netfilter: nf_ct_helper: better logging for dropped packets
Connection tracking helpers have to drop packets under exceptional
situations. Currently, the user gets the following logging message
in case that happens:
nf_ct_%s: dropping packet ...
However, depending on the helper, there are different reasons why a
packet can be dropped.
This patch modifies the existing code to provide more specific
error message in the scope of each helper to help users to debug
the reason why the packet has been dropped, ie:
nf_ct_%s: dropping packet: reason ...
Thanks to Joe Perches for many formatting suggestions.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
index ce27edf..26c4ae5 100644
--- a/include/net/netfilter/nf_conntrack_helper.h
+++ b/include/net/netfilter/nf_conntrack_helper.h
@@ -100,6 +100,10 @@
void (*expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
};
+__printf(3,4)
+void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct,
+ const char *fmt, ...);
+
void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n);
void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n);
struct nf_ct_helper_expectfn *
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 48990ad..2820aa1 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -100,7 +100,6 @@
enum ip_conntrack_info ctinfo;
const struct nf_conn_help *help;
const struct nf_conntrack_helper *helper;
- unsigned int ret;
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(skb, &ctinfo);
@@ -116,13 +115,8 @@
if (!helper)
return NF_ACCEPT;
- ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
- ct, ctinfo);
- if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
- nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
- "nf_ct_%s: dropping packet", helper->name);
- }
- return ret;
+ return helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
+ ct, ctinfo);
}
static unsigned int ipv4_confirm(unsigned int hooknum,
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index 8a45bb2..2b6c226 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -104,7 +104,6 @@
const struct nf_conn_help *help;
const struct nf_conntrack_helper *helper;
enum ip_conntrack_info ctinfo;
- unsigned int ret;
__be16 frag_off;
int protoff;
u8 nexthdr;
@@ -130,12 +129,7 @@
return NF_ACCEPT;
}
- ret = helper->help(skb, protoff, ct, ctinfo);
- if (ret != NF_ACCEPT && (ret & NF_VERDICT_MASK) != NF_QUEUE) {
- nf_log_packet(NFPROTO_IPV6, hooknum, skb, in, out, NULL,
- "nf_ct_%s: dropping packet", helper->name);
- }
- return ret;
+ return helper->help(skb, protoff, ct, ctinfo);
}
static unsigned int ipv6_confirm(unsigned int hooknum,
diff --git a/net/netfilter/nf_conntrack_amanda.c b/net/netfilter/nf_conntrack_amanda.c
index c514fe6..dbdaa11 100644
--- a/net/netfilter/nf_conntrack_amanda.c
+++ b/net/netfilter/nf_conntrack_amanda.c
@@ -145,6 +145,7 @@
exp = nf_ct_expect_alloc(ct);
if (exp == NULL) {
+ nf_ct_helper_log(skb, ct, "cannot alloc expectation");
ret = NF_DROP;
goto out;
}
@@ -158,8 +159,10 @@
if (nf_nat_amanda && ct->status & IPS_NAT_MASK)
ret = nf_nat_amanda(skb, ctinfo, protoff,
off - dataoff, len, exp);
- else if (nf_ct_expect_related(exp) != 0)
+ else if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct, "cannot add expectation");
ret = NF_DROP;
+ }
nf_ct_expect_put(exp);
}
diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 1ce3bef..62fb8fa 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c
@@ -435,8 +435,8 @@
connection tracking, not packet filtering.
