netfilter: nf_nat_sip: add TCP support
Add support for mangling TCP SIP packets. Signed-off-by: Patrick McHardy <kaber@trash.net>
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010c0b9f34
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48f8ac2653
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@ -104,6 +104,7 @@ extern unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
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unsigned int dataoff,
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unsigned int dataoff,
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const char **dptr,
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const char **dptr,
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unsigned int *datalen);
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unsigned int *datalen);
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extern void (*nf_nat_sip_seq_adjust_hook)(struct sk_buff *skb, s16 off);
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extern unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
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extern unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
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unsigned int dataoff,
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unsigned int dataoff,
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const char **dptr,
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const char **dptr,
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@ -1,4 +1,4 @@
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/* SIP extension for UDP NAT alteration.
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/* SIP extension for NAT alteration.
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*
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*
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* (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar>
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* (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar>
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* based on RR's ip_nat_ftp.c and other modules.
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* based on RR's ip_nat_ftp.c and other modules.
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@ -15,6 +15,7 @@
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#include <linux/ip.h>
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#include <linux/ip.h>
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#include <net/ip.h>
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#include <net/ip.h>
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#include <linux/udp.h>
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#include <linux/udp.h>
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#include <linux/tcp.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat_helper.h>
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#include <net/netfilter/nf_nat_helper.h>
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@ -36,10 +37,27 @@ static unsigned int mangle_packet(struct sk_buff *skb, unsigned int dataoff,
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{
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{
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enum ip_conntrack_info ctinfo;
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enum ip_conntrack_info ctinfo;
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struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
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struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
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struct tcphdr *th;
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unsigned int baseoff;
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if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, matchoff, matchlen,
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if (nf_ct_protonum(ct) == IPPROTO_TCP) {
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th = (struct tcphdr *)(skb->data + ip_hdrlen(skb));
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baseoff = ip_hdrlen(skb) + th->doff * 4;
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matchoff += dataoff - baseoff;
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if (!__nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
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matchoff, matchlen,
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buffer, buflen, false))
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return 0;
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} else {
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baseoff = ip_hdrlen(skb) + sizeof(struct udphdr);
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matchoff += dataoff - baseoff;
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if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
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matchoff, matchlen,
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buffer, buflen))
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buffer, buflen))
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return 0;
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return 0;
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}
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/* Reload data pointer and adjust datalen value */
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/* Reload data pointer and adjust datalen value */
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*dptr = skb->data + dataoff;
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*dptr = skb->data + dataoff;
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@ -104,6 +122,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
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struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
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struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
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enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
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enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
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unsigned int coff, matchoff, matchlen;
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unsigned int coff, matchoff, matchlen;
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enum sip_header_types hdr;
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union nf_inet_addr addr;
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union nf_inet_addr addr;
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__be16 port;
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__be16 port;
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int request, in_header;
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int request, in_header;
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@ -120,9 +139,14 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
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} else
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} else
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request = 0;
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request = 0;
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if (nf_ct_protonum(ct) == IPPROTO_TCP)
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hdr = SIP_HDR_VIA_TCP;
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else
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hdr = SIP_HDR_VIA_UDP;
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/* Translate topmost Via header and parameters */
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/* Translate topmost Via header and parameters */
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if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
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if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
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SIP_HDR_VIA_UDP, NULL, &matchoff, &matchlen,
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hdr, NULL, &matchoff, &matchlen,
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&addr, &port) > 0) {
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&addr, &port) > 0) {
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unsigned int matchend, poff, plen, buflen, n;
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unsigned int matchend, poff, plen, buflen, n;
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char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
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char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
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@ -204,9 +228,23 @@ next:
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if (!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_FROM) ||
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if (!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_FROM) ||
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!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_TO))
