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. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/ctype.h> |
| 13 | #include <linux/skbuff.h> |
| 14 | #include <linux/inet.h> |
| 15 | #include <linux/in.h> |
| 16 | #include <linux/udp.h> |
Yasuyuki Kozakai | 1863f09 | 2006-12-02 22:12:54 -0800 | [diff] [blame] | 17 | #include <linux/netfilter.h> |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 18 | |
| 19 | #include <net/netfilter/nf_conntrack.h> |
| 20 | #include <net/netfilter/nf_conntrack_expect.h> |
| 21 | #include <net/netfilter/nf_conntrack_helper.h> |
| 22 | #include <linux/netfilter/nf_conntrack_sip.h> |
| 23 | |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 24 | MODULE_LICENSE("GPL"); |
| 25 | MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>"); |
| 26 | MODULE_DESCRIPTION("SIP connection tracking helper"); |
| 27 | MODULE_ALIAS("ip_conntrack_sip"); |
| 28 | |
| 29 | #define MAX_PORTS 8 |
| 30 | static unsigned short ports[MAX_PORTS]; |
| 31 | static int ports_c; |
| 32 | module_param_array(ports, ushort, &ports_c, 0400); |
| 33 | MODULE_PARM_DESC(ports, "port numbers of SIP servers"); |
| 34 | |
| 35 | static unsigned int sip_timeout __read_mostly = SIP_TIMEOUT; |
| 36 | module_param(sip_timeout, uint, 0600); |
| 37 | MODULE_PARM_DESC(sip_timeout, "timeout for the master SIP session"); |
| 38 | |
| 39 | unsigned int (*nf_nat_sip_hook)(struct sk_buff **pskb, |
| 40 | enum ip_conntrack_info ctinfo, |
| 41 | struct nf_conn *ct, |
| 42 | const char **dptr) __read_mostly; |
| 43 | EXPORT_SYMBOL_GPL(nf_nat_sip_hook); |
| 44 | |
| 45 | unsigned int (*nf_nat_sdp_hook)(struct sk_buff **pskb, |
| 46 | enum ip_conntrack_info ctinfo, |
| 47 | struct nf_conntrack_expect *exp, |
| 48 | const char *dptr) __read_mostly; |
| 49 | EXPORT_SYMBOL_GPL(nf_nat_sdp_hook); |
| 50 | |
| 51 | static int digits_len(struct nf_conn *, const char *, const char *, int *); |
| 52 | static int epaddr_len(struct nf_conn *, const char *, const char *, int *); |
| 53 | static int skp_digits_len(struct nf_conn *, const char *, const char *, int *); |
| 54 | static int skp_epaddr_len(struct nf_conn *, const char *, const char *, int *); |
| 55 | |
| 56 | struct sip_header_nfo { |
| 57 | const char *lname; |
| 58 | const char *sname; |
| 59 | const char *ln_str; |
| 60 | size_t lnlen; |
| 61 | size_t snlen; |
| 62 | size_t ln_strlen; |
| 63 | int case_sensitive; |
| 64 | int (*match_len)(struct nf_conn *, const char *, |
| 65 | const char *, int *); |
| 66 | }; |
| 67 | |
| 68 | static const struct sip_header_nfo ct_sip_hdrs[] = { |
| 69 | [POS_REG_REQ_URI] = { /* SIP REGISTER request URI */ |
| 70 | .lname = "sip:", |
| 71 | .lnlen = sizeof("sip:") - 1, |
| 72 | .ln_str = ":", |
| 73 | .ln_strlen = sizeof(":") - 1, |
| 74 | .match_len = epaddr_len, |
| 75 | }, |
| 76 | [POS_REQ_URI] = { /* SIP request URI */ |
| 77 | .lname = "sip:", |
| 78 | .lnlen = sizeof("sip:") - 1, |
| 79 | .ln_str = "@", |
| 80 | .ln_strlen = sizeof("@") - 1, |
| 81 | .match_len = epaddr_len, |
| 82 | }, |
| 83 | [POS_FROM] = { /* SIP From header */ |
| 84 | .lname = "From:", |
| 85 | .lnlen = sizeof("From:") - 1, |
| 86 | .sname = "\r\nf:", |
| 87 | .snlen = sizeof("\r\nf:") - 1, |
| 88 | .ln_str = "sip:", |
| 89 | .ln_strlen = sizeof("sip:") - 1, |