However, it is necessary for accurate tracking in
this case. */
- pr_debug("conntrack_ftp: partial %s %u+%u\n",
- search[dir][i].pattern, ntohl(th->seq), datalen);
+ nf_ct_helper_log(skb, ct, "partial matching of `%s'",
+ search[dir][i].pattern);
ret = NF_DROP;
goto out;
} else if (found == 0) { /* No match */
@@ -450,6 +450,7 @@
exp = nf_ct_expect_alloc(ct);
if (exp == NULL) {
+ nf_ct_helper_log(skb, ct, "cannot alloc expectation");
ret = NF_DROP;
goto out;
}
@@ -500,9 +501,10 @@
protoff, matchoff, matchlen, exp);
else {
/* Can't expect this? Best to drop packet now. */
- if (nf_ct_expect_related(exp) != 0)
+ if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct, "cannot add expectation");
ret = NF_DROP;
- else
+ } else
ret = NF_ACCEPT;
}
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index 962795e..7df7b36 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c
@@ -623,7 +623,7 @@
drop:
spin_unlock_bh(&nf_h323_lock);
- net_info_ratelimited("nf_ct_h245: packet dropped\n");
+ nf_ct_helper_log(skb, ct, "cannot process H.245 message");
return NF_DROP;
}
@@ -1197,7 +1197,7 @@
drop:
spin_unlock_bh(&nf_h323_lock);
- net_info_ratelimited("nf_ct_q931: packet dropped\n");
+ nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
return NF_DROP;
}
@@ -1795,7 +1795,7 @@
drop:
spin_unlock_bh(&nf_h323_lock);
- net_info_ratelimited("nf_ct_ras: packet dropped\n");
+ nf_ct_helper_log(skb, ct, "cannot process RAS message");
return NF_DROP;
}
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 2f380f7..c08768d 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -28,6 +28,7 @@
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_extend.h>
+#include <net/netfilter/nf_log.h>
static DEFINE_MUTEX(nf_ct_helper_mutex);
struct hlist_head *nf_ct_helper_hash __read_mostly;
@@ -332,6 +333,24 @@
}
EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol);
+__printf(3, 4)
+void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct,
+ const char *fmt, ...)
+{
+ const struct nf_conn_help *help;
+ const struct nf_conntrack_helper *helper;
+
+ /* Called from the helper function, this call never fails */
+ help = nfct_help(ct);
+
+ /* rcu_read_lock()ed by nf_hook_slow */
+ helper = rcu_dereference(help->helper);
+
+ nf_log_packet(nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL,
+ "nf_ct_%s: dropping packet: %s ", helper->name, fmt);
+}
+EXPORT_SYMBOL_GPL(nf_ct_helper_log);
+
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
{
int ret = 0;
diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index 3b20aa7..70985c5 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -194,6 +194,8 @@
exp = nf_ct_expect_alloc(ct);
if (exp == NULL) {
+ nf_ct_helper_log(skb, ct,
+ "cannot alloc expectation");
ret = NF_DROP;
goto out;
}
@@ -210,8 +212,11 @@
addr_beg_p - ib_ptr,
addr_end_p - addr_beg_p,
exp);
- else if (nf_ct_expect_related(exp) != 0)
+ else if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct,
+ "cannot add expectation");
ret = NF_DROP;
+ }
nf_ct_expect_put(exp);
goto out;
}
diff --git a/net/netfilter/nf_conntrack_sane.c b/net/netfilter/nf_conntrack_sane.c
index 295429f..4a2134f 100644
--- a/net/netfilter/nf_conntrack_sane.c
+++ b/net/netfilter/nf_conntrack_sane.c
@@ -138,6 +138,7 @@
exp = nf_ct_expect_alloc(ct);
if (exp == NULL) {
+ nf_ct_helper_log(skb, ct, "cannot alloc expectation");
ret = NF_DROP;
goto out;
}
@@ -151,8 +152,10 @@
nf_ct_dump_tuple(&exp->tuple);
/* Can't expect this? Best to drop packet now. */
- if (nf_ct_expect_related(exp) != 0)
+ if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct, "cannot add expectation");
ret = NF_DROP;
+ }
nf_ct_expect_put(exp);
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 72a67bb..069229d 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1095,8 +1095,10 @@
