3 files changed, 151 insertions, 168 deletions
diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 480b26f40ce4..ccc701422963 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -5,14 +5,6 @@
 #define SIP_PORT        5060
 #define SIP_TIMEOUT     3600
-enum sip_header_pos {
-        POS_FROM,
-        POS_TO,
-        POS_VIA,
-        POS_CONTACT,
-        POS_CONTENT,
-};
 struct sip_header {
        const char      *name;
        const char      *cname;
@@ -36,9 +28,20 @@ struct sip_header {
        .match_len      = (__match),                                    \
 }
+#define SIP_HDR(__name, __cname, __search, __match) \
+        __SIP_HDR(__name, __cname, __search, __match)
 #define SDP_HDR(__name, __search, __match) \
        __SIP_HDR(__name, NULL, __search, __match)
+enum sip_header_types {
+        SIP_HDR_FROM,
+        SIP_HDR_TO,
+        SIP_HDR_CONTACT,
+        SIP_HDR_VIA,
+        SIP_HDR_CONTENT_LENGTH,
+};
 enum sdp_header_types {
        SDP_HDR_UNSPEC,
        SDP_HDR_VERSION,
@@ -60,13 +63,10 @@ extern unsigned int (*nf_nat_sdp_hook)(struct sk_buff *skb,
 extern int ct_sip_parse_request(const struct nf_conn *ct,
                                const char *dptr, unsigned int datalen,
                                unsigned int *matchoff, unsigned int *matchlen);
-extern int ct_sip_get_info(const struct nf_conn *ct, const char *dptr,
+extern int ct_sip_get_header(const struct nf_conn *ct, const char *dptr,
-                           size_t dlen, unsigned int *matchoff,
+                             unsigned int dataoff, unsigned int datalen,
-                           unsigned int *matchlen, enum sip_header_pos pos);
+                             enum sip_header_types type,
-extern int ct_sip_lnlen(const char *line, const char *limit);
+                             unsigned int *matchoff, unsigned int *matchlen);
-extern const char *ct_sip_search(const char *needle, const char *haystack,
-                                 size_t needle_len, size_t haystack_len,
-                                 int case_sensitive);
 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/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index 60151b5901a5..c13e43862361 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -108,14 +108,14 @@ static int map_addr(struct sk_buff *skb,
 static int map_sip_addr(struct sk_buff *skb,
                        const char **dptr, unsigned int *datalen,
-                        enum sip_header_pos pos, struct addr_map *map)
+                        enum sip_header_types type, struct addr_map *map)
 {
        enum ip_conntrack_info ctinfo;
        struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
        unsigned int matchlen, matchoff;
-        if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff, &matchlen,
+        if (ct_sip_get_header(ct, *dptr, 0, *datalen, type,
-                            pos) <= 0)
+                              &matchoff, &matchlen) <= 0)
                return 1;
        return map_addr(skb, dptr, datalen, matchoff, matchlen, map);
 }
@@ -141,10 +141,10 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
                        return NF_DROP;
        }
-        if (!map_sip_addr(skb, dptr, datalen, POS_FROM, &map) ||
+        if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM, &map) ||
-            !map_sip_addr(skb, dptr, datalen, POS_TO, &map) ||
+            !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO, &map) ||
-            !map_sip_addr(skb, dptr, datalen, POS_VIA, &map) ||
+            !map_sip_addr(skb, dptr, datalen, SIP_HDR_VIA, &map) ||
-            !map_sip_addr(skb, dptr, datalen, POS_CONTACT, &map))
+            !map_sip_addr(skb, dptr, datalen, SIP_HDR_CONTACT, &map))
                return NF_DROP;
        return NF_ACCEPT;
 }
@@ -166,8 +166,8 @@ static int mangle_content_len(struct sk_buff *skb,
        c_len = *datalen - matchoff + strlen("v=");
        /* Now, update SDP length */
-        if (ct_sip_get_info(ct, *dptr, *datalen, &matchoff, &matchlen,
+        if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CONTENT_LENGTH,
-                            POS_CONTENT) <= 0)
+                              &matchoff, &matchlen) <= 0)
                return 0;
        buflen = sprintf(buffer, "%u", c_len);
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index bb4396155681..cbc91598acee 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -47,109 +47,6 @@ unsigned int (*nf_nat_sdp_hook)(struct sk_buff *skb,
                                struct nf_conntrack_expect *exp) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sdp_hook);
-static int digits_len(const struct nf_conn *, const char *, const char *, int *);
-static int epaddr_len(const struct nf_conn *, const char *, const char *, int *);
-static int skp_digits_len(const struct nf_conn *, const char *, const char *, int *);
-static int skp_epaddr_len(const struct nf_conn *, const char *, const char *, int *);
-struct sip_header_nfo {
-        const char      *lname;