| 90 | .match_len = skp_epaddr_len, |
| 91 | }, |
| 92 | [POS_TO] = { /* SIP To header */ |
| 93 | .lname = "To:", |
| 94 | .lnlen = sizeof("To:") - 1, |
| 95 | .sname = "\r\nt:", |
| 96 | .snlen = sizeof("\r\nt:") - 1, |
| 97 | .ln_str = "sip:", |
| 98 | .ln_strlen = sizeof("sip:") - 1, |
| 99 | .match_len = skp_epaddr_len |
| 100 | }, |
| 101 | [POS_VIA] = { /* SIP Via header */ |
| 102 | .lname = "Via:", |
| 103 | .lnlen = sizeof("Via:") - 1, |
| 104 | .sname = "\r\nv:", |
| 105 | .snlen = sizeof("\r\nv:") - 1, /* rfc3261 "\r\n" */ |
| 106 | .ln_str = "UDP ", |
| 107 | .ln_strlen = sizeof("UDP ") - 1, |
| 108 | .match_len = epaddr_len, |
| 109 | }, |
| 110 | [POS_CONTACT] = { /* SIP Contact header */ |
| 111 | .lname = "Contact:", |
| 112 | .lnlen = sizeof("Contact:") - 1, |
| 113 | .sname = "\r\nm:", |
| 114 | .snlen = sizeof("\r\nm:") - 1, |
| 115 | .ln_str = "sip:", |
| 116 | .ln_strlen = sizeof("sip:") - 1, |
| 117 | .match_len = skp_epaddr_len |
| 118 | }, |
| 119 | [POS_CONTENT] = { /* SIP Content length header */ |
| 120 | .lname = "Content-Length:", |
| 121 | .lnlen = sizeof("Content-Length:") - 1, |
| 122 | .sname = "\r\nl:", |
| 123 | .snlen = sizeof("\r\nl:") - 1, |
| 124 | .ln_str = ":", |
| 125 | .ln_strlen = sizeof(":") - 1, |
| 126 | .match_len = skp_digits_len |
| 127 | }, |
| 128 | [POS_MEDIA] = { /* SDP media info */ |
| 129 | .case_sensitive = 1, |
| 130 | .lname = "\nm=", |
| 131 | .lnlen = sizeof("\nm=") - 1, |
| 132 | .sname = "\rm=", |
| 133 | .snlen = sizeof("\rm=") - 1, |
| 134 | .ln_str = "audio ", |
| 135 | .ln_strlen = sizeof("audio ") - 1, |
| 136 | .match_len = digits_len |
| 137 | }, |
| 138 | [POS_OWNER_IP4] = { /* SDP owner address*/ |
| 139 | .case_sensitive = 1, |
| 140 | .lname = "\no=", |
| 141 | .lnlen = sizeof("\no=") - 1, |
| 142 | .sname = "\ro=", |
| 143 | .snlen = sizeof("\ro=") - 1, |
| 144 | .ln_str = "IN IP4 ", |
| 145 | .ln_strlen = sizeof("IN IP4 ") - 1, |
| 146 | .match_len = epaddr_len |
| 147 | }, |
| 148 | [POS_CONNECTION_IP4] = {/* SDP connection info */ |
| 149 | .case_sensitive = 1, |
| 150 | .lname = "\nc=", |
| 151 | .lnlen = sizeof("\nc=") - 1, |
| 152 | .sname = "\rc=", |
| 153 | .snlen = sizeof("\rc=") - 1, |
| 154 | .ln_str = "IN IP4 ", |
| 155 | .ln_strlen = sizeof("IN IP4 ") - 1, |
| 156 | .match_len = epaddr_len |
| 157 | }, |
| 158 | [POS_OWNER_IP6] = { /* SDP owner address*/ |
| 159 | .case_sensitive = 1, |
| 160 | .lname = "\no=", |
| 161 | .lnlen = sizeof("\no=") - 1, |
| 162 | .sname = "\ro=", |
| 163 | .snlen = sizeof("\ro=") - 1, |
| 164 | .ln_str = "IN IP6 ", |
| 165 | .ln_strlen = sizeof("IN IP6 ") - 1, |
| 166 | .match_len = epaddr_len |
| 167 | }, |
| 168 | [POS_CONNECTION_IP6] = {/* SDP connection info */ |
| 169 | .case_sensitive = 1, |
| 170 | .lname = "\nc=", |
| 171 | .lnlen = sizeof("\nc=") - 1, |
| 172 | .sname = "\rc=", |
| 173 | .snlen = sizeof("\rc=") - 1, |
| 174 | .ln_str = "IN IP6 ", |
| 175 | .ln_strlen = sizeof("IN IP6 ") - 1, |
| 176 | .match_len = epaddr_len |
| 177 | }, |
| 178 | [POS_SDP_HEADER] = { /* SDP version header */ |
| 179 | .case_sensitive = 1, |
| 180 | .lname = "\nv=", |
| 181 | .lnlen = sizeof("\nv=") - 1, |
| 182 | .sname = "\rv=", |
| 183 | .snlen = sizeof("\rv=") - 1, |
| 184 | .ln_str = "=", |
