | if (ret == 0) |
| 459 | break; |
| 460 | dataoff += *matchoff; |
| 461 | } |
| 462 | *in_header = 0; |
| 463 | } |
| 464 | |
| 465 | while (1) { |
| 466 | ret = ct_sip_get_header(ct, dptr, dataoff, datalen, |
| 467 | type, matchoff, matchlen); |
| 468 | if (ret > 0) |
| 469 | break; |
| 470 | if (ret == 0) |
| 471 | return ret; |
| 472 | dataoff += *matchoff; |
| 473 | } |
| 474 | |
| 475 | if (in_header) |
| 476 | *in_header = 1; |
| 477 | return 1; |
| 478 | } |
| 479 | |
| 480 | /* Locate a SIP header, parse the URI and return the offset and length of |
| 481 | * the address as well as the address and port themselves. A stream of |
| 482 | * headers can be parsed by handing in a non-NULL datalen and in_header |
| 483 | * pointer. |
| 484 | */ |
| 485 | int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, |
| 486 | unsigned int *dataoff, unsigned int datalen, |
| 487 | enum sip_header_types type, int *in_header, |
| 488 | unsigned int *matchoff, unsigned int *matchlen, |
| 489 | union nf_inet_addr *addr, __be16 *port) |
| 490 | { |
| 491 | const char *c, *limit = dptr + datalen; |
| 492 | unsigned int p; |
| 493 | int ret; |
| 494 | |
| 495 | ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen, |
| 496 | type, in_header, matchoff, matchlen); |
| 497 | WARN_ON(ret < 0); |
| 498 | if (ret == 0) |
| 499 | return ret; |
| 500 | |
| 501 | if (!parse_addr(ct, dptr + *matchoff, &c, addr, limit)) |
| 502 | return -1; |
| 503 | if (*c == ':') { |
| 504 | c++; |
| 505 | p = simple_strtoul(c, (char **)&c, 10); |
| 506 | if (p < 1024 || p > 65535) |
| 507 | return -1; |
| 508 | *port = htons(p); |
| 509 | } else |
| 510 | *port = htons(SIP_PORT); |
| 511 | |
| 512 | if (dataoff) |
| 513 | *dataoff = c - dptr; |
| 514 | return 1; |
| 515 | } |
| 516 | EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri); |
| 517 | |
Patrick McHardy | 2bbb211 | 2008-03-25 20:24:24 -0700 | [diff] [blame] | 518 | /* Parse address from header parameter and return address, offset and length */ |
| 519 | int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr, |
| 520 | unsigned int dataoff, unsigned int datalen, |
| 521 | const char *name, |
| 522 | unsigned int *matchoff, unsigned int *matchlen, |
| 523 | union nf_inet_addr *addr) |
| 524 | { |
| 525 | const char *limit = dptr + datalen; |
| 526 | const char *start, *end; |
| 527 | |
| 528 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 529 | if (!limit) |
| 530 | limit = dptr + datalen; |
| 531 | |
| 532 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 533 | if (!start) |
| 534 | return 0; |
| 535 | |
| 536 | start += strlen(name); |
| 537 | if (!parse_addr(ct, start, &end, addr, limit)) |
| 538 | return 0; |
| 539 | *matchoff = start - dptr; |
| 540 | *matchlen = end - start; |
| 541 | return 1; |
| 542 | } |
| 543 | EXPORT_SYMBOL_GPL(ct_sip_parse_address_param); |
| 544 | |
| 545 | /* Parse numerical header parameter and return value, offset and length */ |
| 546 | int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr, |
| 547 | unsigned int dataoff, unsigned int datalen, |
| 548 | const char *name, |
| 549 | unsigned int *matchoff, unsigned int *matchlen, |
| 550 | unsigned int *val) |
| 551 | { |
| 552 | const char *limit = dptr + datalen; |
| 553 | const char *start; |
| 554 | char *end; |
| 555 | |
| 556 | limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(",")); |
| 557 | if (!limit) |
| 558 | limit = dptr + datalen; |
| 559 | |
| 560 | start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name)); |
| 561 | if (!start) |
| 562 | return 0; |
| 563 | |
| 564 | start += strlen(name); |
| 565 | *val = simple_strtoul(start, &end, 0); |
| 566 | if (start == end) |
| 567 | return 0; |
| 568 | if (matchoff && matchlen) { |
| 569 | *matchoff = start - dptr; |
| 570 | *matchlen = end - start; |
| 571 | } |
| 572 | return 1; |
| 573 | } |
| 574 | EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param); |
| 575 | |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 576 | /* SDP header parsing: a SDP session description contains an ordered set of |
| 577 | * headers, starting with a section containing general session parameters, |
| 578 | * optionally followed by multiple media descriptions. |
| 579 | * |
| 580 | * SDP headers always start at the beginning of a line. According to RFC 2327: |
| 581 | * "The sequence CRLF (0x0d0a) is used to end a record, although parsers should |
| 582 | * be tolerant and also accept records terminated with a single newline |
| 583 | * character". We handle both cases. |
| 584 | */ |
| 585 | static const struct sip_header ct_sdp_hdrs[] = { |
| 586 | [SDP_HDR_VERSION] = SDP_HDR("v=", NULL, digits_len), |
| 587 | [SDP_HDR_OWNER_IP4] = SDP_HDR("o=", "IN IP4 ", epaddr_len), |
| 588 | [SDP_HDR_CONNECTION_IP4] = SDP_HDR("c=", "IN IP4 ", epaddr_len), |
| 589 | [SDP_HDR_OWNER_IP6] = SDP_HDR("o=", "IN IP6 ", epaddr_len), |
| 590 | [SDP_HDR_CONNECTION_IP6] = SDP_HDR("c=", "IN IP6 ", epaddr_len), |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 591 | [SDP_HDR_MEDIA] = SDP_HDR("m=", NULL, media_len), |
Patrick McHardy | 3e9b4600b | 2008-03-25 20:17:55 -0700 | [diff] [blame] | 592 | }; |
| 593 | |
| 594 | /* Linear string search within SDP header values */ |