-        const char      *sname;
-        const char      *ln_str;
-        size_t          lnlen;
-        size_t          snlen;
-        size_t          ln_strlen;
-        int             case_sensitive;
-        int             (*match_len)(const struct nf_conn *, const char *,
-                                     const char *, int *);
-};
-static const struct sip_header_nfo ct_sip_hdrs[] = {
-        [POS_FROM] = {          /* SIP From header */
-                .lname          = "From:",
-                .lnlen          = sizeof("From:") - 1,
-                .sname          = "\r\nf:",
-                .snlen          = sizeof("\r\nf:") - 1,
-                .ln_str         = "sip:",
-                .ln_strlen      = sizeof("sip:") - 1,
-                .match_len      = skp_epaddr_len,
-        },
-        [POS_TO] = {            /* SIP To header */
-                .lname          = "To:",
-                .lnlen          = sizeof("To:") - 1,
-                .sname          = "\r\nt:",
-                .snlen          = sizeof("\r\nt:") - 1,
-                .ln_str         = "sip:",
-                .ln_strlen      = sizeof("sip:") - 1,
-                .match_len      = skp_epaddr_len
-        },
-        [POS_VIA] = {           /* SIP Via header */
-                .lname          = "Via:",
-                .lnlen          = sizeof("Via:") - 1,
-                .sname          = "\r\nv:",
-                .snlen          = sizeof("\r\nv:") - 1, /* rfc3261 "\r\n" */
-                .ln_str         = "UDP ",
-                .ln_strlen      = sizeof("UDP ") - 1,
-                .match_len      = epaddr_len,
-        },
-        [POS_CONTACT] = {       /* SIP Contact header */
-                .lname          = "Contact:",
-                .lnlen          = sizeof("Contact:") - 1,
-                .sname          = "\r\nm:",
-                .snlen          = sizeof("\r\nm:") - 1,
-                .ln_str         = "sip:",
-                .ln_strlen      = sizeof("sip:") - 1,
-                .match_len      = skp_epaddr_len
-        },
-        [POS_CONTENT] = {       /* SIP Content length header */
-                .lname          = "Content-Length:",
-                .lnlen          = sizeof("Content-Length:") - 1,
-                .sname          = "\r\nl:",
-                .snlen          = sizeof("\r\nl:") - 1,
-                .ln_str         = ":",
-                .ln_strlen      = sizeof(":") - 1,
-                .match_len      = skp_digits_len
-        },
-};
-/* get line length until first CR or LF seen. */
-int ct_sip_lnlen(const char *line, const char *limit)
-{
-        const char *k = line;
-        while ((line < limit) && (*line == '\r' || *line == '\n'))
-                line++;
-        while (line < limit) {
-                if (*line == '\r' || *line == '\n')
-                        break;
-                line++;
-        }
-        return line - k;
-}
-EXPORT_SYMBOL_GPL(ct_sip_lnlen);
-/* Linear string search, case sensitive. */
-const char *ct_sip_search(const char *needle, const char *haystack,
-                          size_t needle_len, size_t haystack_len,
-                          int case_sensitive)
-{
-        const char *limit = haystack + (haystack_len - needle_len);
-        while (haystack < limit) {
-                if (case_sensitive) {
-                        if (strncmp(haystack, needle, needle_len) == 0)
-                                return haystack;
-                } else {
-                        if (strnicmp(haystack, needle, needle_len) == 0)
-                                return haystack;
-                }
-                haystack++;
-        }
-        return NULL;
-}
-EXPORT_SYMBOL_GPL(ct_sip_search);
 static int string_len(const struct nf_conn *ct, const char *dptr,
                      const char *limit, int *shift)
 {
@@ -173,16 +70,6 @@ static int digits_len(const struct nf_conn *ct, const char *dptr,
        return len;
 }
-/* get digits length, skipping blank spaces. */
-static int skp_digits_len(const struct nf_conn *ct, const char *dptr,
-                          const char *limit, int *shift)
-{
-        for (; dptr < limit && *dptr == ' '; dptr++)
-                (*shift)++;
-        return digits_len(ct, dptr, limit, shift);
-}
 static int parse_addr(const struct nf_conn *ct, const char *cp,
                      const char **endp, union nf_inet_addr *addr,
                      const char *limit)
@@ -294,50 +181,146 @@ int ct_sip_parse_request(const struct nf_conn *ct,
 }
 EXPORT_SYMBOL_GPL(ct_sip_parse_request);
-/* Returns 0 if not found, -1 error parsing. */
+/* SIP header parsing: SIP headers are located at the beginning of a line, but
-int ct_sip_get_info(const struct nf_conn *ct,
+ * may span several lines, in which case the continuation lines begin with a
-                    const char *dptr, size_t dlen,
+ * whitespace character. RFC 2543 allows lines to be terminated with CR, LF or
-                    unsigned int *matchoff,
+ * CRLF, RFC 3261 allows only CRLF, we support both.