| 185 | .ln_strlen = sizeof("=") - 1, |
| 186 | .match_len = digits_len |
| 187 | } |
| 188 | }; |
| 189 | |
| 190 | /* get line lenght until first CR or LF seen. */ |
| 191 | int ct_sip_lnlen(const char *line, const char *limit) |
| 192 | { |
| 193 | const char *k = line; |
| 194 | |
| 195 | while ((line <= limit) && (*line == '\r' || *line == '\n')) |
| 196 | line++; |
| 197 | |
| 198 | while (line <= limit) { |
| 199 | if (*line == '\r' || *line == '\n') |
| 200 | break; |
| 201 | line++; |
| 202 | } |
| 203 | return line - k; |
| 204 | } |
| 205 | EXPORT_SYMBOL_GPL(ct_sip_lnlen); |
| 206 | |
| 207 | /* Linear string search, case sensitive. */ |
| 208 | const char *ct_sip_search(const char *needle, const char *haystack, |
| 209 | size_t needle_len, size_t haystack_len, |
| 210 | int case_sensitive) |
| 211 | { |
| 212 | const char *limit = haystack + (haystack_len - needle_len); |
| 213 | |
| 214 | while (haystack <= limit) { |
| 215 | if (case_sensitive) { |
| 216 | if (strncmp(haystack, needle, needle_len) == 0) |
| 217 | return haystack; |
| 218 | } else { |
| 219 | if (strnicmp(haystack, needle, needle_len) == 0) |
| 220 | return haystack; |
| 221 | } |
| 222 | haystack++; |
| 223 | } |
| 224 | return NULL; |
| 225 | } |
| 226 | EXPORT_SYMBOL_GPL(ct_sip_search); |
| 227 | |
| 228 | static int digits_len(struct nf_conn *ct, const char *dptr, |
| 229 | const char *limit, int *shift) |
| 230 | { |
| 231 | int len = 0; |
| 232 | while (dptr <= limit && isdigit(*dptr)) { |
| 233 | dptr++; |
| 234 | len++; |
| 235 | } |
| 236 | return len; |
| 237 | } |
| 238 | |
| 239 | /* get digits lenght, skiping blank spaces. */ |
| 240 | static int skp_digits_len(struct nf_conn *ct, const char *dptr, |
| 241 | const char *limit, int *shift) |
| 242 | { |
| 243 | for (; dptr <= limit && *dptr == ' '; dptr++) |
| 244 | (*shift)++; |
| 245 | |
| 246 | return digits_len(ct, dptr, limit, shift); |
| 247 | } |
| 248 | |
| 249 | static int parse_addr(struct nf_conn *ct, const char *cp, const char **endp, |
| 250 | union nf_conntrack_address *addr, const char *limit) |
| 251 | { |
| 252 | const char *end; |
| 253 | int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; |
| 254 | int ret = 0; |
| 255 | |
| 256 | switch (family) { |
| 257 | case AF_INET: |
| 258 | ret = in4_pton(cp, limit - cp, (u8 *)&addr->ip, -1, &end); |
| 259 | break; |
| 260 | case AF_INET6: |
| 261 | ret = in6_pton(cp, limit - cp, (u8 *)&addr->ip6, -1, &end); |
| 262 | break; |
| 263 | default: |
| 264 | BUG(); |
| 265 | } |
| 266 | |
| 267 | if (ret == 0 || end == cp) |
| 268 | return 0; |
| 269 | if (endp) |
| 270 | *endp = end; |
| 271 | return 1; |
| 272 | } |
| 273 | |
| 274 | /* skip ip address. returns its length. */ |
| 275 | static int epaddr_len(struct nf_conn *ct, const char *dptr, |
| 276 | const char *limit, int *shift) |
| 277 | { |
| 278 | union nf_conntrack_address addr; |
| 279 | const char *aux = dptr; |
| 280 | |
| 281 | if (!parse_addr(ct, dptr, &dptr, &addr, limit)) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 282 | pr_debug("ip: %s parse failed.!\n", dptr); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 283 | return 0; |
| 284 | } |
| 285 | |
| 286 | /* Port number */ |
| 287 | if (*dptr == ':') { |
| 288 | dptr++; |
| 289 | dptr += digits_len(ct, dptr, limit, shift); |