| 595 | static const char *ct_sdp_header_search(const char *dptr, const char *limit, |
| 596 | const char *needle, unsigned int len) |
| 597 | { |
| 598 | for (limit -= len; dptr < limit; dptr++) { |
| 599 | if (*dptr == '\r' || *dptr == '\n') |
| 600 | break; |
| 601 | if (strncmp(dptr, needle, len) == 0) |
| 602 | return dptr; |
| 603 | } |
| 604 | return NULL; |
| 605 | } |
| 606 | |
| 607 | /* Locate a SDP header (optionally a substring within the header value), |
| 608 | * optionally stopping at the first occurence of the term header, parse |
| 609 | * it and return the offset and length of the data we're interested in. |
| 610 | */ |
| 611 | int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr, |
| 612 | unsigned int dataoff, unsigned int datalen, |
| 613 | enum sdp_header_types type, |
| 614 | enum sdp_header_types term, |
| 615 | unsigned int *matchoff, unsigned int *matchlen) |
| 616 | { |
| 617 | const struct sip_header *hdr = &ct_sdp_hdrs[type]; |
| 618 | const struct sip_header *thdr = &ct_sdp_hdrs[term]; |
| 619 | const char *start = dptr, *limit = dptr + datalen; |
| 620 | int shift = 0; |
| 621 | |
| 622 | for (dptr += dataoff; dptr < limit; dptr++) { |
| 623 | /* Find beginning of line */ |
| 624 | if (*dptr != '\r' && *dptr != '\n') |
| 625 | continue; |
| 626 | if (++dptr >= limit) |
| 627 | break; |
| 628 | if (*(dptr - 1) == '\r' && *dptr == '\n') { |
| 629 | if (++dptr >= limit) |
| 630 | break; |
| 631 | } |
| 632 | |
| 633 | if (term != SDP_HDR_UNSPEC && |
| 634 | limit - dptr >= thdr->len && |
| 635 | strnicmp(dptr, thdr->name, thdr->len) == 0) |
| 636 | break; |
| 637 | else if (limit - dptr >= hdr->len && |
| 638 | strnicmp(dptr, hdr->name, hdr->len) == 0) |
| 639 | dptr += hdr->len; |
| 640 | else |
| 641 | continue; |
| 642 | |
| 643 | *matchoff = dptr - start; |
| 644 | if (hdr->search) { |
| 645 | dptr = ct_sdp_header_search(dptr, limit, hdr->search, |
| 646 | hdr->slen); |
| 647 | if (!dptr) |
| 648 | return -1; |
| 649 | dptr += hdr->slen; |
| 650 | } |
| 651 | |
| 652 | *matchlen = hdr->match_len(ct, dptr, limit, &shift); |
| 653 | if (!*matchlen) |
| 654 | return -1; |
| 655 | *matchoff = dptr - start + shift; |
| 656 | return 1; |
| 657 | } |
| 658 | return 0; |
| 659 | } |
| 660 | EXPORT_SYMBOL_GPL(ct_sip_get_sdp_header); |
| 661 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 662 | static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr, |
| 663 | unsigned int dataoff, unsigned int datalen, |
| 664 | enum sdp_header_types type, |
| 665 | enum sdp_header_types term, |
| 666 | unsigned int *matchoff, unsigned int *matchlen, |
| 667 | union nf_inet_addr *addr) |
| 668 | { |
| 669 | int ret; |
| 670 | |
| 671 | ret = ct_sip_get_sdp_header(ct, dptr, dataoff, datalen, type, term, |
| 672 | matchoff, matchlen); |
| 673 | if (ret <= 0) |
| 674 | return ret; |
| 675 | |
| 676 | if (!parse_addr(ct, dptr + *matchoff, NULL, addr, |
| 677 | dptr + *matchoff + *matchlen)) |
| 678 | return -1; |
| 679 | return 1; |
| 680 | } |
| 681 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 682 | static int refresh_signalling_expectation(struct nf_conn *ct, |
| 683 | union nf_inet_addr *addr, |
| 684 | __be16 port, |
| 685 | unsigned int expires) |
| 686 | { |
| 687 | struct nf_conn_help *help = nfct_help(ct); |
| 688 | struct nf_conntrack_expect *exp; |
| 689 | struct hlist_node *n, *next; |
| 690 | int found = 0; |
| 691 | |
| 692 | spin_lock_bh(&nf_conntrack_lock); |
| 693 | hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) { |
| 694 | if (exp->class != SIP_EXPECT_SIGNALLING || |
| 695 | !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) || |
| 696 | exp->tuple.dst.u.udp.port != port) |
| 697 | continue; |
| 698 | if (!del_timer(&exp->timeout)) |
| 699 | continue; |
| 700 | exp->flags &= ~NF_CT_EXPECT_INACTIVE; |
| 701 | exp->timeout.expires = jiffies + expires * HZ; |
| 702 | add_timer(&exp->timeout); |
| 703 | found = 1; |
| 704 | break; |
| 705 | } |
| 706 | spin_unlock_bh(&nf_conntrack_lock); |
| 707 | return found; |
| 708 | } |
| 709 | |
| 710 | static void flush_expectations(struct nf_conn *ct, bool media) |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 711 | { |
| 712 | struct nf_conn_help *help = nfct_help(ct); |
| 713 | struct nf_conntrack_expect *exp; |
| 714 | struct hlist_node *n, *next; |
| 715 | |
| 716 | spin_lock_bh(&nf_conntrack_lock); |
| 717 | hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) { |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 718 | if ((exp->class != SIP_EXPECT_SIGNALLING) ^ media) |
| 719 | continue; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 720 | if (!del_timer(&exp->timeout)) |
| 721 | continue; |
| 722 | nf_ct_unlink_expect(exp); |
| 723 | nf_ct_expect_put(exp); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 724 | if (!media) |
| 725 | break; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 726 | } |
| 727 | spin_unlock_bh(&nf_conntrack_lock); |
| 728 | } |
| 729 | |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 730 | static int set_expected_rtp_rtcp(struct sk_buff *skb, |