-                    unsigned int *matchlen,
+ *
-                    enum sip_header_pos pos)
+ * Headers are followed by (optionally) whitespace, a colon, again (optionally)
+ * 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.
+ */
+static const struct sip_header ct_sip_hdrs[] = {
+        [SIP_HDR_FROM]                  = SIP_HDR("From", "f", "sip:", skp_epaddr_len),
+        [SIP_HDR_TO]                    = SIP_HDR("To", "t", "sip:", skp_epaddr_len),
+        [SIP_HDR_CONTACT]               = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len),
+        [SIP_HDR_VIA]                   = SIP_HDR("Via", "v", "UDP ", epaddr_len),
+        [SIP_HDR_CONTENT_LENGTH]        = SIP_HDR("Content-Length", "l", NULL, digits_len),
+};
+static const char *sip_follow_continuation(const char *dptr, const char *limit)
 {
-        const struct sip_header_nfo *hnfo = &ct_sip_hdrs[pos];
+        /* Walk past newline */
-        const char *limit, *aux, *k = dptr;
+        if (++dptr >= limit)
-        int shift = 0;
+                return NULL;
+        /* Skip '\n' in CR LF */
+        if (*(dptr - 1) == '\r' && *dptr == '\n') {
+                if (++dptr >= limit)
+                        return NULL;
+        }
+        /* Continuation line? */
+        if (*dptr != ' ' && *dptr != '\t')
+                return NULL;
+        /* skip leading whitespace */
+        for (; dptr < limit; dptr++) {
+                if (*dptr != ' ' && *dptr != '\t')
+                        break;
+        }
+        return dptr;
+}
+static const char *sip_skip_whitespace(const char *dptr, const char *limit)
+{
+        for (; dptr < limit; dptr++) {
+                if (*dptr == ' ')
+                        continue;
+                if (*dptr != '\r' && *dptr != '\n')
+                        break;
+                dptr = sip_follow_continuation(dptr, limit);
+                if (dptr == NULL)
+                        return NULL;
+        }
+        return dptr;
+}
-        limit = dptr + (dlen - hnfo->lnlen);
+/* Search within a SIP header value, dealing with continuation lines */
+static const char *ct_sip_header_search(const char *dptr, const char *limit,
+                                        const char *needle, unsigned int len)
+{
+        for (limit -= len; dptr < limit; dptr++) {
+                if (*dptr == '\r' || *dptr == '\n') {
+                        dptr = sip_follow_continuation(dptr, limit);
+                        if (dptr == NULL)
+                                break;
+                        continue;
+                }
-        while (dptr < limit) {
+                if (strnicmp(dptr, needle, len) == 0)
-                if ((strncmp(dptr, hnfo->lname, hnfo->lnlen) != 0) &&
+                        return dptr;
-                    (hnfo->sname == NULL ||
+        }
-                     strncmp(dptr, hnfo->sname, hnfo->snlen) != 0)) {
+        return NULL;
-                        dptr++;
+}
+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)
+{
+        const struct sip_header *hdr = &ct_sip_hdrs[type];
+        const char *start = dptr, *limit = dptr + datalen;
+        int shift = 0;
+        for (dptr += dataoff; dptr < limit; dptr++) {
+                /* Find beginning of line */
+                if (*dptr != '\r' && *dptr != '\n')
                        continue;
+                if (++dptr >= limit)
+                        break;
+                if (*(dptr - 1) == '\r' && *dptr == '\n') {
+                        if (++dptr >= limit)
+                                break;
                }