| 290 | } |
| 291 | return dptr - aux; |
| 292 | } |
| 293 | |
| 294 | /* get address length, skiping user info. */ |
| 295 | static int skp_epaddr_len(struct nf_conn *ct, const char *dptr, |
| 296 | const char *limit, int *shift) |
| 297 | { |
| 298 | int s = *shift; |
| 299 | |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 300 | /* Search for @, but stop at the end of the line. |
| 301 | * We are inside a sip: URI, so we don't need to worry about |
| 302 | * continuation lines. */ |
| 303 | while (dptr <= limit && |
| 304 | *dptr != '@' && *dptr != '\r' && *dptr != '\n') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 305 | (*shift)++; |
Lars Immisch | 7da5bfb | 2007-01-30 14:24:57 -0800 | [diff] [blame] | 306 | dptr++; |
| 307 | } |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 308 | |
Patrick McHardy | adcb471 | 2007-01-30 14:25:24 -0800 | [diff] [blame] | 309 | if (dptr <= limit && *dptr == '@') { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 310 | dptr++; |
| 311 | (*shift)++; |
| 312 | } else |
| 313 | *shift = s; |
| 314 | |
| 315 | return epaddr_len(ct, dptr, limit, shift); |
| 316 | } |
| 317 | |
| 318 | /* Returns 0 if not found, -1 error parsing. */ |
| 319 | int ct_sip_get_info(struct nf_conn *ct, |
| 320 | const char *dptr, size_t dlen, |
| 321 | unsigned int *matchoff, |
| 322 | unsigned int *matchlen, |
| 323 | enum sip_header_pos pos) |
| 324 | { |
| 325 | const struct sip_header_nfo *hnfo = &ct_sip_hdrs[pos]; |
| 326 | const char *limit, *aux, *k = dptr; |
| 327 | int shift = 0; |
| 328 | |
| 329 | limit = dptr + (dlen - hnfo->lnlen); |
| 330 | |
| 331 | while (dptr <= limit) { |
| 332 | if ((strncmp(dptr, hnfo->lname, hnfo->lnlen) != 0) && |
Patrick McHardy | 465f90a | 2007-08-14 13:13:54 -0700 | [diff] [blame^] | 333 | (hnfo->sname == NULL || |
| 334 | strncmp(dptr, hnfo->sname, hnfo->snlen) != 0)) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 335 | dptr++; |
| 336 | continue; |
| 337 | } |
| 338 | aux = ct_sip_search(hnfo->ln_str, dptr, hnfo->ln_strlen, |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 339 | ct_sip_lnlen(dptr, limit), |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 340 | hnfo->case_sensitive); |
| 341 | if (!aux) { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 342 | pr_debug("'%s' not found in '%s'.\n", hnfo->ln_str, |
| 343 | hnfo->lname); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 344 | return -1; |
| 345 | } |
| 346 | aux += hnfo->ln_strlen; |
| 347 | |
| 348 | *matchlen = hnfo->match_len(ct, aux, limit, &shift); |
| 349 | if (!*matchlen) |
| 350 | return -1; |
| 351 | |
| 352 | *matchoff = (aux - k) + shift; |
| 353 | |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 354 | pr_debug("%s match succeeded! - len: %u\n", hnfo->lname, |
| 355 | *matchlen); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 356 | return 1; |
| 357 | } |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 358 | pr_debug("%s header not found.\n", hnfo->lname); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 359 | return 0; |
| 360 | } |
| 361 | EXPORT_SYMBOL_GPL(ct_sip_get_info); |
| 362 | |
| 363 | static int set_expected_rtp(struct sk_buff **pskb, |
| 364 | struct nf_conn *ct, |
| 365 | enum ip_conntrack_info ctinfo, |