| 731 | const char **dptr, unsigned int *datalen, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 732 | union nf_inet_addr *daddr, __be16 port, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 733 | enum sip_expectation_classes class, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 734 | unsigned int mediaoff, unsigned int medialen) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 735 | { |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 736 | struct nf_conntrack_expect *exp, *rtp_exp, *rtcp_exp; |
Patrick McHardy | 212440a | 2008-03-25 20:17:13 -0700 | [diff] [blame] | 737 | enum ip_conntrack_info ctinfo; |
| 738 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 739 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 740 | union nf_inet_addr *saddr; |
| 741 | struct nf_conntrack_tuple tuple; |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 742 | int direct_rtp = 0, skip_expect = 0, ret = NF_DROP; |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 743 | u_int16_t base_port; |
| 744 | __be16 rtp_port, rtcp_port; |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 745 | typeof(nf_nat_sdp_port_hook) nf_nat_sdp_port; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 746 | typeof(nf_nat_sdp_media_hook) nf_nat_sdp_media; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 747 | |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 748 | saddr = NULL; |
| 749 | if (sip_direct_media) { |
| 750 | if (!nf_inet_addr_cmp(daddr, &ct->tuplehash[dir].tuple.src.u3)) |
| 751 | return NF_ACCEPT; |
| 752 | saddr = &ct->tuplehash[!dir].tuple.src.u3; |
| 753 | } |
| 754 | |
| 755 | /* We need to check whether the registration exists before attempting |
| 756 | * to register it since we can see the same media description multiple |
| 757 | * times on different connections in case multiple endpoints receive |
| 758 | * the same call. |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 759 | * |
| 760 | * RTP optimization: if we find a matching media channel expectation |
| 761 | * and both the expectation and this connection are SNATed, we assume |
| 762 | * both sides can reach each other directly and use the final |
| 763 | * destination address from the expectation. We still need to keep |
| 764 | * the NATed expectations for media that might arrive from the |
| 765 | * outside, and additionally need to expect the direct RTP stream |
| 766 | * in case it passes through us even without NAT. |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 767 | */ |
| 768 | memset(&tuple, 0, sizeof(tuple)); |
| 769 | if (saddr) |
| 770 | tuple.src.u3 = *saddr; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 771 | tuple.src.l3num = nf_ct_l3num(ct); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 772 | tuple.dst.protonum = IPPROTO_UDP; |
| 773 | tuple.dst.u3 = *daddr; |
| 774 | tuple.dst.u.udp.port = port; |
| 775 | |
| 776 | rcu_read_lock(); |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 777 | do { |
| 778 | exp = __nf_ct_expect_find(&tuple); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 779 | |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 780 | if (!exp || exp->master == ct || |
| 781 | nfct_help(exp->master)->helper != nfct_help(ct)->helper || |
| 782 | exp->class != class) |
| 783 | break; |
Patrick McHardy | e1f9a46 | 2008-04-19 17:53:52 -0700 | [diff] [blame] | 784 | #ifdef CONFIG_NF_NAT_NEEDED |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 785 | if (exp->tuple.src.l3num == AF_INET && !direct_rtp && |
| 786 | (exp->saved_ip != exp->tuple.dst.u3.ip || |
| 787 | exp->saved_proto.udp.port != exp->tuple.dst.u.udp.port) && |
| 788 | ct->status & IPS_NAT_MASK) { |
| 789 | daddr->ip = exp->saved_ip; |
| 790 | tuple.dst.u3.ip = exp->saved_ip; |
| 791 | tuple.dst.u.udp.port = exp->saved_proto.udp.port; |
| 792 | direct_rtp = 1; |
| 793 | } else |
Patrick McHardy | e1f9a46 | 2008-04-19 17:53:52 -0700 | [diff] [blame] | 794 | #endif |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 795 | skip_expect = 1; |
| 796 | } while (!skip_expect); |
| 797 | rcu_read_unlock(); |
Patrick McHardy | d901a93 | 2008-03-25 20:25:32 -0700 | [diff] [blame] | 798 | |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 799 | base_port = ntohs(tuple.dst.u.udp.port) & ~1; |
| 800 | rtp_port = htons(base_port); |
| 801 | rtcp_port = htons(base_port + 1); |
| 802 | |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 803 | if (direct_rtp) { |
| 804 | nf_nat_sdp_port = rcu_dereference(nf_nat_sdp_port_hook); |
| 805 | if (nf_nat_sdp_port && |
| 806 | !nf_nat_sdp_port(skb, dptr, datalen, |
| 807 | mediaoff, medialen, ntohs(rtp_port))) |
| 808 | goto err1; |
| 809 | } |
| 810 | |
| 811 | if (skip_expect) |
| 812 | return NF_ACCEPT; |
| 813 | |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 814 | rtp_exp = nf_ct_expect_alloc(ct); |
| 815 | if (rtp_exp == NULL) |
| 816 | goto err1; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 817 | 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] | 818 | IPPROTO_UDP, NULL, &rtp_port); |
| 819 | |
| 820 | rtcp_exp = nf_ct_expect_alloc(ct); |
| 821 | if (rtcp_exp == NULL) |
| 822 | goto err2; |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 823 | 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] | 824 | IPPROTO_UDP, NULL, &rtcp_port); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 825 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 826 | nf_nat_sdp_media = rcu_dereference(nf_nat_sdp_media_hook); |