-                aux = ct_sip_search(hnfo->ln_str, dptr, hnfo->ln_strlen,
-                                    ct_sip_lnlen(dptr, limit),
+                /* Skip continuation lines */
-                                    hnfo->case_sensitive);
+                if (*dptr == ' ' || *dptr == '\t')
-                if (!aux) {
+                        continue;
-                        pr_debug("'%s' not found in '%s'.\n", hnfo->ln_str,
-                                 hnfo->lname);
+                /* Find header. Compact headers must be followed by a
-                        return -1;
+                 * non-alphabetic character to avoid mismatches. */
+                if (limit - dptr >= hdr->len &&
+                    strnicmp(dptr, hdr->name, hdr->len) == 0)
+                        dptr += hdr->len;
+                else if (hdr->cname && limit - dptr >= hdr->clen + 1 &&
+                         strnicmp(dptr, hdr->cname, hdr->clen) == 0 &&
+                         !isalpha(*(dptr + hdr->clen + 1)))
+                        dptr += hdr->clen;
+                else
+                        continue;
+                /* Find and skip colon */
+                dptr = sip_skip_whitespace(dptr, limit);
+                if (dptr == NULL)
+                        break;
+                if (*dptr != ':' || ++dptr >= limit)
+                        break;
+                /* Skip whitespace after colon */
+                dptr = sip_skip_whitespace(dptr, limit);
+                if (dptr == NULL)
+                        break;
+                *matchoff = dptr - start;
+                if (hdr->search) {
+                        dptr = ct_sip_header_search(dptr, limit, hdr->search,
+                                                    hdr->slen);
+                        if (!dptr)
+                                return -1;
+                        dptr += hdr->slen;
                }
-                aux += hnfo->ln_strlen;
-                *matchlen = hnfo->match_len(ct, aux, limit, &shift);
+                *matchlen = hdr->match_len(ct, dptr, limit, &shift);
                if (!*matchlen)
                        return -1;
+                *matchoff = dptr - start + shift;
-                *matchoff = (aux - k) + shift;
-                pr_debug("%s match succeeded! - len: %u\n", hnfo->lname,
-                         *matchlen);
                return 1;
        }
-        pr_debug("%s header not found.\n", hnfo->lname);
        return 0;
 }
-EXPORT_SYMBOL_GPL(ct_sip_get_info);
+EXPORT_SYMBOL_GPL(ct_sip_get_header);
 /* SDP header parsing: a SDP session description contains an ordered set of
 * headers, starting with a section containing general session parameters,

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h index 480b26f40ce4..ccc701422963 100644 --- a/include/linux/netfilter/nf_conntrack_sip.h +++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -5,14 +5,6 @@
5	#define SIP_PORT 5060	5	#define SIP_PORT 5060
6	#define SIP_TIMEOUT 3600	6	#define SIP_TIMEOUT 3600
7		7
8	enum sip_header_pos {
9	POS_FROM,
10	POS_TO,
11	POS_VIA,
12	POS_CONTACT,
13	POS_CONTENT,
14	};
15
16	struct sip_header {	8	struct sip_header {
17	const char *name;	9	const char *name;
18	const char *cname;	10	const char *cname;
@@ -36,9 +28,20 @@ struct sip_header {
36	.match_len = (__match), \	28	.match_len = (__match), \
37	}	29	}
38		30
		31	#define SIP_HDR(__name, __cname, __search, __match) \
		32	__SIP_HDR(__name, __cname, __search, __match)
		33
39	#define SDP_HDR(__name, __search, __match) \	34	#define SDP_HDR(__name, __search, __match) \
