diff options
| -rw-r--r-- | include/linux/netfilter/nf_conntrack_sip.h | 5 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_sip.c | 107 |
2 files changed, 112 insertions, 0 deletions
diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h index ccc701422963..87bc6f79efc4 100644 --- a/include/linux/netfilter/nf_conntrack_sip.h +++ b/include/linux/netfilter/nf_conntrack_sip.h @@ -67,6 +67,11 @@ extern int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, unsigned int dataoff, unsigned int datalen, enum sip_header_types type, unsigned int *matchoff, unsigned int *matchlen); +extern int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, + unsigned int *dataoff, unsigned int datalen, + enum sip_header_types type, int *in_header, + unsigned int *matchoff, unsigned int *matchlen, + union nf_inet_addr *addr, __be16 *port); extern int ct_sip_get_sdp_header(const struct nf_conn *ct, const char *dptr, unsigned int dataoff, unsigned int datalen, diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index cbc91598acee..a74d76a97312 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -190,6 +190,9 @@ EXPORT_SYMBOL_GPL(ct_sip_parse_request); * whitespace and the values. Whitespace in this context means any amount of * tabs, spaces and continuation lines, which are treated as a single whitespace * character. + * + * Some headers may appear multiple times. A comma seperated list of values is + * equivalent to multiple headers. */ static const struct sip_header ct_sip_hdrs[] = { [SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len), @@ -322,6 +325,110 @@ int ct_sip_get_header(const struct nf_conn *ct, const char *dptr, } EXPORT_SYMBOL_GPL(ct_sip_get_header); +/* Get next header field in a list of comma seperated values */ +static int ct_sip_next_header(const struct nf_conn *ct, const char *dptr, + unsigned int dataoff, unsigned int datalen, + enum sip_header_types type, + unsigned int *matchoff, unsigned int *matchlen) +{ + const struct sip_header *hdr = &ct_sip_hdrs[type]; + const char *start = dptr, *limit = dptr + datalen; + int shift = 0; + + dptr += dataoff; + + dptr = ct_sip_header_search(dptr, limit, ",", strlen(",")); + if (!dptr) + return 0; + + dptr = ct_sip_header_search(dptr, limit, hdr->search, hdr->slen); + if (!dptr) + return 0; + dptr += hdr->slen; + + *matchoff = dptr - start; + *matchlen = hdr->match_len(ct, dptr, limit, &shift); + if (!*matchlen) + return -1; + *matchoff += shift; + return 1; +} + +/* Walk through headers until a parsable one is found or no header of the + * given type is left. */ +static int ct_sip_walk_headers(const struct nf_conn *ct, const char *dptr, + unsigned int dataoff, unsigned int datalen, + enum sip_header_types type, int *in_header, + unsigned int *matchoff, unsigned int *matchlen) +{ + int ret; + + if (in_header && *in_header) { + while (1) { + ret = ct_sip_next_header(ct, dptr, dataoff, datalen, + type, matchoff, matchlen); + if (ret > 0) + return ret; + if (ret == 0) + break; + dataoff += *matchoff; + } + *in_header = 0; + } + + while (1) { + ret = ct_sip_get_header(ct, dptr, dataoff, datalen, + type, matchoff, matchlen); + if (ret > 0) + break; + if (ret == 0) + return ret; + dataoff += *matchoff; + } + + if (in_header) + *in_header = 1; + return 1; +} + +/* Locate a SIP header, parse the URI and return the offset and length of + * the address as well as the address and port themselves. A stream of + * headers can be parsed by handing in a non-NULL datalen and in_header + * pointer. + */ +int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr, + unsigned int *dataoff, unsigned int datalen, + enum sip_header_types type, int *in_header, + unsigned int *matchoff, unsigned int *matchlen, + union nf_inet_addr *addr, __be16 *port) +{ + const char *c, *limit = dptr + datalen; + unsigned int p; + int ret; + + ret = ct_sip_walk_headers(ct, dptr, dataoff ? *dataoff : 0, datalen, + type, in_header, matchoff, matchlen); + WARN_ON(ret < 0); + if (ret == 0) + return ret; + + if (!parse_addr(ct, dptr + *matchoff, &c, addr, limit)) + return -1; + if (*c == ':') { + c++; + p = simple_strtoul(c, (char **)&c, 10); + if (p < 1024 || p > 65535) + return -1; + *port = htons(p); + } else + *port = htons(SIP_PORT); + + if (dataoff) + *dataoff = c - dptr; + return 1; +} +EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri); + /* SDP header parsing: a SDP session description contains an ordered set of * headers, starting with a section containing general session parameters, * optionally followed by multiple media descriptions. |