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!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_TO))
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return NF_DROP;
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return NF_DROP;
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return NF_ACCEPT;
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return NF_ACCEPT;
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}
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}
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static void ip_nat_sip_seq_adjust(struct sk_buff *skb, s16 off)
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{
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enum ip_conntrack_info ctinfo;
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struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
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const struct tcphdr *th;
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if (nf_ct_protonum(ct) != IPPROTO_TCP || off == 0)
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return;
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th = (struct tcphdr *)(skb->data + ip_hdrlen(skb));
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nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off);
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}
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/* Handles expected signalling connections and media streams */
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/* Handles expected signalling connections and media streams */
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static void ip_nat_sip_expected(struct nf_conn *ct,
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static void ip_nat_sip_expected(struct nf_conn *ct,
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struct nf_conntrack_expect *exp)
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struct nf_conntrack_expect *exp)
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@ -472,6 +510,7 @@ err1:
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static void __exit nf_nat_sip_fini(void)
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static void __exit nf_nat_sip_fini(void)
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{
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{
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rcu_assign_pointer(nf_nat_sip_hook, NULL);
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rcu_assign_pointer(nf_nat_sip_hook, NULL);
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rcu_assign_pointer(nf_nat_sip_seq_adjust_hook, NULL);
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rcu_assign_pointer(nf_nat_sip_expect_hook, NULL);
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rcu_assign_pointer(nf_nat_sip_expect_hook, NULL);
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rcu_assign_pointer(nf_nat_sdp_addr_hook, NULL);
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rcu_assign_pointer(nf_nat_sdp_addr_hook, NULL);
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rcu_assign_pointer(nf_nat_sdp_port_hook, NULL);
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rcu_assign_pointer(nf_nat_sdp_port_hook, NULL);
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@ -483,12 +522,14 @@ static void __exit nf_nat_sip_fini(void)
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static int __init nf_nat_sip_init(void)
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static int __init nf_nat_sip_init(void)
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{
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{
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BUG_ON(nf_nat_sip_hook != NULL);
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BUG_ON(nf_nat_sip_hook != NULL);
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BUG_ON(nf_nat_sip_seq_adjust_hook != NULL);
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BUG_ON(nf_nat_sip_expect_hook != NULL);
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BUG_ON(nf_nat_sip_expect_hook != NULL);
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BUG_ON(nf_nat_sdp_addr_hook != NULL);
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BUG_ON(nf_nat_sdp_addr_hook != NULL);
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BUG_ON(nf_nat_sdp_port_hook != NULL);
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BUG_ON(nf_nat_sdp_port_hook != NULL);
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BUG_ON(nf_nat_sdp_session_hook != NULL);
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BUG_ON(nf_nat_sdp_session_hook != NULL);
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BUG_ON(nf_nat_sdp_media_hook != NULL);
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BUG_ON(nf_nat_sdp_media_hook != NULL);
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rcu_assign_pointer(nf_nat_sip_hook, ip_nat_sip);
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rcu_assign_pointer(nf_nat_sip_hook, ip_nat_sip);
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rcu_assign_pointer(nf_nat_sip_seq_adjust_hook, ip_nat_sip_seq_adjust);
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rcu_assign_pointer(nf_nat_sip_expect_hook, ip_nat_sip_expect);
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rcu_assign_pointer(nf_nat_sip_expect_hook, ip_nat_sip_expect);
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rcu_assign_pointer(nf_nat_sdp_addr_hook, ip_nat_sdp_addr);
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rcu_assign_pointer(nf_nat_sdp_addr_hook, ip_nat_sdp_addr);
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rcu_assign_pointer(nf_nat_sdp_port_hook, ip_nat_sdp_port);
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rcu_assign_pointer(nf_nat_sdp_port_hook, ip_nat_sdp_port);
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@ -56,6 +56,9 @@ unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, unsigned int dataoff,
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unsigned int *datalen) __read_mostly;
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unsigned int *datalen) __read_mostly;
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EXPORT_SYMBOL_GPL(nf_nat_sip_hook);
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EXPORT_SYMBOL_GPL(nf_nat_sip_hook);
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void (*nf_nat_sip_seq_adjust_hook)(struct sk_buff *skb, s16 off) __read_mostly;
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EXPORT_SYMBOL_GPL(nf_nat_sip_seq_adjust_hook);
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unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
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unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
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unsigned int dataoff,
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unsigned int dataoff,
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const char **dptr,
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const char **dptr,
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@ -1360,6 +1363,7 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
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const char *dptr, *end;
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const char *dptr, *end;
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s16 diff, tdiff = 0;
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s16 diff, tdiff = 0;
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int ret;
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int ret;
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typeof(nf_nat_sip_seq_adjust_hook) nf_nat_sip_seq_adjust;
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if (ctinfo != IP_CT_ESTABLISHED &&
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if (ctinfo != IP_CT_ESTABLISHED &&
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ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY)
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ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY)
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@ -1415,6 +1419,12 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
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datalen = datalen + diff - msglen;
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datalen = datalen + diff - msglen;
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}
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}
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if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
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nf_nat_sip_seq_adjust = rcu_dereference(nf_nat_sip_seq_adjust_hook);
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if (nf_nat_sip_seq_adjust)
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nf_nat_sip_seq_adjust(skb, tdiff);
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}
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return ret;
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return ret;
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}
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}
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