[NETFILTER]: x_tables: switch hotdrop to bool
[safe/jmp/linux-2.6] / net / ipv6 / netfilter / ip6_tables.c
index c9d6b23..13c66a7 100644 (file)
@@ -7,15 +7,6 @@
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
- * 19 Jan 2002 Harald Welte <laforge@gnumonks.org>
- *     - increase module usage count as soon as we have rules inside
- *       a table
- * 06 Jun 2002 Andras Kis-Szabo <kisza@sch.bme.hu>
- *      - new extension header parser code
- * 15 Oct 2005 Harald Welte <laforge@netfilter.org>
- *     - Unification of {ip,ip6}_tables into x_tables
- *     - Removed tcp and udp code, since it's not ipv6 specific
  */
 
 #include <linux/capability.h>
@@ -70,9 +61,6 @@ do {                                                          \
 #define IP_NF_ASSERT(x)
 #endif
 
-
-#include <linux/netfilter_ipv4/listhelp.h>
-
 #if 0
 /* All the better to debug you with... */
 #define static
@@ -95,16 +83,16 @@ do {                                                                \
 #endif
 
 /* Check for an extension */
-int 
+int
 ip6t_ext_hdr(u8 nexthdr)
 {
-        return ( (nexthdr == IPPROTO_HOPOPTS)   ||
-                 (nexthdr == IPPROTO_ROUTING)   ||
-                 (nexthdr == IPPROTO_FRAGMENT)  ||
-                 (nexthdr == IPPROTO_ESP)       ||
-                 (nexthdr == IPPROTO_AH)        ||
-                 (nexthdr == IPPROTO_NONE)      ||
-                 (nexthdr == IPPROTO_DSTOPTS) );
+       return ( (nexthdr == IPPROTO_HOPOPTS)   ||
+                (nexthdr == IPPROTO_ROUTING)   ||
+                (nexthdr == IPPROTO_FRAGMENT)  ||
+                (nexthdr == IPPROTO_ESP)       ||
+                (nexthdr == IPPROTO_AH)        ||
+                (nexthdr == IPPROTO_NONE)      ||
+                (nexthdr == IPPROTO_DSTOPTS) );
 }
 
 /* Returns whether matches rule or not. */
@@ -114,18 +102,18 @@ ip6_packet_match(const struct sk_buff *skb,
                 const char *outdev,
                 const struct ip6t_ip6 *ip6info,
                 unsigned int *protoff,
-                int *fragoff)
+                int *fragoff, bool *hotdrop)
 {
        size_t i;
        unsigned long ret;
-       const struct ipv6hdr *ipv6 = skb->nh.ipv6h;
+       const struct ipv6hdr *ipv6 = ipv6_hdr(skb);
 
 #define FWINV(bool,invflg) ((bool) ^ !!(ip6info->invflags & invflg))
 
        if (FWINV(ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
-                                      &ip6info->src), IP6T_INV_SRCIP)
+                                      &ip6info->src), IP6T_INV_SRCIP)
            || FWINV(ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
-                                         &ip6info->dst), IP6T_INV_DSTIP)) {
+                                         &ip6info->dst), IP6T_INV_DSTIP)) {
                dprintf("Source or dest mismatch.\n");
 /*
                dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr,
@@ -172,13 +160,15 @@ ip6_packet_match(const struct sk_buff *skb,
                unsigned short _frag_off;
 
                protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off);
-               if (protohdr < 0)
+               if (protohdr < 0) {
+                       if (_frag_off == 0)
+                               *hotdrop = true;
                        return 0;
-
+               }
                *fragoff = _frag_off;
 
                dprintf("Packet protocol %hi ?= %s%hi.\n",
-                               protohdr, 
+                               protohdr,
                                ip6info->invflags & IP6T_INV_PROTO ? "!":"",
                                ip6info->proto);
 
