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[NETFILTER]: sip conntrack: do case insensitive SIP header search
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SIP headers are generally case-insensitive, only SDP headers are
case sensitive.

Signed-off-by: Patrick McHardy <kaber@trash.net>
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Patrick McHardy authored and David S. Miller committed Dec 3, 2006
1 parent 9d5b8ba commit 40883e8
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Showing 3 changed files with 22 additions and 8 deletions.
3 changes: 2 additions & 1 deletion include/linux/netfilter_ipv4/ip_conntrack_sip.h
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@ extern int ct_sip_get_info(const char *dptr, size_t dlen,
enum sip_header_pos pos);
extern int ct_sip_lnlen(const char *line, const char *limit);
extern const char *ct_sip_search(const char *needle, const char *haystack,
size_t needle_len, size_t haystack_len);
size_t needle_len, size_t haystack_len,
int case_sensitive);
#endif /* __KERNEL__ */
#endif /* __IP_CONNTRACK_SIP_H__ */
20 changes: 16 additions & 4 deletions net/ipv4/netfilter/ip_conntrack_sip.c
Original file line number Diff line number Diff line change
Expand Up @@ -64,6 +64,7 @@ struct sip_header_nfo {
size_t lnlen;
size_t snlen;
size_t ln_strlen;
int case_sensitive;
int (*match_len)(const char *, const char *, int *);
};

Expand Down Expand Up @@ -105,6 +106,7 @@ static struct sip_header_nfo ct_sip_hdrs[] = {
.match_len = skp_digits_len
},
[POS_MEDIA] = { /* SDP media info */
.case_sensitive = 1,
.lname = "\nm=",
.lnlen = sizeof("\nm=") - 1,
.sname = "\rm=",
Expand All @@ -114,6 +116,7 @@ static struct sip_header_nfo ct_sip_hdrs[] = {
.match_len = digits_len
},
[POS_OWNER] = { /* SDP owner address*/
.case_sensitive = 1,
.lname = "\no=",
.lnlen = sizeof("\no=") - 1,
.sname = "\ro=",
Expand All @@ -123,6 +126,7 @@ static struct sip_header_nfo ct_sip_hdrs[] = {
.match_len = epaddr_len
},
[POS_CONNECTION] = { /* SDP connection info */
.case_sensitive = 1,
.lname = "\nc=",
.lnlen = sizeof("\nc=") - 1,
.sname = "\rc=",
Expand All @@ -132,6 +136,7 @@ static struct sip_header_nfo ct_sip_hdrs[] = {
.match_len = epaddr_len
},
[POS_SDP_HEADER] = { /* SDP version header */
.case_sensitive = 1,
.lname = "\nv=",
.lnlen = sizeof("\nv=") - 1,
.sname = "\rv=",
Expand Down Expand Up @@ -161,13 +166,19 @@ 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)
size_t needle_len, size_t haystack_len,
int case_sensitive)
{
const char *limit = haystack + (haystack_len - needle_len);

while (haystack <= limit) {
if (memcmp(haystack, needle, needle_len) == 0)
return haystack;
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;
Expand Down Expand Up @@ -280,7 +291,8 @@ int ct_sip_get_info(const char *dptr, size_t dlen,
continue;
}
aux = ct_sip_search(hnfo->ln_str, dptr, hnfo->ln_strlen,
ct_sip_lnlen(dptr, limit));
ct_sip_lnlen(dptr, limit),
hnfo->case_sensitive);
if (!aux) {
DEBUGP("'%s' not found in '%s'.\n", hnfo->ln_str,
hnfo->lname);
Expand Down
7 changes: 4 additions & 3 deletions net/ipv4/netfilter/ip_nat_sip.c
Original file line number Diff line number Diff line change
Expand Up @@ -87,14 +87,15 @@ static unsigned int ip_nat_sip(struct sk_buff **pskb,
buffer, bufflen, POS_VIA))
return 0;

/* This search should ignore case, but later.. */
aux = ct_sip_search("CSeq:", *dptr, sizeof("CSeq:") - 1,
(*pskb)->len - dataoff);
(*pskb)->len - dataoff, 0);
if (!aux)
return 0;

if (!ct_sip_search("REGISTER", aux, sizeof("REGISTER"),
ct_sip_lnlen(aux, *dptr + (*pskb)->len - dataoff)))
ct_sip_lnlen(aux,
*dptr + (*pskb)->len - dataoff),
1))
return 1;

return mangle_sip_packet(pskb, ctinfo, ct, dptr,
Expand Down

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