diff options
Diffstat (limited to 'net/bridge/netfilter/ebtables.c')
-rw-r--r-- | net/bridge/netfilter/ebtables.c | 1159 |
1 files changed, 1040 insertions, 119 deletions
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 4370e968048..dfb58056a89 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -33,11 +33,6 @@ #define BUGPRINT(format, args...) printk("kernel msg: ebtables bug: please "\ "report to author: "format, ## args) /* #define BUGPRINT(format, args...) */ -#define MEMPRINT(format, args...) printk("kernel msg: ebtables "\ - ": out of memory: "format, ## args) -/* #define MEMPRINT(format, args...) */ - - /* * Each cpu has its own set of counters, so there is no need for write_lock in @@ -56,11 +51,37 @@ static DEFINE_MUTEX(ebt_mutex); +#ifdef CONFIG_COMPAT +static void ebt_standard_compat_from_user(void *dst, const void *src) +{ + int v = *(compat_int_t *)src; + + if (v >= 0) + v += xt_compat_calc_jump(NFPROTO_BRIDGE, v); + memcpy(dst, &v, sizeof(v)); +} + +static int ebt_standard_compat_to_user(void __user *dst, const void *src) +{ + compat_int_t cv = *(int *)src; + + if (cv >= 0) + cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv); + return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; +} +#endif + + static struct xt_target ebt_standard_target = { .name = "standard", .revision = 0, .family = NFPROTO_BRIDGE, .targetsize = sizeof(int), +#ifdef CONFIG_COMPAT + .compatsize = sizeof(compat_int_t), + .compat_from_user = ebt_standard_compat_from_user, + .compat_to_user = ebt_standard_compat_to_user, +#endif }; static inline int @@ -959,91 +980,45 @@ static void get_counters(const struct ebt_counter *oldcounters, } } -/* replace the table */ -static int do_replace(struct net *net, const void __user *user, - unsigned int len) +static int do_replace_finish(struct net *net, struct ebt_replace *repl, + struct ebt_table_info *newinfo) { - int ret, i, countersize; - struct ebt_table_info *newinfo; - struct ebt_replace tmp; - struct ebt_table *t; + int ret, i; struct ebt_counter *counterstmp = NULL; /* used to be able to unlock earlier */ struct ebt_table_info *table; - - if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) - return -EFAULT; - - if (len != sizeof(tmp) + tmp.entries_size) { - BUGPRINT("Wrong len argument\n"); - return -EINVAL; - } - - if (tmp.entries_size == 0) { - BUGPRINT("Entries_size never zero\n"); - return -EINVAL; - } - /* overflow check */ - if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / NR_CPUS - - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) - return -ENOMEM; - if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) - return -ENOMEM; - - countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; - newinfo = vmalloc(sizeof(*newinfo) + countersize); - if (!newinfo) - return -ENOMEM; - - if (countersize) - memset(newinfo->counters, 0, countersize); - - newinfo->entries = vmalloc(tmp.entries_size); - if (!newinfo->entries) { - ret = -ENOMEM; - goto free_newinfo; - } - if (copy_from_user( - newinfo->entries, tmp.entries, tmp.entries_size) != 0) { - BUGPRINT("Couldn't copy entries from userspace\n"); - ret = -EFAULT; - goto free_entries; - } + struct ebt_table *t; /* the user wants counters back the check on the size is done later, when we have the lock */ - if (tmp.num_counters) { - counterstmp = vmalloc(tmp.num_counters * sizeof(*counterstmp)); - if (!counterstmp) { - ret = -ENOMEM; - goto free_entries; - } + if (repl->num_counters) { + unsigned long size = repl->num_counters * sizeof(*counterstmp); + counterstmp = vmalloc(size); + if (!counterstmp) + return -ENOMEM; } - else - counterstmp = NULL; - /* this can get initialized by translate_table() */ newinfo->chainstack = NULL; - ret = ebt_verify_pointers(&tmp, newinfo); + ret = ebt_verify_pointers(repl, newinfo); if (ret != 0) goto free_counterstmp; - ret = translate_table(net, tmp.name, newinfo); + ret = translate_table(net, repl->name, newinfo); if (ret != 0) goto free_counterstmp; - t = find_table_lock(net, tmp.name, &ret, &ebt_mutex); + t = find_table_lock(net, repl->name, &ret, &ebt_mutex); if (!t) { ret = -ENOENT; goto free_iterate; } /* the table doesn't like it */ - if (t->check && (ret = t->check(newinfo, tmp.valid_hooks))) + if (t->check && (ret = t->check(newinfo, repl->valid_hooks))) goto free_unlock; - if (tmp.num_counters && tmp.num_counters != t->private->nentries) { + if (repl->num_counters && repl->num_counters != t->private->nentries) { BUGPRINT("Wrong nr. of counters requested\n"); ret = -EINVAL; goto free_unlock; @@ -1059,7 +1034,7 @@ static int do_replace(struct net *net, const void __user *user, module_put(t->me); /* we need an atomic snapshot of the counters */ write_lock_bh(&t->lock); - if (tmp.num_counters) + if (repl->num_counters) get_counters(t->private->counters, counterstmp, t->private->nentries); @@ -1070,10 +1045,9 @@ static int do_replace(struct net *net, const void __user *user, allocation. Only reason why this is done is because this way the lock is held only once, while this doesn't bring the kernel into a dangerous state. */ - if (tmp.num_counters && - copy_to_user(tmp.counters, counterstmp, - tmp.num_counters * sizeof(struct ebt_counter))) { - BUGPRINT("Couldn't copy counters to userspace\n"); + if (repl->num_counters && + copy_to_user(repl->counters, counterstmp, + repl->num_counters * sizeof(struct ebt_counter))) { ret = -EFAULT; } else @@ -1107,6 +1081,59 @@ free_counterstmp: vfree(newinfo->chainstack[i]); vfree(newinfo->chainstack); } + return ret; +} + +/* replace the table */ +static int do_replace(struct net *net, const void __user *user, + unsigned int len) +{ + int ret, countersize; + struct ebt_table_info *newinfo; + struct ebt_replace tmp; + + if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) + return -EFAULT; + + if (len != sizeof(tmp) + tmp.entries_size) { + BUGPRINT("Wrong len argument\n"); + return -EINVAL; + } + + if (tmp.entries_size == 0) { + BUGPRINT("Entries_size never zero\n"); + return -EINVAL; + } + /* overflow check */ + if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / + NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) + return -ENOMEM; + if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) + return -ENOMEM; + + countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; + newinfo = vmalloc(sizeof(*newinfo) + countersize); + if (!newinfo) + return -ENOMEM; + + if (countersize) + memset(newinfo->counters, 0, countersize); + + newinfo->entries = vmalloc(tmp.entries_size); + if (!newinfo->entries) { + ret = -ENOMEM; + goto free_newinfo; + } + if (copy_from_user( + newinfo->entries, tmp.entries, tmp.entries_size) != 0) { + BUGPRINT("Couldn't copy entries from userspace\n"); + ret = -EFAULT; + goto free_entries; + } + + ret = do_replace_finish(net, &tmp, newinfo); + if (ret == 0) + return ret; free_entries: vfree(newinfo->entries); free_newinfo: @@ -1241,40 +1268,33 @@ void ebt_unregister_table(struct net *net, struct ebt_table *table) } /* userspace just supplied us with counters */ -static int update_counters(struct net *net, const void __user *user, - unsigned int len) +static int do_update_counters(struct net *net, const char *name, + struct ebt_counter __user *counters, + unsigned int num_counters, + const void __user *user, unsigned int len) { int i, ret; struct ebt_counter *tmp; - struct ebt_replace hlp; struct ebt_table *t; - if (copy_from_user(&hlp, user, sizeof(hlp))) - return -EFAULT; - - if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) - return -EINVAL; - if (hlp.num_counters == 0) + if (num_counters == 0) return -EINVAL; - if (!