40	__SIP_HDR(__name, NULL, __search, __match)	35	__SIP_HDR(__name, NULL, __search, __match)
41		36
		37	enum sip_header_types {
		38	SIP_HDR_FROM,
		39	SIP_HDR_TO,
		40	SIP_HDR_CONTACT,
		41	SIP_HDR_VIA,
		42	SIP_HDR_CONTENT_LENGTH,
		43	};
		44
42	enum sdp_header_types {	45	enum sdp_header_types {
43	SDP_HDR_UNSPEC,	46	SDP_HDR_UNSPEC,
44	SDP_HDR_VERSION,	47	SDP_HDR_VERSION,
@@ -60,13 +63,10 @@ extern unsigned int (nf_nat_sdp_hook)(struct sk_buff skb,
60	extern int ct_sip_parse_request(const struct nf_conn *ct,	63	extern int ct_sip_parse_request(const struct nf_conn *ct,
61	const char *dptr, unsigned int datalen,	64	const char *dptr, unsigned int datalen,
62	unsigned int matchoff, unsigned int matchlen);	65	unsigned int matchoff, unsigned int matchlen);
63	extern int ct_sip_get_info(const struct nf_conn ct, const char dptr,	66	extern int ct_sip_get_header(const struct nf_conn ct, const char dptr,
64	size_t dlen, unsigned int *matchoff,	67	unsigned int dataoff, unsigned int datalen,
65	unsigned int *matchlen, enum sip_header_pos pos);	68	enum sip_header_types type,
66	extern int ct_sip_lnlen(const char line, const char limit);	69	unsigned int matchoff, unsigned int matchlen);
67	extern const char ct_sip_search(const char needle, const char *haystack,
68	size_t needle_len, size_t haystack_len,
69	int case_sensitive);
70		70
71	extern int ct_sip_get_sdp_header(const struct nf_conn ct, const char dptr,	71	extern int ct_sip_get_sdp_header(const struct nf_conn ct, const char dptr,
72	unsigned int dataoff, unsigned int datalen,	72	unsigned int dataoff, unsigned int datalen,


diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c index 60151b5901a5..c13e43862361 100644 --- a/net/ipv4/netfilter/nf_nat_sip.c +++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -108,14 +108,14 @@ static int map_addr(struct sk_buff *skb,
108		108
109	static int map_sip_addr(struct sk_buff *skb,	109	static int map_sip_addr(struct sk_buff *skb,
110	const char *dptr, unsigned int datalen,	110	const char *dptr, unsigned int datalen,
111	enum sip_header_pos pos, struct addr_map *map)	111	enum sip_header_types type, struct addr_map *map)
112	{	112	{
113	enum ip_conntrack_info ctinfo;	113	enum ip_conntrack_info ctinfo;
114	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);	114	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
115	unsigned int matchlen, matchoff;	115	unsigned int matchlen, matchoff;
116		116
117	if (ct_sip_get_info(ct, dptr, datalen, &matchoff, &matchlen,	117	if (ct_sip_get_header(ct, dptr, 0, datalen, type,
118	pos) <= 0)	118	&matchoff, &matchlen) <= 0)
119	return 1;	119	return 1;
120	return map_addr(skb, dptr, datalen, matchoff, matchlen, map);	120	return map_addr(skb, dptr, datalen, matchoff, matchlen, map);
121	}	121	}
@@ -141,10 +141,10 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
141	return NF_DROP;	141	return NF_DROP;
142	}	142	}
143		143
144	if (!map_sip_addr(skb, dptr, datalen, POS_FROM, &map) \|\|	144	if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM, &map) \|\|
145	!map_sip_addr(skb, dptr, datalen, POS_TO, &map) \|\|	145	!map_sip_addr(skb, dptr, datalen, SIP_HDR_TO, &map) \|\|
146	!map_sip_addr(skb, dptr, datalen, POS_VIA, &map) \|\|	146	!map_sip_addr(skb, dptr, datalen, SIP_HDR_VIA, &map) \|\|
147	!map_sip_addr(skb, dptr, datalen, POS_CONTACT, &map))	147	!map_sip_addr(skb, dptr, datalen, SIP_HDR_CONTACT, &map))
148	return NF_DROP;	148	return NF_DROP;
149	return NF_ACCEPT;	149	return NF_ACCEPT;
150	}	150	}
@@ -166,8 +166,8 @@ static int mangle_content_len(struct sk_buff *skb,