Patrick McHardy | c7f485a | 2008-03-25 20:26:43 -0700 | [diff] [blame] | 827 | if (nf_nat_sdp_media && ct->status & IPS_NAT_MASK && !direct_rtp) |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 828 | ret = nf_nat_sdp_media(skb, dptr, datalen, rtp_exp, rtcp_exp, |
| 829 | mediaoff, medialen, daddr); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 830 | else { |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 831 | if (nf_ct_expect_related(rtp_exp) == 0) { |
| 832 | if (nf_ct_expect_related(rtcp_exp) != 0) |
| 833 | nf_ct_unexpect_related(rtp_exp); |
| 834 | else |
| 835 | ret = NF_ACCEPT; |
| 836 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 837 | } |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 838 | nf_ct_expect_put(rtcp_exp); |
| 839 | err2: |
| 840 | nf_ct_expect_put(rtp_exp); |
| 841 | err1: |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 842 | return ret; |
| 843 | } |
| 844 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 845 | static const struct sdp_media_type sdp_media_types[] = { |
| 846 | SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO), |
| 847 | SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO), |
| 848 | }; |
| 849 | |
| 850 | static const struct sdp_media_type *sdp_media_type(const char *dptr, |
| 851 | unsigned int matchoff, |
| 852 | unsigned int matchlen) |
| 853 | { |
| 854 | const struct sdp_media_type *t; |
| 855 | unsigned int i; |
| 856 | |
| 857 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); i++) { |
| 858 | t = &sdp_media_types[i]; |
| 859 | if (matchlen < t->len || |
| 860 | strncmp(dptr + matchoff, t->name, t->len)) |
| 861 | continue; |
| 862 | return t; |
| 863 | } |
| 864 | return NULL; |
| 865 | } |
| 866 | |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 867 | static int process_sdp(struct sk_buff *skb, |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 868 | const char **dptr, unsigned int *datalen, |
| 869 | unsigned int cseq) |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 870 | { |
| 871 | enum ip_conntrack_info ctinfo; |
| 872 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 873 | struct nf_conn_help *help = nfct_help(ct); |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 874 | unsigned int matchoff, matchlen; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 875 | unsigned int mediaoff, medialen; |
| 876 | unsigned int sdpoff; |
| 877 | unsigned int caddr_len, maddr_len; |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 878 | unsigned int i; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 879 | union nf_inet_addr caddr, maddr, rtp_addr; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 880 | unsigned int port; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 881 | enum sdp_header_types c_hdr; |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 882 | const struct sdp_media_type *t; |
| 883 | int ret = NF_ACCEPT; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 884 | typeof(nf_nat_sdp_addr_hook) nf_nat_sdp_addr; |
| 885 | typeof(nf_nat_sdp_session_hook) nf_nat_sdp_session; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 886 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 887 | nf_nat_sdp_addr = rcu_dereference(nf_nat_sdp_addr_hook); |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 888 | c_hdr = nf_ct_l3num(ct) == AF_INET ? SDP_HDR_CONNECTION_IP4 : |
| 889 | SDP_HDR_CONNECTION_IP6; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 890 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 891 | /* Find beginning of session description */ |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 892 | if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen, |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 893 | SDP_HDR_VERSION, SDP_HDR_UNSPEC, |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 894 | &matchoff, &matchlen) <= 0) |
| 895 | return NF_ACCEPT; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 896 | sdpoff = matchoff; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 897 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 898 | /* The connection information is contained in the session description |
| 899 | * and/or once per media description. The first media description marks |
| 900 | * the end of the session description. */ |
| 901 | caddr_len = 0; |
| 902 | if (ct_sip_parse_sdp_addr(ct, *dptr, sdpoff, *datalen, |
| 903 | c_hdr, SDP_HDR_MEDIA, |
| 904 | &matchoff, &matchlen, &caddr) > 0) |
| 905 | caddr_len = matchlen; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 906 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 907 | mediaoff = sdpoff; |
| 908 | for (i = 0; i < ARRAY_SIZE(sdp_media_types); ) { |
| 909 | if (ct_sip_get_sdp_header(ct, *dptr, mediaoff, *datalen, |
| 910 | SDP_HDR_MEDIA, SDP_HDR_UNSPEC, |
| 911 | &mediaoff, &medialen) <= 0) |
| 912 | break; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 913 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 914 | /* Get media type and port number. A media port value of zero |
| 915 | * indicates an inactive stream. */ |
| 916 | t = sdp_media_type(*dptr, mediaoff, medialen); |