(tmp = vmalloc(hlp.num_counters * sizeof(*tmp)))) { - MEMPRINT("Update_counters && nomemory\n"); + tmp = vmalloc(num_counters * sizeof(*tmp)); + if (!tmp) return -ENOMEM; - } - t = find_table_lock(net, hlp.name, &ret, &ebt_mutex); + t = find_table_lock(net, name, &ret, &ebt_mutex); if (!t) goto free_tmp; - if (hlp.num_counters != t->private->nentries) { + if (num_counters != t->private->nentries) { BUGPRINT("Wrong nr of counters\n"); ret = -EINVAL; goto unlock_mutex; } - if ( copy_from_user(tmp, hlp.counters, - hlp.num_counters * sizeof(struct ebt_counter)) ) { - BUGPRINT("Updata_counters && !cfu\n"); + if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) { ret = -EFAULT; goto unlock_mutex; } @@ -1283,7 +1303,7 @@ static int update_counters(struct net *net, const void __user *user, write_lock_bh(&t->lock); /* we add to the counters of the first cpu */ - for (i = 0; i < hlp.num_counters; i++) { + for (i = 0; i < num_counters; i++) { t->private->counters[i].pcnt += tmp[i].pcnt; t->private->counters[i].bcnt += tmp[i].bcnt; } @@ -1297,6 +1317,21 @@ free_tmp: return ret; } +static int update_counters(struct net *net, const void __user *user, + unsigned int len) +{ + struct ebt_replace hlp; + + if (copy_from_user(&hlp, user, sizeof(hlp))) + return -EFAULT; + + if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) + return -EINVAL; + + return do_update_counters(net, hlp.name, hlp.counters, + hlp.num_counters, user, len); +} + static inline int ebt_make_matchname(const struct ebt_entry_match *m, const char *base, char __user *ubase) { @@ -1339,14 +1374,46 @@ ebt_make_names(struct ebt_entry *e, const char *base, char __user *ubase) return 0; } +static int copy_counters_to_user(struct ebt_table *t, + const struct ebt_counter *oldcounters, + void __user *user, unsigned int num_counters, + unsigned int nentries) +{ + struct ebt_counter *counterstmp; + int ret = 0; + + /* userspace might not need the counters */ + if (num_counters == 0) + return 0; + + if (num_counters != nentries) { + BUGPRINT("Num_counters wrong\n"); + return -EINVAL; + } + + counterstmp = vmalloc(nentries * sizeof(*counterstmp)); + if (!counterstmp) + return -ENOMEM; + + write_lock_bh(&t->lock); + get_counters(oldcounters, counterstmp, nentries); + write_unlock_bh(&t->lock); + + if (copy_to_user(user, counterstmp, + nentries * sizeof(struct ebt_counter))) + ret = -EFAULT; + vfree(counterstmp); + return ret; +} + /* called with ebt_mutex locked */ static int copy_everything_to_user(struct ebt_table *t, void __user *user, const int *len, int cmd) { struct ebt_replace tmp; - struct ebt_counter *counterstmp; const struct ebt_counter *oldcounters; unsigned int entries_size, nentries; + int ret; char *entries; if (cmd == EBT_SO_GET_ENTRIES) { @@ -1361,16 +1428,12 @@ static int copy_everything_to_user(struct ebt_table *t, void __user *user, oldcounters = t->table->counters; } - if (copy_from_user(&tmp, user, sizeof(tmp))) { - BUGPRINT("Cfu didn't work\n"); + if (copy_from_user(&tmp, user, sizeof(tmp))) return -EFAULT; - } if (*len != sizeof(struct ebt_replace) + entries_size + - (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0)) { - BUGPRINT("Wrong size\n"); + (tmp.num_counters? nentries * sizeof(struct ebt_counter): 0)) return -EINVAL; - } if (tmp.nentries != nentries) { BUGPRINT("Nentries wrong\n"); @@ -1382,29 +1445,10 @@ static int copy_everything_to_user(struct ebt_table *t, void __user *user, return -EINVAL; } - /* userspace might not need the counters */ - if (tmp.num_counters) { - if (tmp.num_counters != nentries) { - BUGPRINT("Num_counters wrong\n"); - return -EINVAL; - } - counterstmp = vmalloc(nentries * sizeof(*counterstmp)); - if (!counterstmp) { - MEMPRINT("Couldn't copy counters, out of memory\n"); - return -ENOMEM; - } - write_lock_bh(&t->lock); - get_counters(oldcounters, counterstmp, nentries); - write_unlock_bh(&t->lock); - - if (copy_to_user(tmp.counters, counterstmp, - nentries * sizeof(struct ebt_counter))) { - BUGPRINT("Couldn't copy counters to userspace\n"); - vfree(counterstmp); - return -EFAULT; - } - vfree(counterstmp); - } + ret = copy_counters_to_user(t, oldcounters, tmp.counters, + tmp.num_counters, nentries); + if (ret) + return ret; if (copy_to_user(tmp.entries, entries, entries_size)) { BUGPRINT("Couldn't copy entries to userspace\n"); @@ -1432,7 +1476,7 @@ static int do_ebt_set_ctl(struct sock *sk, break; default: ret = -EINVAL; - } + } return ret; } @@ -1492,15 +1536,892 @@ static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) return ret; } +#ifdef CONFIG_COMPAT +/* 32 bit-userspace compatibility definitions. */ +struct compat_ebt_replace { + char name[EBT_TABLE_MAXNAMELEN]; + compat_uint_t valid_hooks; + compat_uint_t nentries; + compat_uint_t entries_size; + /* start of the chains */ + compat_uptr_t hook_entry[NF_BR_NUMHOOKS]; + /* nr of counters userspace expects back */ + compat_uint_t num_counters; + /* where the kernel will put the old counters. */ + compat_uptr_t counters; + compat_uptr_t entries; +}; + +/* struct ebt_entry_match, _target and _watcher have same layout */ +struct compat_ebt_entry_mwt { + union { + char name[EBT_FUNCTION_MAXNAMELEN]; + compat_uptr_t ptr; + } u; + compat_uint_t match_size; + compat_uint_t data[0]; +}; + +/* account for possible padding between match_size and ->data */ +static int ebt_compat_entry_padsize(void) +{ + BUILD_BUG_ON(XT_ALIGN(sizeof(struct ebt_entry_match)) < + COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt))); + return (int) XT_ALIGN(sizeof(struct ebt_entry_match)) - + COMPAT_XT_ALIGN(sizeof(struct compat_ebt_entry_mwt)); +} + +static int ebt_compat_match_offset(const struct xt_match *match, + unsigned int userlen) +{ + /* + * ebt_among needs special handling. The kernel .matchsize is + * set to -1 at registration time; at runtime an EBT_ALIGN()ed + * value is expected. + * Example: userspace sends 4500, ebt_among.c wants 4504. + */ + if (unlikely(match->matchsize == -1)) + return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen); + return xt_compat_match_offset(match); +} + +static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr, + unsigned int *size) +{ + const struct xt_match *match = m->u.match; + struct compat_ebt_entry_mwt __user *cm = *dstptr; + int off = ebt_compat_match_offset(match, m->match_size); + compat_uint_t msize = m->match_size - off; + + BUG_ON(off >= m->match_size); + + if (copy_to_user(cm->u.name, match->name, + strlen(match->name) + 1) || put_user(msize, &cm->match_size)) + return -EFAULT; + + if (match->compat_to_user) { + if (match->compat_to_user(cm->data, m->data)) + return -EFAULT; + } else if (copy_to_user(cm->data, m->data, msize)) + return -EFAULT; + + *size -= ebt_compat_entry_padsize() + off; + *dstptr = cm->data; + *dstptr += msize; + return 0; +} + +static int compat_target_to_user(struct ebt_entry_target *t, + void __user **dstptr, + unsigned int *size) +{ + const struct xt_target *target = t->u.target; + struct compat_ebt_entry_mwt __user *cm = *dstptr; + int off = xt_compat_target_offset(target); + compat_uint_t tsize = t->target_size - off; + + BUG_ON(off >= t->target_size); + + if (copy_to_user(cm->u.name, target->name, + strlen(target->name) + 1) || put_user(tsize, &cm->match_size)) + return -EFAULT; + + if (target->compat_to_user) { + if (target->compat_to_user(cm->data, t->data)) + return -EFAULT; + } else if (copy_to_user(cm->data, t->data, tsize)) + return -EFAULT; + + *size -= ebt_compat_entry_padsize() + off; + *dstptr = cm->data; + *dstptr += tsize; + return 0; +} + +static int compat_watcher_to_user(struct ebt_entry_watcher *w, + void __user **dstptr, + unsigned int *size) +{ + return compat_target_to_user((struct ebt_entry_target *)w, + dstptr, size); +} + +static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr, + unsigned int *size) +{ + struct ebt_entry_target *t; + struct ebt_entry __user *ce; + u32 watchers_offset, target_offset, next_offset; + compat_uint_t origsize; + int ret; + + if (e->bitmask == 0) { + if (*size < sizeof(struct ebt_entries)) + return -EINVAL; + if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries))) + return -EFAULT; + + *dstptr += sizeof(struct ebt_entries); + *size -= sizeof(struct ebt_entries); + return 0; + } + + if (*size < sizeof(*ce)) + return -EINVAL; + + ce = (struct ebt_entry __user *)*dstptr; + if (copy_to_user(ce, e, sizeof(*ce))) + return -EFAULT; + + origsize = *size; + *dstptr += sizeof(*ce); + + ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size); + if (ret) + return ret; + watchers_offset = e->watchers_offset - (origsize - *size); + + ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size); + if (ret) + return ret; + target_offset = e->target_offset - (origsize - *size); + + t = (struct ebt_entry_target *) ((char *) e + e->target_offset); + + ret = compat_target_to_user(t, dstptr, size); + if (ret) + return ret; + next_offset = e->next_offset - (origsize - *size); + + if (put_user(watchers_offset, &ce->watchers_offset) || + put_user(target_offset, &ce->target_offset) || + put_user(next_offset, &ce->next_offset)) + return -EFAULT; + + *size -= sizeof(*ce); + return 0; +} + +static int compat_calc_match(struct ebt_entry_match *m, int *off) +{ + *off += ebt_compat_match_offset(m->u.match, m->match_size); + *off += ebt_compat_entry_padsize(); + return 0; +} + +static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off) +{ + *off += xt_compat_target_offset(w->u.watcher); + *off += ebt_compat_entry_padsize(); + return 0; +} + +static int compat_calc_entry(const struct ebt_entry *e, + const struct ebt_table_info *info, + const void *base, + struct compat_ebt_replace *newinfo) +{ + const struct ebt_entry_target *t; + unsigned int entry_offset; + int off, ret, i; + + if (e->bitmask == 0) + return 0; + + off = 0; + entry_offset = (void *)e - base; + + EBT_MATCH_ITERATE(e, compat_calc_match, &off); + EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off); + + t = (const struct ebt_entry_target *) ((char *) e + e->target_offset); + + off += xt_compat_target_offset(t->u.target); + off += ebt_compat_entry_padsize(); + + newinfo->entries_size -= off; + + ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off); + if (ret) + return ret; + + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + const void *hookptr = info->hook_entry[i]; + if (info->hook_entry[i] && + (e < (struct ebt_entry *)(base - hookptr))) { + newinfo->hook_entry[i] -= off; + pr_debug("0x%08X -> 0x%08X\n", + newinfo->hook_entry[i] + off, + newinfo->hook_entry[i]); + } + } + + return 0; +} + + +static int compat_table_info(const struct ebt_table_info *info, + struct compat_ebt_replace *newinfo) +{ + unsigned int size = info->entries_size; + const void *entries = info->entries; + + newinfo->entries_size = size; + + return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info, + entries, newinfo); +} + +static int compat_copy_everything_to_user(struct ebt_table *t, + void __user *user, int *len, int cmd) +{ + struct