166	c_len = *datalen - matchoff + strlen("v=");	166	c_len = *datalen - matchoff + strlen("v=");
167		167
168	/* Now, update SDP length */	168	/* Now, update SDP length */
169	if (ct_sip_get_info(ct, dptr, datalen, &matchoff, &matchlen,	169	if (ct_sip_get_header(ct, dptr, 0, datalen, SIP_HDR_CONTENT_LENGTH,
170	POS_CONTENT) <= 0)	170	&matchoff, &matchlen) <= 0)
171	return 0;	171	return 0;
172		172
173	buflen = sprintf(buffer, "%u", c_len);	173	buflen = sprintf(buffer, "%u", c_len);


diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index bb4396155681..cbc91598acee 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c
@@ -47,109 +47,6 @@ unsigned int (nf_nat_sdp_hook)(struct sk_buff skb,
47	struct nf_conntrack_expect *exp) __read_mostly;	47	struct nf_conntrack_expect *exp) __read_mostly;
48	EXPORT_SYMBOL_GPL(nf_nat_sdp_hook);	48	EXPORT_SYMBOL_GPL(nf_nat_sdp_hook);
49		49
50	static int digits_len(const struct nf_conn , const char , const char , int );
51	static int epaddr_len(const struct nf_conn , const char , const char , int );
52	static int skp_digits_len(const struct nf_conn , const char , const char , int );
53	static int skp_epaddr_len(const struct nf_conn , const char , const char , int );
54
55	struct sip_header_nfo {
56	const char *lname;
57	const char *sname;
58	const char *ln_str;
59	size_t lnlen;
60	size_t snlen;
61	size_t ln_strlen;
62	int case_sensitive;
63	int (match_len)(const struct nf_conn , const char *,
64	const char , int );
65	};
66
67	static const struct sip_header_nfo ct_sip_hdrs[] = {
68	[POS_FROM] = { /* SIP From header */
69	.lname = "From:",
70	.lnlen = sizeof("From:") - 1,
71	.sname = "\r\nf:",
72	.snlen = sizeof("\r\nf:") - 1,
73	.ln_str = "sip:",
74	.ln_strlen = sizeof("sip:") - 1,
75	.match_len = skp_epaddr_len,
76	},
77	[POS_TO] = { /* SIP To header */
78	.lname = "To:",
79	.lnlen = sizeof("To:") - 1,
80	.sname = "\r\nt:",
81	.snlen = sizeof("\r\nt:") - 1,
82	.ln_str = "sip:",
83	.ln_strlen = sizeof("sip:") - 1,
84	.match_len = skp_epaddr_len
85	},
86	[POS_VIA] = { /* SIP Via header */
87	.lname = "Via:",
88	.lnlen = sizeof("Via:") - 1,
89	.sname = "\r\nv:",
90	.snlen = sizeof("\r\nv:") - 1, /* rfc3261 "\r\n" */
91	.ln_str = "UDP ",
92	.ln_strlen = sizeof("UDP ") - 1,
93	.match_len = epaddr_len,
94	},
95	[POS_CONTACT] = { /* SIP Contact header */
96	.lname = "Contact:",
97	.lnlen = sizeof("Contact:") - 1,
98	.sname = "\r\nm:",
99	.snlen = sizeof("\r\nm:") - 1,
100	.ln_str = "sip:",
101	.ln_strlen = sizeof("sip:") - 1,
102	.match_len = skp_epaddr_len
103	},
104	[POS_CONTENT] = { /* SIP Content length header */
105	.lname = "Content-Length:",
106	.lnlen = sizeof("Content-Length:") - 1,
107	.sname = "\r\nl:",
108	.snlen = sizeof("\r\nl:") - 1,
109	.ln_str = ":",
110	.ln_strlen = sizeof(":") - 1,
111	.match_len = skp_digits_len
112	},
113	};
114
115	/* get line length until first CR or LF seen. */
116	int ct_sip_lnlen(const char line, const char limit)
117	{
118	const char *k = line;
119
120	while ((line < limit) && (line == '\r' \|\| line == '\n'))
121	line++;
122
123	while (line < limit) {
124	if (line == '\r' \|\| line == '\n')
125	break;
126	line++;
127	}
128	return line - k;
129	}
130	EXPORT_SYMBOL_GPL(ct_sip_lnlen);
131
132	/* Linear string search, case sensitive. */
133	const char ct_sip_search(const char needle, const char *haystack,
134	size_t needle_len, size_t haystack_len,
135	int case_sensitive)
136	{
137	const char *limit = haystack + (haystack_len - needle_len);
138
139	while (haystack < limit) {
140	if (case_sensitive) {
141	if (strncmp(haystack, needle, needle_len) == 0)