@@ -198,7 +188,7 @@ ip6_packet_match(const struct sk_buff *skb,
 }
 
 /* should be ip6 safe */
-static inline int 
+static inline int
 ip6_checkentry(const struct ip6t_ip6 *ipv6)
 {
        if (ipv6->flags & ~IP6T_F_MASK) {
@@ -220,8 +210,7 @@ ip6t_error(struct sk_buff **pskb,
          const struct net_device *out,
          unsigned int hooknum,
          const struct xt_target *target,
-         const void *targinfo,
-         void *userinfo)
+         const void *targinfo)
 {
        if (net_ratelimit())
                printk("ip6_tables: error: `%s'\n", (char *)targinfo);
@@ -236,7 +225,7 @@ int do_match(struct ip6t_entry_match *m,
             const struct net_device *out,
             int offset,
             unsigned int protoff,
-            int *hotdrop)
+            bool *hotdrop)
 {
        /* Stop iteration if it doesn't match */
        if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
@@ -258,13 +247,12 @@ ip6t_do_table(struct sk_buff **pskb,
              unsigned int hook,
              const struct net_device *in,
              const struct net_device *out,
-             struct xt_table *table,
-             void *userdata)
+             struct xt_table *table)
 {
        static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
        int offset = 0;
        unsigned int protoff = 0;
-       int hotdrop = 0;
+       bool hotdrop = false;
        /* Initializing verdict to NF_DROP keeps gcc happy. */
        unsigned int verdict = NF_DROP;
        const char *indev, *outdev;
@@ -295,7 +283,7 @@ ip6t_do_table(struct sk_buff **pskb,
                IP_NF_ASSERT(e);
                IP_NF_ASSERT(back);
                if (ip6_packet_match(*pskb, indev, outdev, &e->ipv6,
-                       &protoff, &offset)) {
+                       &protoff, &offset, &hotdrop)) {
                        struct ip6t_entry_target *t;
 
                        if (IP6T_MATCH_ITERATE(e, do_match,
@@ -304,7 +292,7 @@ ip6t_do_table(struct sk_buff **pskb,
                                goto no_match;
 
                        ADD_COUNTER(e->counters,
-                                   ntohs((*pskb)->nh.ipv6h->payload_len)
+                                   ntohs(ipv6_hdr(*pskb)->payload_len)
                                    + IPV6_HDR_LEN,
                                    1);
 
@@ -340,7 +328,7 @@ ip6t_do_table(struct sk_buff **pskb,
                                e = get_entry(table_base, v);
                        } else {
                                /* Targets which reenter must return
-                                   abs. verdicts */
+                                  abs. verdicts */
 #ifdef CONFIG_NETFILTER_DEBUG
                                ((struct ip6t_entry *)table_base)->comefrom
                                        = 0xeeeeeeec;
@@ -349,8 +337,7 @@ ip6t_do_table(struct sk_buff **pskb,
                                                                     in, out,
                                                                     hook,
                                                                     t->u.kernel.target,
-                                                                    t->data,
-                                                                    userdata);
+                                                                    t->data);
 
 #ifdef CONFIG_NETFILTER_DEBUG
                                if (((struct ip6t_entry *)table_base)->comefrom
@@ -417,6 +404,7 @@ mark_source_chains(struct xt_table_info *newinfo,
                unsigned int pos = newinfo->hook_entry[hook];
                struct ip6t_entry *e
                        = (struct ip6t_entry *)(entry0 + pos);
+               int visited = e->comefrom & (1 << hook);
 
                if (!(valid_hooks & (1 << hook)))
                        continue;
@@ -437,13 +425,20 @@ mark_source_chains(struct xt_table_info *newinfo,
                                |= ((1 << hook) | (1 << NF_IP6_NUMHOOKS));
 
                        /* Unconditional return/END. */
-                       if (e->target_offset == sizeof(struct ip6t_entry)
+                       if ((e->target_offset == sizeof(struct ip6t_entry)
                            && (strcmp(t->target.u.user.name,
                                       IP6T_STANDARD_TARGET) == 0)
                            && t->verdict < 0
-                           && unconditional(&e->ipv6)) {
+                           && unconditional(&e->ipv6)) || visited) {
                                unsigned int oldpos, size;
 
