netfilter: nf_conntrack_sip: Add callid parser

Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>

1 files changed, 39 insertions, 0 deletions

diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 2fd1ea2c1bb3..715ce54d2fc4 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -130,6 +130,44 @@ static int digits_len(const struct nf_conn *ct, const char *dptr,
         return len;
 }
 
+static int iswordc(const char c)
+{
+        if (isalnum(c) || c == '!' || c == '"' || c == '%' ||
+            (c >= '(' && c <= '/') || c == ':' || c == '<' || c == '>' ||
+            c == '?' || (c >= '[' && c <= ']') || c == '_' || c == '`' ||
+            c == '{' || c == '}' || c == '~')
+                return 1;
+        return 0;
+}
+
+static int word_len(const char *dptr, const char *limit)
+{
+        int len = 0;
+        while (dptr < limit && iswordc(*dptr)) {
+                dptr++;
+                len++;
+        }
+        return len;
+}
+
+static int callid_len(const struct nf_conn *ct, const char *dptr,
+                      const char *limit, int *shift)
+{
+        int len, domain_len;
+
+        len = word_len(dptr, limit);
+        dptr += len;
+        if (!len || dptr == limit || *dptr != '@')
+                return len;
+        dptr++;
+        len++;
+
+        domain_len = word_len(dptr, limit);
+        if (!domain_len)
+                return 0;
+        return len + domain_len;
+}
+
 /* get media type + port length */
 static int media_len(const struct nf_conn *ct, const char *dptr,
                      const char *limit, int *shift)
@@ -299,6 +337,7 @@ static const struct sip_header ct_sip_hdrs[] = {
         [SIP_HDR_VIA_TCP]               = SIP_HDR("Via", "v", "TCP ", epaddr_len),
         [SIP_HDR_EXPIRES]               = SIP_HDR("Expires", NULL, NULL, digits_len),
         [SIP_HDR_CONTENT_LENGTH]        = SIP_HDR("Content-Length", "l", NULL, digits_len),
+        [SIP_HDR_CALL_ID]               = SIP_HDR("Call-Id", "i", NULL, callid_len),
 };
 
 static const char *sip_follow_continuation(const char *dptr, const char *limit)