142	return haystack;
143	} else {
144	if (strnicmp(haystack, needle, needle_len) == 0)
145	return haystack;
146	}
147	haystack++;
148	}
149	return NULL;
150	}
151	EXPORT_SYMBOL_GPL(ct_sip_search);
152
153	static int string_len(const struct nf_conn ct, const char dptr,	50	static int string_len(const struct nf_conn ct, const char dptr,
154	const char limit, int shift)	51	const char limit, int shift)
155	{	52	{
@@ -173,16 +70,6 @@ static int digits_len(const struct nf_conn ct, const char dptr,
173	return len;	70	return len;
174	}	71	}
175		72
176	/* get digits length, skipping blank spaces. */
177	static int skp_digits_len(const struct nf_conn ct, const char dptr,
178	const char limit, int shift)
179	{
180	for (; dptr < limit && *dptr == ' '; dptr++)
181	(*shift)++;
182
183	return digits_len(ct, dptr, limit, shift);
184	}
185
186	static int parse_addr(const struct nf_conn ct, const char cp,	73	static int parse_addr(const struct nf_conn ct, const char cp,
187	const char *endp, union nf_inet_addr addr,	74	const char *endp, union nf_inet_addr addr,
188	const char *limit)	75	const char *limit)
@@ -294,50 +181,146 @@ int ct_sip_parse_request(const struct nf_conn *ct,
294	}	181	}
295	EXPORT_SYMBOL_GPL(ct_sip_parse_request);	182	EXPORT_SYMBOL_GPL(ct_sip_parse_request);
296		183
297	/* Returns 0 if not found, -1 error parsing. */	184	/* SIP header parsing: SIP headers are located at the beginning of a line, but
298	int ct_sip_get_info(const struct nf_conn *ct,	185	* may span several lines, in which case the continuation lines begin with a
299	const char *dptr, size_t dlen,	186	* whitespace character. RFC 2543 allows lines to be terminated with CR, LF or
300	unsigned int *matchoff,	187	* CRLF, RFC 3261 allows only CRLF, we support both.
301	unsigned int *matchlen,	188	*
302	enum sip_header_pos pos)	189	* Headers are followed by (optionally) whitespace, a colon, again (optionally)
		190	* whitespace and the values. Whitespace in this context means any amount of
		191	* tabs, spaces and continuation lines, which are treated as a single whitespace
		192	* character.
		193	*/
		194	static const struct sip_header ct_sip_hdrs[] = {
		195	[SIP_HDR_FROM] = SIP_HDR("From", "f", "sip:", skp_epaddr_len),
		196	[SIP_HDR_TO] = SIP_HDR("To", "t", "sip:", skp_epaddr_len),
		197	[SIP_HDR_CONTACT] = SIP_HDR("Contact", "m", "sip:", skp_epaddr_len),
		198	[SIP_HDR_VIA] = SIP_HDR("Via", "v", "UDP ", epaddr_len),
		199	[SIP_HDR_CONTENT_LENGTH] = SIP_HDR("Content-Length", "l", NULL, digits_len),
		200	};
		201
		202	static const char sip_follow_continuation(const char dptr, const char *limit)
303	{	203	{
304	const struct sip_header_nfo *hnfo = &ct_sip_hdrs[pos];	204	/* Walk past newline */
305	const char limit, aux, *k = dptr;	205	if (++dptr >= limit)
306	int shift = 0;	206	return NULL;
		207
		208	/* Skip '\n' in CR LF */
		209	if ((dptr - 1) == '\r' && dptr == '\n') {
		210	if (++dptr >= limit)
		211	return NULL;
		212	}
		213
		214	/* Continuation line? */
		215	if (dptr != ' ' && dptr != '\t')
		216	return NULL;
		217
		218	/* skip leading whitespace */
		219	for (; dptr < limit; dptr++) {
		220	if (dptr != ' ' && dptr != '\t')
		221	break;
		222	}
		223	return dptr;
		224	}
		225
		226	static const char sip_skip_whitespace(const char dptr, const char *limit)
		227	{
		228	for (; dptr < limit; dptr++) {
		229	if (*dptr == ' ')
		230	continue;
		231	if (dptr != '\r' && dptr != '\n')
		232	break;
		233	dptr = sip_follow_continuation(dptr, limit);
		234	if (dptr == NULL)
		235	return NULL;
		236	}
		237	return dptr;
		238	}
307		239