port = simple_strtoul(*dptr + mediaoff, NULL, 10);
if (port == 0)
continue;
- if (port < 1024 || port > 65535)
+ if (port < 1024 || port > 65535) {
+ nf_ct_helper_log(skb, ct, "wrong port %u", port);
return NF_DROP;
+ }
/* The media description overrides the session description. */
maddr_len = 0;
@@ -1107,15 +1109,20 @@
memcpy(&rtp_addr, &maddr, sizeof(rtp_addr));
} else if (caddr_len)
memcpy(&rtp_addr, &caddr, sizeof(rtp_addr));
- else
+ else {
+ nf_ct_helper_log(skb, ct, "cannot parse SDP message");
return NF_DROP;
+ }
ret = set_expected_rtp_rtcp(skb, protoff, dataoff,
dptr, datalen,
&rtp_addr, htons(port), t->class,
mediaoff, medialen);
- if (ret != NF_ACCEPT)
+ if (ret != NF_ACCEPT) {
+ nf_ct_helper_log(skb, ct,
+ "cannot add expectation for voice");
return ret;
+ }
/* Update media connection address if present */
if (maddr_len && nf_nat_sdp_addr && ct->status & IPS_NAT_MASK) {
@@ -1123,8 +1130,10 @@
dptr, datalen, mediaoff,
SDP_HDR_CONNECTION, SDP_HDR_MEDIA,
&rtp_addr);
- if (ret != NF_ACCEPT)
+ if (ret != NF_ACCEPT) {
+ nf_ct_helper_log(skb, ct, "cannot mangle SDP");
return ret;
+ }
}
i++;
}
@@ -1258,9 +1267,10 @@
ret = ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
SIP_HDR_CONTACT, NULL,
&matchoff, &matchlen, &daddr, &port);
- if (ret < 0)
+ if (ret < 0) {
+ nf_ct_helper_log(skb, ct, "cannot parse contact");
return NF_DROP;
- else if (ret == 0)
+ } else if (ret == 0)
return NF_ACCEPT;
/* We don't support third-party registrations */
@@ -1273,8 +1283,10 @@
if (ct_sip_parse_numerical_param(ct, *dptr,
matchoff + matchlen, *datalen,
- "expires=", NULL, NULL, &expires) < 0)
+ "expires=", NULL, NULL, &expires) < 0) {
+ nf_ct_helper_log(skb, ct, "cannot parse expires");
return NF_DROP;
+ }
if (expires == 0) {
ret = NF_ACCEPT;
@@ -1282,8 +1294,10 @@
}
exp = nf_ct_expect_alloc(ct);
- if (!exp)
+ if (!exp) {
+ nf_ct_helper_log(skb, ct, "cannot alloc expectation");
return NF_DROP;
+ }
saddr = NULL;
if (sip_direct_signalling)
@@ -1300,9 +1314,10 @@
ret = nf_nat_sip_expect(skb, protoff, dataoff, dptr, datalen,
exp, matchoff, matchlen);
else {
- if (nf_ct_expect_related(exp) != 0)
+ if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct, "cannot add expectation");
ret = NF_DROP;
- else
+ } else
ret = NF_ACCEPT;
}
nf_ct_expect_put(exp);
@@ -1356,9 +1371,10 @@
SIP_HDR_CONTACT, &in_contact,
&matchoff, &matchlen,
&addr, &port);
- if (ret < 0)
+ if (ret < 0) {
+ nf_ct_helper_log(skb, ct, "cannot parse contact");
return NF_DROP;
- else if (ret == 0)
+ } else if (ret == 0)
break;
/* We don't support third-party registrations */
@@ -1373,8 +1389,10 @@
matchoff + matchlen,
*datalen, "expires=",
NULL, NULL, &c_expires);
- if (ret < 0)
+ if (ret < 0) {
+ nf_ct_helper_log(skb, ct, "cannot parse expires");
return NF_DROP;
+ }
if (c_expires == 0)
break;
if (refresh_signalling_expectation(ct, &addr, proto, port,
@@ -1408,15 +1426,21 @@
if (*datalen < strlen("SIP/2.0 200"))
return NF_ACCEPT;
code = simple_strtoul(*dptr + strlen("SIP/2.0 "), NULL, 10);
- if (!code)
+ if (!code) {
+ nf_ct_helper_log(skb, ct, "cannot get code");
return NF_DROP;
+ }
if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ,
- &matchoff, &matchlen) <= 0)
+ &matchoff, &matchlen) <= 0) {
+ nf_ct_helper_log(skb, ct, "cannot parse cseq");
return NF_DROP;
+ }
cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
- if (!cseq)
+ if (!cseq) {
+ nf_ct_helper_log(skb, ct, "cannot get cseq");
return NF_DROP;
+ }
matchend = matchoff + matchlen + 1;
for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
@@ -1471,11 +1495,15 @@
continue;
if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CSEQ,
- &matchoff, &matchlen) <= 0)
+ &matchoff, &matchlen) <= 0) {
+ nf_ct_helper_log(skb, ct, "cannot parse cseq");
return NF_DROP;
+ }
cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