| 917 | if (!t) { |
| 918 | mediaoff += medialen; |
| 919 | continue; |
| 920 | } |
| 921 | mediaoff += t->len; |
| 922 | medialen -= t->len; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 923 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 924 | port = simple_strtoul(*dptr + mediaoff, NULL, 10); |
| 925 | if (port == 0) |
| 926 | continue; |
| 927 | if (port < 1024 || port > 65535) |
| 928 | return NF_DROP; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 929 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 930 | /* The media description overrides the session description. */ |
| 931 | maddr_len = 0; |
| 932 | if (ct_sip_parse_sdp_addr(ct, *dptr, mediaoff, *datalen, |
| 933 | c_hdr, SDP_HDR_MEDIA, |
| 934 | &matchoff, &matchlen, &maddr) > 0) { |
| 935 | maddr_len = matchlen; |
| 936 | memcpy(&rtp_addr, &maddr, sizeof(rtp_addr)); |
| 937 | } else if (caddr_len) |
| 938 | memcpy(&rtp_addr, &caddr, sizeof(rtp_addr)); |
| 939 | else |
| 940 | return NF_DROP; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 941 | |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 942 | ret = set_expected_rtp_rtcp(skb, dptr, datalen, |
| 943 | &rtp_addr, htons(port), t->class, |
| 944 | mediaoff, medialen); |
| 945 | if (ret != NF_ACCEPT) |
| 946 | return ret; |
| 947 | |
| 948 | /* Update media connection address if present */ |
| 949 | if (maddr_len && nf_nat_sdp_addr && ct->status & IPS_NAT_MASK) { |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 950 | ret = nf_nat_sdp_addr(skb, dptr, mediaoff, datalen, |
| 951 | c_hdr, SDP_HDR_MEDIA, &rtp_addr); |
| 952 | if (ret != NF_ACCEPT) |
| 953 | return ret; |
| 954 | } |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 955 | i++; |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 956 | } |
| 957 | |
| 958 | /* Update session connection and owner addresses */ |
| 959 | nf_nat_sdp_session = rcu_dereference(nf_nat_sdp_session_hook); |
| 960 | if (nf_nat_sdp_session && ct->status & IPS_NAT_MASK) |
| 961 | ret = nf_nat_sdp_session(skb, dptr, sdpoff, datalen, &rtp_addr); |
| 962 | |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 963 | if (ret == NF_ACCEPT && i > 0) |
| 964 | help->help.ct_sip_info.invite_cseq = cseq; |
| 965 | |
Patrick McHardy | 4ab9e64 | 2008-03-25 20:26:08 -0700 | [diff] [blame] | 966 | return ret; |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 967 | } |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 968 | static int process_invite_response(struct sk_buff *skb, |
| 969 | const char **dptr, unsigned int *datalen, |
| 970 | unsigned int cseq, unsigned int code) |
| 971 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 972 | enum ip_conntrack_info ctinfo; |
| 973 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 974 | struct nf_conn_help *help = nfct_help(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 975 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 976 | if ((code >= 100 && code <= 199) || |
| 977 | (code >= 200 && code <= 299)) |
| 978 | return process_sdp(skb, dptr, datalen, cseq); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 979 | else if (help->help.ct_sip_info.invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 980 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 981 | return NF_ACCEPT; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 982 | } |
| 983 | |
| 984 | static int process_update_response(struct sk_buff *skb, |
| 985 | const char **dptr, unsigned int *datalen, |
| 986 | unsigned int cseq, unsigned int code) |
| 987 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 988 | enum ip_conntrack_info ctinfo; |
| 989 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 990 | struct nf_conn_help *help = nfct_help(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 991 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 992 | if ((code >= 100 && code <= 199) || |
| 993 | (code >= 200 && code <= 299)) |
| 994 | return process_sdp(skb, dptr, datalen, cseq); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 995 | else if (help->help.ct_sip_info.invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 996 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 997 | return NF_ACCEPT; |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 998 | } |
| 999 | |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1000 | static int process_prack_response(struct sk_buff *skb, |
| 1001 | const char **dptr, unsigned int *datalen, |
| 1002 | unsigned int cseq, unsigned int code) |
| 1003 | { |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1004 | enum ip_conntrack_info ctinfo; |
| 1005 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1006 | struct nf_conn_help *help = nfct_help(ct); |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1007 | |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1008 | if ((code >= 100 && code <= 199) || |
| 1009 | (code >= 200 && code <= 299)) |
| 1010 | return process_sdp(skb, dptr, datalen, cseq); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1011 | else if (help->help.ct_sip_info.invite_cseq == cseq) |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1012 | flush_expectations(ct, true); |