308	limit = dptr + (dlen - hnfo->lnlen);	240	/* Search within a SIP header value, dealing with continuation lines */
		241	static const char ct_sip_header_search(const char dptr, const char *limit,
		242	const char *needle, unsigned int len)
		243	{
		244	for (limit -= len; dptr < limit; dptr++) {
		245	if (dptr == '\r' \|\| dptr == '\n') {
		246	dptr = sip_follow_continuation(dptr, limit);
		247	if (dptr == NULL)
		248	break;
		249	continue;
		250	}
309		251
310	while (dptr < limit) {	252	if (strnicmp(dptr, needle, len) == 0)
311	if ((strncmp(dptr, hnfo->lname, hnfo->lnlen) != 0) &&	253	return dptr;
312	(hnfo->sname == NULL \|\|	254	}
313	strncmp(dptr, hnfo->sname, hnfo->snlen) != 0)) {	255	return NULL;
314	dptr++;	256	}
		257
		258	int ct_sip_get_header(const struct nf_conn ct, const char dptr,
		259	unsigned int dataoff, unsigned int datalen,
		260	enum sip_header_types type,
		261	unsigned int matchoff, unsigned int matchlen)
		262	{
		263	const struct sip_header *hdr = &ct_sip_hdrs[type];
		264	const char start = dptr, limit = dptr + datalen;
		265	int shift = 0;
		266
		267	for (dptr += dataoff; dptr < limit; dptr++) {
		268	/* Find beginning of line */
		269	if (dptr != '\r' && dptr != '\n')
315	continue;	270	continue;
		271	if (++dptr >= limit)
		272	break;
		273	if ((dptr - 1) == '\r' && dptr == '\n') {
		274	if (++dptr >= limit)
		275	break;
316	}	276	}
317	aux = ct_sip_search(hnfo->ln_str, dptr, hnfo->ln_strlen,	277
318	ct_sip_lnlen(dptr, limit),	278	/* Skip continuation lines */
319	hnfo->case_sensitive);	279	if (dptr == ' ' \|\| dptr == '\t')
320	if (!aux) {	280	continue;
321	pr_debug("'%s' not found in '%s'.\n", hnfo->ln_str,	281
322	hnfo->lname);	282	/* Find header. Compact headers must be followed by a
323	return -1;	283	* non-alphabetic character to avoid mismatches. */
		284	if (limit - dptr >= hdr->len &&
		285	strnicmp(dptr, hdr->name, hdr->len) == 0)
		286	dptr += hdr->len;
		287	else if (hdr->cname && limit - dptr >= hdr->clen + 1 &&
		288	strnicmp(dptr, hdr->cname, hdr->clen) == 0 &&
		289	!isalpha(*(dptr + hdr->clen + 1)))
		290	dptr += hdr->clen;
		291	else
		292	continue;
		293
		294	/* Find and skip colon */
		295	dptr = sip_skip_whitespace(dptr, limit);
		296	if (dptr == NULL)
		297	break;
		298	if (*dptr != ':' \|\| ++dptr >= limit)
		299	break;
		300
		301	/* Skip whitespace after colon */
		302	dptr = sip_skip_whitespace(dptr, limit);
		303	if (dptr == NULL)
		304	break;
		305
		306	*matchoff = dptr - start;
		307	if (hdr->search) {
		308	dptr = ct_sip_header_search(dptr, limit, hdr->search,
		309	hdr->slen);
		310	if (!dptr)
		311	return -1;
		312	dptr += hdr->slen;
324	}	313	}
325	aux += hnfo->ln_strlen;
326		314
327	*matchlen = hnfo->match_len(ct, aux, limit, &shift);	315	*matchlen = hdr->match_len(ct, dptr, limit, &shift);
328	if (!*matchlen)	316	if (!*matchlen)
329	return -1;	317	return -1;
330		318	*matchoff = dptr - start + shift;
331	*matchoff = (aux - k) + shift;
332
333	pr_debug("%s match succeeded! - len: %u\n", hnfo->lname,
334	*matchlen);
335	return 1;	319	return 1;
336	}	320	}
337	pr_debug("%s header not found.\n", hnfo->lname);
338	return 0;	321	return 0;
339	}	322	}
340	EXPORT_SYMBOL_GPL(ct_sip_get_info);	323	EXPORT_SYMBOL_GPL(ct_sip_get_header);
341		324
342	/* SDP header parsing: a SDP session description contains an ordered set of	325	/* SDP header parsing: a SDP session description contains an ordered set of
343	* headers, starting with a section containing general session parameters,	326	* headers, starting with a section containing general session parameters,