| 366 | union nf_conntrack_address *addr, |
| 367 | __be16 port, |
| 368 | const char *dptr) |
| 369 | { |
| 370 | struct nf_conntrack_expect *exp; |
| 371 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| 372 | int family = ct->tuplehash[!dir].tuple.src.l3num; |
| 373 | int ret; |
| 374 | typeof(nf_nat_sdp_hook) nf_nat_sdp; |
| 375 | |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 376 | exp = nf_ct_expect_alloc(ct); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 377 | if (exp == NULL) |
| 378 | return NF_DROP; |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 379 | nf_ct_expect_init(exp, family, |
| 380 | &ct->tuplehash[!dir].tuple.src.u3, addr, |
| 381 | IPPROTO_UDP, NULL, &port); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 382 | |
| 383 | nf_nat_sdp = rcu_dereference(nf_nat_sdp_hook); |
| 384 | if (nf_nat_sdp && ct->status & IPS_NAT_MASK) |
| 385 | ret = nf_nat_sdp(pskb, ctinfo, exp, dptr); |
| 386 | else { |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 387 | if (nf_ct_expect_related(exp) != 0) |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 388 | ret = NF_DROP; |
| 389 | else |
| 390 | ret = NF_ACCEPT; |
| 391 | } |
Patrick McHardy | 6823645 | 2007-07-07 22:30:49 -0700 | [diff] [blame] | 392 | nf_ct_expect_put(exp); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 393 | |
| 394 | return ret; |
| 395 | } |
| 396 | |
| 397 | static int sip_help(struct sk_buff **pskb, |
| 398 | unsigned int protoff, |
| 399 | struct nf_conn *ct, |
| 400 | enum ip_conntrack_info ctinfo) |
| 401 | { |
| 402 | int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; |
| 403 | union nf_conntrack_address addr; |
| 404 | unsigned int dataoff, datalen; |
| 405 | const char *dptr; |
| 406 | int ret = NF_ACCEPT; |
| 407 | int matchoff, matchlen; |
| 408 | u_int16_t port; |
| 409 | enum sip_header_pos pos; |
| 410 | typeof(nf_nat_sip_hook) nf_nat_sip; |
| 411 | |
| 412 | /* No Data ? */ |
| 413 | dataoff = protoff + sizeof(struct udphdr); |
| 414 | if (dataoff >= (*pskb)->len) |
| 415 | return NF_ACCEPT; |
| 416 | |
| 417 | nf_ct_refresh(ct, *pskb, sip_timeout * HZ); |
| 418 | |
| 419 | if (!skb_is_nonlinear(*pskb)) |
| 420 | dptr = (*pskb)->data + dataoff; |
| 421 | else { |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 422 | pr_debug("Copy of skbuff not supported yet.\n"); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 423 | goto out; |
| 424 | } |
| 425 | |
| 426 | nf_nat_sip = rcu_dereference(nf_nat_sip_hook); |
| 427 | if (nf_nat_sip && ct->status & IPS_NAT_MASK) { |
| 428 | if (!nf_nat_sip(pskb, ctinfo, ct, &dptr)) { |
| 429 | ret = NF_DROP; |
| 430 | goto out; |
| 431 | } |
| 432 | } |
| 433 | |
| 434 | datalen = (*pskb)->len - dataoff; |
| 435 | if (datalen < sizeof("SIP/2.0 200") - 1) |
| 436 | goto out; |
| 437 | |
| 438 | /* RTP info only in some SDP pkts */ |
| 439 | if (memcmp(dptr, "INVITE", sizeof("INVITE") - 1) != 0 && |
Jerome Borsboom | d258131 | 2007-06-22 14:08:17 -0700 | [diff] [blame] | 440 | memcmp(dptr, "UPDATE", sizeof("UPDATE") - 1) != 0 && |
| 441 | memcmp(dptr, "SIP/2.0 180", sizeof("SIP/2.0 180") - 1) != 0 && |
| 442 | memcmp(dptr, "SIP/2.0 183", sizeof("SIP/2.0 183") - 1) != 0 && |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 443 | memcmp(dptr, "SIP/2.0 200", sizeof("SIP/2.0 200") - 1) != 0) { |