Patrick McHardy | ef75d49 | 2008-05-08 01:15:21 -0700 | [diff] [blame] | 1013 | return NF_ACCEPT; |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1014 | } |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1015 | |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1016 | static int process_bye_request(struct sk_buff *skb, |
| 1017 | const char **dptr, unsigned int *datalen, |
| 1018 | unsigned int cseq) |
| 1019 | { |
| 1020 | enum ip_conntrack_info ctinfo; |
| 1021 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1022 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1023 | flush_expectations(ct, true); |
| 1024 | return NF_ACCEPT; |
| 1025 | } |
| 1026 | |
| 1027 | /* Parse a REGISTER request and create a permanent expectation for incoming |
| 1028 | * signalling connections. The expectation is marked inactive and is activated |
| 1029 | * when receiving a response indicating success from the registrar. |
| 1030 | */ |
| 1031 | static int process_register_request(struct sk_buff *skb, |
| 1032 | const char **dptr, unsigned int *datalen, |
| 1033 | unsigned int cseq) |
| 1034 | { |
| 1035 | enum ip_conntrack_info ctinfo; |
| 1036 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1037 | struct nf_conn_help *help = nfct_help(ct); |
| 1038 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1039 | unsigned int matchoff, matchlen; |
| 1040 | struct nf_conntrack_expect *exp; |
| 1041 | union nf_inet_addr *saddr, daddr; |
| 1042 | __be16 port; |
| 1043 | unsigned int expires = 0; |
| 1044 | int ret; |
| 1045 | typeof(nf_nat_sip_expect_hook) nf_nat_sip_expect; |
| 1046 | |
| 1047 | /* Expected connections can not register again. */ |
| 1048 | if (ct->status & IPS_EXPECTED) |
| 1049 | return NF_ACCEPT; |
| 1050 | |
| 1051 | /* We must check the expiration time: a value of zero signals the |
| 1052 | * registrar to release the binding. We'll remove our expectation |
| 1053 | * when receiving the new bindings in the response, but we don't |
| 1054 | * want to create new ones. |
| 1055 | * |
| 1056 | * The expiration time may be contained in Expires: header, the |
| 1057 | * Contact: header parameters or the URI parameters. |
| 1058 | */ |
| 1059 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, |
| 1060 | &matchoff, &matchlen) > 0) |
| 1061 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1062 | |
| 1063 | ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, |
| 1064 | SIP_HDR_CONTACT, NULL, |
| 1065 | &matchoff, &matchlen, &daddr, &port); |
| 1066 | if (ret < 0) |
| 1067 | return NF_DROP; |
| 1068 | else if (ret == 0) |
| 1069 | return NF_ACCEPT; |
| 1070 | |
| 1071 | /* We don't support third-party registrations */ |
| 1072 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr)) |
| 1073 | return NF_ACCEPT; |
| 1074 | |
| 1075 | if (ct_sip_parse_numerical_param(ct, *dptr, |
| 1076 | matchoff + matchlen, *datalen, |
| 1077 | "expires=", NULL, NULL, &expires) < 0) |
| 1078 | return NF_DROP; |
| 1079 | |
| 1080 | if (expires == 0) { |
| 1081 | ret = NF_ACCEPT; |
| 1082 | goto store_cseq; |
| 1083 | } |
| 1084 | |
| 1085 | exp = nf_ct_expect_alloc(ct); |
| 1086 | if (!exp) |
| 1087 | return NF_DROP; |
| 1088 | |
| 1089 | saddr = NULL; |
| 1090 | if (sip_direct_signalling) |
| 1091 | saddr = &ct->tuplehash[!dir].tuple.src.u3; |
| 1092 | |
Patrick McHardy | 5e8fbe2 | 2008-04-14 11:15:52 +0200 | [diff] [blame] | 1093 | nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct), |
| 1094 | saddr, &daddr, IPPROTO_UDP, NULL, &port); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1095 | exp->timeout.expires = sip_timeout * HZ; |
| 1096 | exp->helper = nfct_help(ct)->helper; |
| 1097 | exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE; |
| 1098 | |
| 1099 | nf_nat_sip_expect = rcu_dereference(nf_nat_sip_expect_hook); |
| 1100 | if (nf_nat_sip_expect && ct->status & IPS_NAT_MASK) |
| 1101 | ret = nf_nat_sip_expect(skb, dptr, datalen, exp, |
| 1102 | matchoff, matchlen); |
| 1103 | else { |
| 1104 | if (nf_ct_expect_related(exp) != 0) |
| 1105 | ret = NF_DROP; |
| 1106 | else |
| 1107 | ret = NF_ACCEPT; |
| 1108 | } |
| 1109 | nf_ct_expect_put(exp); |
| 1110 | |
| 1111 | store_cseq: |
| 1112 | if (ret == NF_ACCEPT) |
| 1113 | help->help.ct_sip_info.register_cseq = cseq; |
| 1114 | return ret; |
| 1115 | } |
| 1116 | |
| 1117 | static int process_register_response(struct sk_buff *skb, |
| 1118 | const char **dptr, unsigned int *datalen, |
| 1119 | unsigned int cseq, unsigned int code) |
| 1120 | { |
| 1121 | enum ip_conntrack_info ctinfo; |
| 1122 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1123 | struct nf_conn_help *help = nfct_help(ct); |
| 1124 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 1125 | union nf_inet_addr addr; |
| 1126 | __be16 port; |
| 1127 | unsigned int matchoff, matchlen, dataoff = 0; |
| 1128 | unsigned int expires = 0; |
| 1129 | int in_contact = 0, ret; |
| 1130 | |
| 1131 | /* According to RFC 3261, "UAs MUST NOT send a new registration until |
| 1132 | * they have received a final response from the registrar for the |
| 1133 | * previous one or the previous REGISTER request has timed out". |
| 1134 | * |
| 1135 | * However, some servers fail to detect retransmissions and send late |
| 1136 | * responses, so we store the sequence number of the last valid |