- if (!cseq)
+ if (!cseq) {
+ nf_ct_helper_log(skb, ct, "cannot get cseq");
return NF_DROP;
+ }
return handler->request(skb, protoff, dataoff, dptr, datalen,
cseq);
@@ -1498,8 +1526,10 @@
if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
nf_nat_sip = rcu_dereference(nf_nat_sip_hook);
if (nf_nat_sip && !nf_nat_sip(skb, protoff, dataoff,
- dptr, datalen))
+ dptr, datalen)) {
+ nf_ct_helper_log(skb, ct, "cannot NAT SIP message");
ret = NF_DROP;
+ }
}
return ret;
@@ -1563,11 +1593,14 @@
end += strlen("\r\n\r\n") + clen;
msglen = origlen = end - dptr;
- if (msglen > datalen)
+ if (msglen > datalen) {
+ nf_ct_helper_log(skb, ct, "incomplete/bad SIP message");
return NF_DROP;
+ }
ret = process_sip_msg(skb, ct, protoff, dataoff,
&dptr, &msglen);
+ /* process_sip_* functions report why this packet is dropped */
if (ret != NF_ACCEPT)
break;
diff = msglen - origlen;
diff --git a/net/netfilter/nf_conntrack_tftp.c b/net/netfilter/nf_conntrack_tftp.c
index 81fc61c..e9936c8 100644
--- a/net/netfilter/nf_conntrack_tftp.c
+++ b/net/netfilter/nf_conntrack_tftp.c
@@ -60,8 +60,10 @@
nf_ct_dump_tuple(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
exp = nf_ct_expect_alloc(ct);
- if (exp == NULL)
+ if (exp == NULL) {
+ nf_ct_helper_log(skb, ct, "cannot alloc expectation");
return NF_DROP;
+ }
tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
nf_ct_l3num(ct),
@@ -74,8 +76,10 @@
nf_nat_tftp = rcu_dereference(nf_nat_tftp_hook);
if (nf_nat_tftp && ct->status & IPS_NAT_MASK)
ret = nf_nat_tftp(skb, ctinfo, exp);
- else if (nf_ct_expect_related(exp) != 0)
+ else if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct, "cannot add expectation");
ret = NF_DROP;
+ }
nf_ct_expect_put(exp);
break;
case TFTP_OPCODE_DATA:
diff --git a/net/netfilter/nf_nat_amanda.c b/net/netfilter/nf_nat_amanda.c
index 42d3378..3b67c9d 100644
--- a/net/netfilter/nf_nat_amanda.c
+++ b/net/netfilter/nf_nat_amanda.c
@@ -56,15 +56,19 @@
}
}
- if (port == 0)
+ if (port == 0) {
+ nf_ct_helper_log(skb, exp->master, "all ports in use");
return NF_DROP;
+ }
sprintf(buffer, "%u", port);
ret = nf_nat_mangle_udp_packet(skb, exp->master, ctinfo,
protoff, matchoff, matchlen,
buffer, strlen(buffer));
- if (ret != NF_ACCEPT)
+ if (ret != NF_ACCEPT) {
+ nf_ct_helper_log(skb, exp->master, "cannot mangle packet");
nf_ct_unexpect_related(exp);
+ }
return ret;
}
diff --git a/net/netfilter/nf_nat_ftp.c b/net/netfilter/nf_nat_ftp.c
index e839b97..e84a578 100644
--- a/net/netfilter/nf_nat_ftp.c
+++ b/net/netfilter/nf_nat_ftp.c
@@ -96,8 +96,10 @@
}
}
- if (port == 0)
+ if (port == 0) {
+ nf_ct_helper_log(skb, ct, "all ports in use");
return NF_DROP;
+ }
buflen = nf_nat_ftp_fmt_cmd(ct, type, buffer, sizeof(buffer),
&newaddr, port);
@@ -113,6 +115,7 @@
return NF_ACCEPT;
out:
+ nf_ct_helper_log(skb, ct, "cannot mangle packet");
nf_ct_unexpect_related(exp);
return NF_DROP;
}
diff --git a/net/netfilter/nf_nat_irc.c b/net/netfilter/nf_nat_irc.c
index 1fedee6..f02b360 100644
--- a/net/netfilter/nf_nat_irc.c
+++ b/net/netfilter/nf_nat_irc.c
@@ -56,14 +56,18 @@
}
}
- if (port == 0)
+ if (port == 0) {
+ nf_ct_helper_log(skb, exp->master, "all ports in use");
return NF_DROP;
+ }
ret = nf_nat_mangle_tcp_packet(skb, exp->master, ctinfo,
protoff, matchoff, matchlen, buffer,
strlen(buffer));
- if (ret != NF_ACCEPT)
+ if (ret != NF_ACCEPT) {
+ nf_ct_helper_log(skb, exp->master, "cannot mangle packet");
nf_ct_unexpect_related(exp);
+ }
return ret;
}
diff --git a/net/netfilter/nf_nat_sip.c b/net/netfilter/nf_nat_sip.c
index 5951146e..96ccdf7 100644
--- a/net/netfilter/nf_nat_sip.c
+++ b/net/netfilter/nf_nat_sip.c
@@ -159,8 +159,10 @@
&matchoff, &matchlen,
&addr, &port) > 0 &&
!map_addr(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, &addr, port))
