vserver 1.9.3

[linux-2.6.git] / net / ipv4 / netfilter / ip_tables.c

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index f24f17b..8da90bd 100644 (file)
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -61,6 +61,8 @@ do {                                                          \
 #endif
 #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
 
+static DECLARE_MUTEX(ipt_mutex);
+
 /* Must have mutex */
 #define ASSERT_READ_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0)
 #define ASSERT_WRITE_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0)
@@ -1458,21 +1460,27 @@ tcp_find_option(u_int8_t option,
                int *hotdrop)
 {
        /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
-       u_int8_t opt[60 - sizeof(struct tcphdr)];
+       u_int8_t _opt[60 - sizeof(struct tcphdr)], *op;
        unsigned int i;
 
        duprintf("tcp_match: finding option\n");
+
+       if (!optlen)
+               return invert;
+
        /* If we don't have the whole header, drop packet. */
-       if (skb_copy_bits(skb, skb->nh.iph->ihl*4 + sizeof(struct tcphdr),
-                         opt, optlen) < 0) {
+       op = skb_header_pointer(skb,
+                               skb->nh.iph->ihl*4 + sizeof(struct tcphdr),
+                               optlen, _opt);
+       if (op == NULL) {
                *hotdrop = 1;
                return 0;
        }
 
        for (i = 0; i < optlen; ) {
-               if (opt[i] == option) return !invert;
-               if (opt[i] < 2) i++;
-               else i += opt[i+1]?:1;
+               if (op[i] == option) return !invert;
+               if (op[i] < 2) i++;
+               else i += op[i+1]?:1;
        }
 
        return invert;
@@ -1486,7 +1494,7 @@ tcp_match(const struct sk_buff *skb,
          int offset,
          int *hotdrop)
 {
-       struct tcphdr tcph;
+       struct tcphdr _tcph, *th;
        const struct ipt_tcp *tcpinfo = matchinfo;
 
        if (offset) {
@@ -1506,7 +1514,9 @@ tcp_match(const struct sk_buff *skb,
 
 #define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg))
 
-       if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &tcph, sizeof(tcph)) < 0) {
+       th = skb_header_pointer(skb, skb->nh.iph->ihl*4,
+                               sizeof(_tcph), &_tcph);
+       if (th == NULL) {
                /* We've been asked to examine this packet, and we
                   can't.  Hence, no choice but to drop. */
                duprintf("Dropping evil TCP offset=0 tinygram.\n");
@@ -1515,23 +1525,24 @@ tcp_match(const struct sk_buff *skb,
        }
 
        if (!port_match(tcpinfo->spts[0], tcpinfo->spts[1],
-                       ntohs(tcph.source),
+                       ntohs(th->source),
                        !!(tcpinfo->invflags & IPT_TCP_INV_SRCPT)))
                return 0;
        if (!port_match(tcpinfo->dpts[0], tcpinfo->dpts[1],
-                       ntohs(tcph.dest),
+                       ntohs(th->dest),
                        !!(tcpinfo->invflags & IPT_TCP_INV_DSTPT)))
                return 0;
-       if (!FWINVTCP((((unsigned char *)&tcph)[13] & tcpinfo->flg_mask)
+       if (!FWINVTCP((((unsigned char *)th)[13] & tcpinfo->flg_mask)
                      == tcpinfo->flg_cmp,
                      IPT_TCP_INV_FLAGS))
                return 0;
        if (tcpinfo->option) {
-               if (tcph.doff * 4 < sizeof(tcph)) {
+               if (th->doff * 4 < sizeof(_tcph)) {
                        *hotdrop = 1;
                        return 0;
                }
-               if (!tcp_find_option(tcpinfo->option, skb, tcph.doff*4 - sizeof(tcph),
+               if (!tcp_find_option(tcpinfo->option, skb,
+                                    th->doff*4 - sizeof(_tcph),
                                     tcpinfo->invflags & IPT_TCP_INV_OPTION,
                                     hotdrop))
                        return 0;
@@ -1564,14 +1575,16 @@ udp_match(const struct sk_buff *skb,
          int offset,
          int *hotdrop)
 {
-       struct udphdr udph;
+       struct udphdr _udph, *uh;
        const struct ipt_udp *udpinfo = matchinfo;
 
        /* Must not be a fragment. */
        if (offset)
                return 0;
 
-       if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &udph, sizeof(udph)) < 0) {
+       uh = skb_header_pointer(skb, skb->nh.iph->ihl*4,
+                               sizeof(_udph), &_udph);
+       if (uh == NULL) {
                /* We've been asked to examine this packet, and we
                   can't.  Hence, no choice but to drop. */
                duprintf("Dropping evil UDP tinygram.\n");
@@ -1580,10 +1593,10 @@ udp_match(const struct sk_buff *skb,
        }
 
        return port_match(udpinfo->spts[0], udpinfo->spts[1],
-                         ntohs(udph.source),
+                         ntohs(uh->source),
                          !!(udpinfo->invflags & IPT_UDP_INV_SRCPT))
                && port_match(udpinfo->dpts[0], udpinfo->dpts[1],
-                             ntohs(udph.dest),
+                             ntohs(uh->dest),
                              !!(udpinfo->invflags & IPT_UDP_INV_DSTPT));
 }
 
@@ -1635,16 +1648,19 @@ icmp_match(const struct sk_buff *skb,
           int offset,
           int *hotdrop)
 {
-       struct icmphdr icmph;
+       struct icmphdr _icmph, *ic;
        const struct ipt_icmp *icmpinfo = matchinfo;
 
        /* Must not be a fragment. */
        if (offset)
                return 0;
 
-       if (skb_copy_bits(skb, skb->nh.iph->ihl*4, &icmph, sizeof(icmph)) < 0){
+       ic = skb_header_pointer(skb, skb->nh.iph->ihl*4,
+                               sizeof(_icmph), &_icmph);
+       if (ic == NULL) {
                /* We've been asked to examine this packet, and we
-                  can't.  Hence, no choice but to drop. */
+                * can't.  Hence, no choice but to drop.
+                */
                duprintf("Dropping evil ICMP tinygram.\n");
                *hotdrop = 1;
                return 0;
@@ -1653,7 +1669,7 @@ icmp_match(const struct sk_buff *skb,
        return icmp_type_code_match(icmpinfo->type,
                                    icmpinfo->code[0],
                                    icmpinfo->code[1],
-                                   icmph.type, icmph.code,
+                                   ic->type, ic->code,
                                    !!(icmpinfo->invflags&IPT_ICMP_INV));
 }