| 1137 | * request and compare it here. |
| 1138 | */ |
| 1139 | if (help->help.ct_sip_info.register_cseq != cseq) |
| 1140 | return NF_ACCEPT; |
| 1141 | |
| 1142 | if (code >= 100 && code <= 199) |
| 1143 | return NF_ACCEPT; |
| 1144 | if (code < 200 || code > 299) |
| 1145 | goto flush; |
| 1146 | |
| 1147 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_EXPIRES, |
| 1148 | &matchoff, &matchlen) > 0) |
| 1149 | expires = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1150 | |
| 1151 | while (1) { |
| 1152 | unsigned int c_expires = expires; |
| 1153 | |
| 1154 | ret = ct_sip_parse_header_uri(ct, *dptr, &dataoff, *datalen, |
| 1155 | SIP_HDR_CONTACT, &in_contact, |
| 1156 | &matchoff, &matchlen, |
| 1157 | &addr, &port); |
| 1158 | if (ret < 0) |
| 1159 | return NF_DROP; |
| 1160 | else if (ret == 0) |
| 1161 | break; |
| 1162 | |
| 1163 | /* We don't support third-party registrations */ |
| 1164 | if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr)) |
| 1165 | continue; |
| 1166 | |
| 1167 | ret = ct_sip_parse_numerical_param(ct, *dptr, |
| 1168 | matchoff + matchlen, |
| 1169 | *datalen, "expires=", |
| 1170 | NULL, NULL, &c_expires); |
| 1171 | if (ret < 0) |
| 1172 | return NF_DROP; |
| 1173 | if (c_expires == 0) |
| 1174 | break; |
| 1175 | if (refresh_signalling_expectation(ct, &addr, port, c_expires)) |
| 1176 | return NF_ACCEPT; |
| 1177 | } |
| 1178 | |
| 1179 | flush: |
| 1180 | flush_expectations(ct, false); |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1181 | return NF_ACCEPT; |
| 1182 | } |
| 1183 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1184 | static const struct sip_handler sip_handlers[] = { |
| 1185 | SIP_HANDLER("INVITE", process_sdp, process_invite_response), |
| 1186 | SIP_HANDLER("UPDATE", process_sdp, process_update_response), |
Patrick McHardy | 595a8ec | 2008-03-25 20:22:53 -0700 | [diff] [blame] | 1187 | SIP_HANDLER("ACK", process_sdp, NULL), |
| 1188 | SIP_HANDLER("PRACK", process_sdp, process_prack_response), |
Patrick McHardy | 9467ee3 | 2008-03-25 20:24:04 -0700 | [diff] [blame] | 1189 | SIP_HANDLER("BYE", process_bye_request, NULL), |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1190 | SIP_HANDLER("REGISTER", process_register_request, process_register_response), |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1191 | }; |
| 1192 | |
| 1193 | static int process_sip_response(struct sk_buff *skb, |
| 1194 | const char **dptr, unsigned int *datalen) |
| 1195 | { |
| 1196 | static const struct sip_handler *handler; |
| 1197 | enum ip_conntrack_info ctinfo; |
| 1198 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1199 | unsigned int matchoff, matchlen; |
| 1200 | unsigned int code, cseq, dataoff, i; |
| 1201 | |
| 1202 | if (*datalen < strlen("SIP/2.0 200")) |
| 1203 | return NF_ACCEPT; |
| 1204 | code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10); |
| 1205 | if (!code) |
| 1206 | return NF_DROP; |
| 1207 | |
| 1208 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, |
| 1209 | &matchoff, &matchlen) <= 0) |
| 1210 | return NF_DROP; |
| 1211 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1212 | if (!cseq) |
| 1213 | return NF_DROP; |
| 1214 | dataoff = matchoff + matchlen + 1; |
| 1215 | |
| 1216 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { |
| 1217 | handler = &sip_handlers[i]; |
| 1218 | if (handler->response == NULL) |
| 1219 | continue; |
| 1220 | if (*datalen < dataoff + handler->len || |
| 1221 | strnicmp(*dptr + dataoff, handler->method, handler->len)) |
| 1222 | continue; |
| 1223 | return handler->response(skb, dptr, datalen, cseq, code); |
| 1224 | } |
| 1225 | return NF_ACCEPT; |
| 1226 | } |
| 1227 | |
| 1228 | static int process_sip_request(struct sk_buff *skb, |
| 1229 | const char **dptr, unsigned int *datalen) |
| 1230 | { |
| 1231 | static const struct sip_handler *handler; |
| 1232 | enum ip_conntrack_info ctinfo; |
| 1233 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 1234 | unsigned int matchoff, matchlen; |
| 1235 | unsigned int cseq, i; |
| 1236 | |
| 1237 | for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) { |
| 1238 | handler = &sip_handlers[i]; |
| 1239 | if (handler->request == NULL) |
| 1240 | continue; |
| 1241 | if (*datalen < handler->len || |
| 1242 | strnicmp(*dptr, handler->method, handler->len)) |
| 1243 | continue; |
| 1244 | |
| 1245 | if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ, |
| 1246 | &matchoff, &matchlen) <= 0) |
| 1247 | return NF_DROP; |
| 1248 | cseq = simple_strtoul(*dptr + matchoff, NULL, 10); |
| 1249 | if (!cseq) |
| 1250 | return NF_DROP; |
| 1251 | |
| 1252 | return handler->request(skb, dptr, datalen, cseq); |
| 1253 | } |
| 1254 | return NF_ACCEPT; |
| 1255 | } |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1256 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1257 | static int sip_help(struct sk_buff *skb, |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1258 | unsigned int protoff, |
| 1259 | struct nf_conn *ct, |
| 1260 | enum ip_conntrack_info ctinfo) |
| 1261 | { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1262 | unsigned int dataoff, datalen; |
| 1263 | const char *dptr; |