+ matchoff, matchlen, &addr, port)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle SIP message");
return NF_DROP;
+ }
request = 1;
} else
request = 0;
@@ -193,8 +195,10 @@
olen = *datalen;
if (!map_addr(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, &addr, port))
+ matchoff, matchlen, &addr, port)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle Via header");
return NF_DROP;
+ }
matchend = matchoff + matchlen + *datalen - olen;
@@ -209,8 +213,10 @@
&ct->tuplehash[!dir].tuple.dst.u3,
true);
if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- poff, plen, buffer, buflen))
+ poff, plen, buffer, buflen)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle maddr");
return NF_DROP;
+ }
}
/* The received= parameter (RFC 2361) contains the address
@@ -225,6 +231,7 @@
false);
if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
poff, plen, buffer, buflen))
+ nf_ct_helper_log(skb, ct, "cannot mangle received");
return NF_DROP;
}
@@ -238,8 +245,10 @@
__be16 p = ct->tuplehash[!dir].tuple.src.u.udp.port;
buflen = sprintf(buffer, "%u", ntohs(p));
if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- poff, plen, buffer, buflen))
+ poff, plen, buffer, buflen)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle rport");
return NF_DROP;
+ }
}
}
@@ -253,27 +262,35 @@
&addr, &port) > 0) {
if (!map_addr(skb, protoff, dataoff, dptr, datalen,
matchoff, matchlen,
- &addr, port))
+ &addr, port)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle contact");
return NF_DROP;
+ }
}
if (!map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_FROM) ||
- !map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_TO))
+ !map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_TO)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle SIP from/to");
return NF_DROP;
+ }
/* Mangle destination port for Cisco phones, then fix up checksums */
if (dir == IP_CT_DIR_REPLY && ct_sip_info->forced_dport) {
struct udphdr *uh;
- if (!skb_make_writable(skb, skb->len))
+ if (!skb_make_writable(skb, skb->len)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle packet");
return NF_DROP;
+ }
uh = (void *)skb->data + protoff;
uh->dest = ct_sip_info->forced_dport;
if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, protoff,
- 0, 0, NULL, 0))
+ 0, 0, NULL, 0)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle packet");
return NF_DROP;
+ }
}
return NF_ACCEPT;
@@ -372,15 +389,19 @@
}
}
- if (port == 0)
+ if (port == 0) {
+ nf_ct_helper_log(skb, ct, "all ports in use for SIP");
return NF_DROP;
+ }
if (!nf_inet_addr_cmp(&exp->tuple.dst.u3, &exp->saved_addr) ||
exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, port);
if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
- matchoff, matchlen, buffer, buflen))
+ matchoff, matchlen, buffer, buflen)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle packet");
goto err;
+ }
}
return NF_ACCEPT;
@@ -573,14 +594,18 @@
}
}
- if (port == 0)
+ if (port == 0) {
+ nf_ct_helper_log(skb, ct, "all ports in use for SDP media");
goto err1;
+ }
/* Update media port. */
if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port &&
!nf_nat_sdp_port(skb, protoff, dataoff, dptr, datalen,
- mediaoff, medialen, port))
+ mediaoff, medialen, port)) {
+ nf_ct_helper_log(skb, ct, "cannot mangle SDP message");
goto err2;
+ }
return NF_ACCEPT;
diff --git a/net/netfilter/nf_nat_tftp.c b/net/netfilter/nf_nat_tftp.c
index ccabbda..7f67e1d 100644
--- a/net/netfilter/nf_nat_tftp.c
+++ b/net/netfilter/nf_nat_tftp.c
@@ -28,8 +28,10 @@
= ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;
exp->dir = IP_CT_DIR_REPLY;
exp->expectfn = nf_nat_follow_master;
- if (nf_ct_expect_related(exp) != 0)
+ if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, exp->master, "cannot add expectation");
return NF_DROP;
+ }
return NF_ACCEPT;
}