+                               if (t->verdict < -NF_MAX_VERDICT - 1) {
+                                       duprintf("mark_source_chains: bad "
+                                               "negative verdict (%i)\n",
+                                                               t->verdict);
+                                       return 0;
+                               }
+
                                /* Return: backtrack through the last
                                   big jump. */
                                do {
@@ -481,6 +476,13 @@ mark_source_chains(struct xt_table_info *newinfo,
                                if (strcmp(t->target.u.user.name,
                                           IP6T_STANDARD_TARGET) == 0
                                    && newpos >= 0) {
+                                       if (newpos > newinfo->size -
+                                               sizeof(struct ip6t_entry)) {
+                                               duprintf("mark_source_chains: "
+                                                       "bad verdict (%i)\n",
+                                                               newpos);
+                                               return 0;
+                                       }
                                        /* This a jump; chase it. */
                                        duprintf("Jump rule %u -> %u\n",
                                                 pos, newpos);
@@ -507,48 +509,26 @@ cleanup_match(struct ip6t_entry_match *m, unsigned int *i)
                return 1;
 
        if (m->u.kernel.match->destroy)
-               m->u.kernel.match->destroy(m->u.kernel.match, m->data,
-                                          m->u.match_size - sizeof(*m));
+               m->u.kernel.match->destroy(m->u.kernel.match, m->data);
        module_put(m->u.kernel.match->me);
        return 0;
 }
 
 static inline int
-standard_check(const struct ip6t_entry_target *t,
-              unsigned int max_offset)
-{
-       struct ip6t_standard_target *targ = (void *)t;
-
-       /* Check standard info. */
-       if (targ->verdict >= 0
-           && targ->verdict > max_offset - sizeof(struct ip6t_entry)) {
-               duprintf("ip6t_standard_check: bad verdict (%i)\n",
-                        targ->verdict);
-               return 0;
-       }
-       if (targ->verdict < -NF_MAX_VERDICT - 1) {
-               duprintf("ip6t_standard_check: bad negative verdict (%i)\n",
-                        targ->verdict);
-               return 0;
-       }
-       return 1;
-}
-
-static inline int
 check_match(struct ip6t_entry_match *m,
            const char *name,
            const struct ip6t_ip6 *ipv6,
            unsigned int hookmask,
            unsigned int *i)
 {
-       struct ip6t_match *match;
+       struct xt_match *match;
        int ret;
 
        match = try_then_request_module(xt_find_match(AF_INET6, m->u.user.name,
-                                       m->u.user.revision),
+                                       m->u.user.revision),
                                        "ip6t_%s", m->u.user.name);
        if (IS_ERR(match) || !match) {
-               duprintf("check_match: `%s' not found\n", m->u.user.name);
+               duprintf("check_match: `%s' not found\n", m->u.user.name);
                return match ? PTR_ERR(match) : -ENOENT;
        }
        m->u.kernel.match = match;
@@ -561,7 +541,6 @@ check_match(struct ip6t_entry_match *m,
 
        if (m->u.kernel.match->checkentry
            && !m->u.kernel.match->checkentry(name, ipv6, match,  m->data,
-                                             m->u.match_size - sizeof(*m),
                                              hookmask)) {
                duprintf("ip_tables: check failed for `%s'.\n",
                         m->u.kernel.match->name);
@@ -576,14 +555,14 @@ err:
        return ret;
 }
 
-static struct ip6t_target ip6t_standard_target;
+static struct xt_target ip6t_standard_target;
 
 static inline int
 check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
            unsigned int *i)
 {
        struct ip6t_entry_target *t;
-       struct ip6t_target *target;
+       struct xt_target *target;
        int ret;
        unsigned int j;
 
@@ -592,12 +571,19 @@ check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
                return -EINVAL;
        }
 