Patrick McHardy | 33cb1e9 | 2008-03-25 20:22:37 -0700 | [diff] [blame] | 1264 | int ret; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1265 | typeof(nf_nat_sip_hook) nf_nat_sip; |
| 1266 | |
| 1267 | /* No Data ? */ |
| 1268 | dataoff = protoff + sizeof(struct udphdr); |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1269 | if (dataoff >= skb->len) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1270 | return NF_ACCEPT; |
| 1271 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1272 | nf_ct_refresh(ct, skb, sip_timeout * HZ); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1273 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1274 | if (!skb_is_nonlinear(skb)) |
| 1275 | dptr = skb->data + dataoff; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1276 | else { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 1277 | pr_debug("Copy of skbuff not supported yet.\n"); |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1278 | return NF_ACCEPT; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1279 | } |
| 1280 | |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 1281 | datalen = skb->len - dataoff; |
Patrick McHardy | 779382e | 2008-03-25 20:17:36 -0700 | [diff] [blame] | 1282 | if (datalen < strlen("SIP/2.0 200")) |
Patrick McHardy | 7d3dd04 | 2008-03-25 20:19:46 -0700 | [diff] [blame] | 1283 | return NF_ACCEPT; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1284 | |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1285 | if (strnicmp(dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0) |
Patrick McHardy | 33cb1e9 | 2008-03-25 20:22:37 -0700 | [diff] [blame] | 1286 | ret = process_sip_request(skb, &dptr, &datalen); |
Patrick McHardy | 30f33e6 | 2008-03-25 20:22:20 -0700 | [diff] [blame] | 1287 | else |
Patrick McHardy | 33cb1e9 | 2008-03-25 20:22:37 -0700 | [diff] [blame] | 1288 | ret = process_sip_response(skb, &dptr, &datalen); |
| 1289 | |
| 1290 | if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) { |
| 1291 | nf_nat_sip = rcu_dereference(nf_nat_sip_hook); |
| 1292 | if (nf_nat_sip && !nf_nat_sip(skb, &dptr, &datalen)) |
| 1293 | ret = NF_DROP; |
| 1294 | } |
| 1295 | |
| 1296 | return ret; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1297 | } |
| 1298 | |
| 1299 | static struct nf_conntrack_helper sip[MAX_PORTS][2] __read_mostly; |
| 1300 | static char sip_names[MAX_PORTS][2][sizeof("sip-65535")] __read_mostly; |
| 1301 | |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1302 | static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { |
| 1303 | [SIP_EXPECT_SIGNALLING] = { |
| 1304 | .max_expected = 1, |
| 1305 | .timeout = 3 * 60, |
| 1306 | }, |
| 1307 | [SIP_EXPECT_AUDIO] = { |
Patrick McHardy | a9c1d35 | 2008-03-25 20:25:49 -0700 | [diff] [blame] | 1308 | .max_expected = 2 * IP_CT_DIR_MAX, |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1309 | .timeout = 3 * 60, |
| 1310 | }, |
Patrick McHardy | 0d0ab03 | 2008-03-25 20:26:24 -0700 | [diff] [blame] | 1311 | [SIP_EXPECT_VIDEO] = { |
| 1312 | .max_expected = 2 * IP_CT_DIR_MAX, |
| 1313 | .timeout = 3 * 60, |
| 1314 | }, |
Patrick McHardy | 6002f266 | 2008-03-25 20:09:15 -0700 | [diff] [blame] | 1315 | }; |
| 1316 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1317 | static void nf_conntrack_sip_fini(void) |
| 1318 | { |
| 1319 | int i, j; |
| 1320 | |
| 1321 | for (i = 0; i < ports_c; i++) { |
| 1322 | for (j = 0; j < 2; j++) { |
| 1323 | if (sip[i][j].me == NULL) |
| 1324 | continue; |
| 1325 | nf_conntrack_helper_unregister(&sip[i][j]); |
| 1326 | } |
| 1327 | } |
| 1328 | } |
| 1329 | |
| 1330 | static int __init nf_conntrack_sip_init(void) |
| 1331 | { |
| 1332 | int i, j, ret; |
| 1333 | char *tmpname; |
| 1334 | |
| 1335 | if (ports_c == 0) |
| 1336 | ports[ports_c++] = SIP_PORT; |
| 1337 | |
| 1338 | for (i = 0; i < ports_c; i++) { |
| 1339 | memset(&sip[i], 0, sizeof(sip[i])); |
| 1340 | |
| 1341 | sip[i][0].tuple.src.l3num = AF_INET; |
| 1342 | sip[i][1].tuple.src.l3num = AF_INET6; |
| 1343 | for (j = 0; j < 2; j++) { |
| 1344 | sip[i][j].tuple.dst.protonum = IPPROTO_UDP; |
| 1345 | sip[i][j].tuple.src.u.udp.port = htons(ports[i]); |
Patrick McHardy | 0f32a40 | 2008-03-25 20:25:13 -0700 | [diff] [blame] | 1346 | sip[i][j].expect_policy = sip_exp_policy; |
| 1347 | sip[i][j].expect_class_max = SIP_EXPECT_MAX; |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1348 | sip[i][j].me = THIS_MODULE; |
| 1349 | sip[i][j].help = sip_help; |
| 1350 | |
| 1351 | tmpname = &sip_names[i][j][0]; |
| 1352 | if (ports[i] == SIP_PORT) |
| 1353 | sprintf(tmpname, "sip"); |
| 1354 | else |
| 1355 | sprintf(tmpname, "sip-%u", i); |
| 1356 | sip[i][j].name = tmpname; |
| 1357 | |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 1358 | pr_debug("port #%u: %u\n", i, ports[i]); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 1359 | |
| 1360 | ret = nf_conntrack_helper_register(&sip[i][j]); |
| 1361 | if (ret) { |
| 1362 | printk("nf_ct_sip: failed to register helper " |
| 1363 | "for pf: %u port: %u\n", |
| 1364 | sip[i][j].tuple.src.l3num, ports[i]); |
| 1365 | nf_conntrack_sip_fini(); |
| 1366 | return ret; |
| 1367 | } |
| 1368 | } |
| 1369 | } |
| 1370 | return 0; |
| 1371 | } |
| 1372 | |
| 1373 | module_init(nf_conntrack_sip_init); |
| 1374 | module_exit(nf_conntrack_sip_fini); |