| 444 | goto out; |
| 445 | } |
| 446 | /* Get address and port from SDP packet. */ |
| 447 | pos = family == AF_INET ? POS_CONNECTION_IP4 : POS_CONNECTION_IP6; |
| 448 | if (ct_sip_get_info(ct, dptr, datalen, &matchoff, &matchlen, pos) > 0) { |
| 449 | |
| 450 | /* We'll drop only if there are parse problems. */ |
| 451 | if (!parse_addr(ct, dptr + matchoff, NULL, &addr, |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 452 | dptr + datalen)) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 453 | ret = NF_DROP; |
| 454 | goto out; |
| 455 | } |
| 456 | if (ct_sip_get_info(ct, dptr, datalen, &matchoff, &matchlen, |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 457 | POS_MEDIA) > 0) { |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 458 | |
| 459 | port = simple_strtoul(dptr + matchoff, NULL, 10); |
| 460 | if (port < 1024) { |
| 461 | ret = NF_DROP; |
| 462 | goto out; |
| 463 | } |
| 464 | ret = set_expected_rtp(pskb, ct, ctinfo, &addr, |
| 465 | htons(port), dptr); |
| 466 | } |
| 467 | } |
| 468 | out: |
| 469 | return ret; |
| 470 | } |
| 471 | |
| 472 | static struct nf_conntrack_helper sip[MAX_PORTS][2] __read_mostly; |
| 473 | static char sip_names[MAX_PORTS][2][sizeof("sip-65535")] __read_mostly; |
| 474 | |
| 475 | static void nf_conntrack_sip_fini(void) |
| 476 | { |
| 477 | int i, j; |
| 478 | |
| 479 | for (i = 0; i < ports_c; i++) { |
| 480 | for (j = 0; j < 2; j++) { |
| 481 | if (sip[i][j].me == NULL) |
| 482 | continue; |
| 483 | nf_conntrack_helper_unregister(&sip[i][j]); |
| 484 | } |
| 485 | } |
| 486 | } |
| 487 | |
| 488 | static int __init nf_conntrack_sip_init(void) |
| 489 | { |
| 490 | int i, j, ret; |
| 491 | char *tmpname; |
| 492 | |
| 493 | if (ports_c == 0) |
| 494 | ports[ports_c++] = SIP_PORT; |
| 495 | |
| 496 | for (i = 0; i < ports_c; i++) { |
| 497 | memset(&sip[i], 0, sizeof(sip[i])); |
| 498 | |
| 499 | sip[i][0].tuple.src.l3num = AF_INET; |
| 500 | sip[i][1].tuple.src.l3num = AF_INET6; |
| 501 | for (j = 0; j < 2; j++) { |
| 502 | sip[i][j].tuple.dst.protonum = IPPROTO_UDP; |
| 503 | sip[i][j].tuple.src.u.udp.port = htons(ports[i]); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 504 | sip[i][j].max_expected = 2; |
| 505 | sip[i][j].timeout = 3 * 60; /* 3 minutes */ |
| 506 | sip[i][j].me = THIS_MODULE; |
| 507 | sip[i][j].help = sip_help; |
| 508 | |
| 509 | tmpname = &sip_names[i][j][0]; |
| 510 | if (ports[i] == SIP_PORT) |
| 511 | sprintf(tmpname, "sip"); |
| 512 | else |
| 513 | sprintf(tmpname, "sip-%u", i); |
| 514 | sip[i][j].name = tmpname; |
| 515 | |
Patrick McHardy | 0d53778 | 2007-07-07 22:39:38 -0700 | [diff] [blame] | 516 | pr_debug("port #%u: %u\n", i, ports[i]); |
Patrick McHardy | 9fafcd7 | 2006-12-02 22:09:57 -0800 | [diff] [blame] | 517 | |
| 518 | ret = nf_conntrack_helper_register(&sip[i][j]); |
| 519 | if (ret) { |
| 520 | printk("nf_ct_sip: failed to register helper " |
| 521 | "for pf: %u port: %u\n", |
| 522 | sip[i][j].tuple.src.l3num, ports[i]); |
| 523 | nf_conntrack_sip_fini(); |
| 524 | return ret; |
| 525 | } |
| 526 | } |
| 527 | } |
| 528 | return 0; |
| 529 | } |
| 530 | |
| 531 | module_init(nf_conntrack_sip_init); |
| 532 | module_exit(nf_conntrack_sip_fini); |