+       if (e->target_offset + sizeof(struct ip6t_entry_target) >
+                                                               e->next_offset)
+               return -EINVAL;
+
        j = 0;
        ret = IP6T_MATCH_ITERATE(e, check_match, name, &e->ipv6, e->comefrom, &j);
        if (ret != 0)
                goto cleanup_matches;
 
        t = ip6t_get_target(e);
+       ret = -EINVAL;
+       if (e->target_offset + t->u.target_size > e->next_offset)
+                       goto cleanup_matches;
        target = try_then_request_module(xt_find_target(AF_INET6,
                                                        t->u.user.name,
                                                        t->u.user.revision),
@@ -615,15 +601,8 @@ check_entry(struct ip6t_entry *e, const char *name, unsigned int size,
        if (ret)
                goto err;
 
-       if (t->u.kernel.target == &ip6t_standard_target) {
-               if (!standard_check(t, size)) {
-                       ret = -EINVAL;
-                       goto cleanup_matches;
-               }
-       } else if (t->u.kernel.target->checkentry
+       if (t->u.kernel.target->checkentry
                   && !t->u.kernel.target->checkentry(name, e, target, t->data,
-                                                     t->u.target_size
-                                                     - sizeof(*t),
                                                      e->comefrom)) {
                duprintf("ip_tables: check failed for `%s'.\n",
                         t->u.kernel.target->name);
@@ -673,7 +652,7 @@ check_entry_size_and_hooks(struct ip6t_entry *e,
        }
 
        /* FIXME: underflows must be unconditional, standard verdicts
-           < 0 (not IP6T_RETURN). --RR */
+          < 0 (not IP6T_RETURN). --RR */
 
        /* Clear counters and comefrom */
        e->counters = ((struct xt_counters) { 0, 0 });
@@ -695,8 +674,7 @@ cleanup_entry(struct ip6t_entry *e, unsigned int *i)
        IP6T_MATCH_ITERATE(e, cleanup_match, NULL);
        t = ip6t_get_target(e);
        if (t->u.kernel.target->destroy)
-               t->u.kernel.target->destroy(t->u.kernel.target, t->data,
-                                           t->u.target_size - sizeof(*t));
+               t->u.kernel.target->destroy(t->u.kernel.target, t->data);
        module_put(t->u.kernel.target->me);
        return 0;
 }
@@ -770,7 +748,7 @@ translate_table(const char *name,
 
        if (ret != 0) {
                IP6T_ENTRY_ITERATE(entry0, newinfo->size,
-                                 cleanup_entry, &i);
+                                  cleanup_entry, &i);
                return ret;
        }
 
@@ -780,7 +758,7 @@ translate_table(const char *name,
                        memcpy(newinfo->entries[i], entry0, newinfo->size);
        }
 
-       return ret;
+       return 0;
 }
 
 /* Gets counters. */
@@ -1016,8 +994,8 @@ do_replace(void __user *user, unsigned int len)
        /* Update module usage count based on number of rules */
        duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
                oldinfo->number, oldinfo->initial_entries, newinfo->number);
-       if ((oldinfo->number > oldinfo->initial_entries) || 
-           (newinfo->number <= oldinfo->initial_entries)) 
+       if ((oldinfo->number > oldinfo->initial_entries) ||
+           (newinfo->number <= oldinfo->initial_entries))
                module_put(t->me);
        if ((oldinfo->number > oldinfo->initial_entries) &&
            (newinfo->number <= oldinfo->initial_entries))
@@ -1321,7 +1299,7 @@ icmp6_match(const struct sk_buff *skb,
           const void *matchinfo,
           int offset,
           unsigned int protoff,
-          int *hotdrop)
+          bool *hotdrop)
 {
        struct icmp6hdr _icmp, *ic;
        const struct ip6t_icmp *icmpinfo = matchinfo;
@@ -1335,7 +1313,7 @@ icmp6_match(const struct sk_buff *skb,
                /* We've been asked to examine this packet, and we
                   can't.  Hence, no choice but to drop. */
                duprintf("Dropping evil ICMP tinygram.\n");
-               *hotdrop = 1;
+               *hotdrop = true;
                return 0;
        }
 
@@ -1352,7 +1330,6 @@ icmp6_checkentry(const char *tablename,
           const void *entry,
           const struct xt_match *match,
           void *matchinfo,
-          unsigned int matchsize,
           unsigned int hook_mask)
 {
        const struct ip6t_icmp *icmpinfo = matchinfo;
@@ -1362,13 +1339,13 @@ icmp6_checkentry(const char *tablename,
 }
 
 /* The built-in targets: standard (NULL) and error. */
-static struct ip6t_target ip6t_standard_target = {
+static struct xt_target ip6t_standard_target = {
        .name           = IP6T_STANDARD_TARGET,
        .targetsize     = sizeof(int),
        .family         = AF_INET6,
 };
 
-static struct ip6t_target ip6t_error_target = {
+static struct xt_target ip6t_error_target = {
        .name           = IP6T_ERROR_TARGET,
        .target         = ip6t_error,
        .targetsize     = IP6T_FUNCTION_MAXNAMELEN,
@@ -1385,7 +1362,7 @@ static struct nf_sockopt_ops ip6t_sockopts = {
        .get            = do_ip6t_get_ctl,
 };
 
-static struct ip6t_match icmp6_matchstruct = {
+static struct xt_match icmp6_matchstruct = {
        .name           = "icmp6",
        .match          = &icmp6_match,
        .matchsize      = sizeof(struct ip6t_icmp),
@@ -1450,6 +1427,9 @@ static void __exit ip6_tables_fini(void)
  * If target header is found, its offset is set in *offset and return protocol
  * number. Otherwise, return -1.
  *
+ * If the first fragment doesn't contain the final protocol header or
+ * NEXTHDR_NONE it is considered invalid.
+ *
  * Note that non-1st fragment is special case that "the protocol number
  * of last header" is "next header" field in Fragment header. In this case,
  * *offset is meaningless and fragment offset is stored in *fragoff if fragoff
@@ -1459,8 +1439,8 @@ static void __exit ip6_tables_fini(void)
 int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
                  int target, unsigned short *fragoff)
 {
-       unsigned int start = (u8*)(skb->nh.ipv6h + 1) - skb->data;
-       u8 nexthdr = skb->nh.ipv6h->nexthdr;
+       unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
+       u8 nexthdr = ipv6_hdr(skb)->nexthdr;
        unsigned int len = skb->len - start;
 
        if (fragoff)
@@ -1473,38 +1453,39 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
                if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
                        if (target < 0)
                                break;
-                       return -1;
+                       return -ENOENT;
                }
 
                hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
                if (hp == NULL)
-                       return -1;
+                       return -EBADMSG;
                if (nexthdr == NEXTHDR_FRAGMENT) {
-                       unsigned short _frag_off, *fp;
+                       unsigned short _frag_off;
+                       __be16 *fp;
                        fp = skb_header_pointer(skb,
                                                start+offsetof(struct frag_hdr,
                                                               frag_off),
                                                sizeof(_frag_off),
                                                &_frag_off);
                        if (fp == NULL)
-                               return -1;
+                               return -EBADMSG;
 
                        _frag_off = ntohs(*fp) & ~0x7;
                        if (_frag_off) {
                                if (target < 0 &&
                                    ((!ipv6_ext_hdr(hp->nexthdr)) ||
-                                    nexthdr == NEXTHDR_NONE)) {
+                                    hp->nexthdr == NEXTHDR_NONE)) {
                                        if (fragoff)
                                                *fragoff = _frag_off;
                                        return hp->nexthdr;
                                }
-                               return -1;
+                               return -ENOENT;
                        }
                        hdrlen = 8;
                } else if (nexthdr == NEXTHDR_AUTH)
-                       hdrlen = (hp->hdrlen + 2) << 2; 
+                       hdrlen = (hp->hdrlen + 2) << 2;
                else
-                       hdrlen = ipv6_optlen(hp); 
+                       hdrlen = ipv6_optlen(hp);
 
                nexthdr = hp->nexthdr;
                len -= hdrlen;