compat_ebt_replace repl, tmp; + struct ebt_counter *oldcounters; + struct ebt_table_info tinfo; + int ret; + void __user *pos; + + memset(&tinfo, 0, sizeof(tinfo)); + + if (cmd == EBT_SO_GET_ENTRIES) { + tinfo.entries_size = t->private->entries_size; + tinfo.nentries = t->private->nentries; + tinfo.entries = t->private->entries; + oldcounters = t->private->counters; + } else { + tinfo.entries_size = t->table->entries_size; + tinfo.nentries = t->table->nentries; + tinfo.entries = t->table->entries; + oldcounters = t->table->counters; + } + + if (copy_from_user(&tmp, user, sizeof(tmp))) + return -EFAULT; + + if (tmp.nentries != tinfo.nentries || + (tmp.num_counters && tmp.num_counters != tinfo.nentries)) + return -EINVAL; + + memcpy(&repl, &tmp, sizeof(repl)); + if (cmd == EBT_SO_GET_ENTRIES) + ret = compat_table_info(t->private, &repl); + else + ret = compat_table_info(&tinfo, &repl); + if (ret) + return ret; + + if (*len != sizeof(tmp) + repl.entries_size + + (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) { + pr_err("wrong size: *len %d, entries_size %u, replsz %d\n", + *len, tinfo.entries_size, repl.entries_size); + return -EINVAL; + } + + /* userspace might not need the counters */ + ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters), + tmp.num_counters, tinfo.nentries); + if (ret) + return ret; + + pos = compat_ptr(tmp.entries); + return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size, + compat_copy_entry_to_user, &pos, &tmp.entries_size); +} + +struct ebt_entries_buf_state { + char *buf_kern_start; /* kernel buffer to copy (translated) data to */ + u32 buf_kern_len; /* total size of kernel buffer */ + u32 buf_kern_offset; /* amount of data copied so far */ + u32 buf_user_offset; /* read position in userspace buffer */ +}; + +static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz) +{ + state->buf_kern_offset += sz; + return state->buf_kern_offset >= sz ? 0 : -EINVAL; +} + +static int ebt_buf_add(struct ebt_entries_buf_state *state, + void *data, unsigned int sz) +{ + if (state->buf_kern_start == NULL) + goto count_only; + + BUG_ON(state->buf_kern_offset + sz > state->buf_kern_len); + + memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz); + + count_only: + state->buf_user_offset += sz; + return ebt_buf_count(state, sz); +} + +static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz) +{ + char *b = state->buf_kern_start; + + BUG_ON(b && state->buf_kern_offset > state->buf_kern_len); + + if (b != NULL && sz > 0) + memset(b + state->buf_kern_offset, 0, sz); + /* do not adjust ->buf_user_offset here, we added kernel-side padding */ + return ebt_buf_count(state, sz); +} + +enum compat_mwt { + EBT_COMPAT_MATCH, + EBT_COMPAT_WATCHER, + EBT_COMPAT_TARGET, +}; + +static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt, + enum compat_mwt compat_mwt, + struct ebt_entries_buf_state *state, + const unsigned char *base) +{ + char name[EBT_FUNCTION_MAXNAMELEN]; + struct xt_match *match; + struct xt_target *wt; + void *dst = NULL; + int off, pad = 0, ret = 0; + unsigned int size_kern, entry_offset, match_size = mwt->match_size; + + strlcpy(name, mwt->u.name, sizeof(name)); + + if (state->buf_kern_start) + dst = state->buf_kern_start + state->buf_kern_offset; + + entry_offset = (unsigned char *) mwt - base; + switch (compat_mwt) { + case EBT_COMPAT_MATCH: + match = try_then_request_module(xt_find_match(NFPROTO_BRIDGE, + name, 0), "ebt_%s", name); + if (match == NULL) + return -ENOENT; + if (IS_ERR(match)) + return PTR_ERR(match); + + off = ebt_compat_match_offset(match, match_size); + if (dst) { + if (match->compat_from_user) + match->compat_from_user(dst, mwt->data); + else + memcpy(dst, mwt->data, match_size); + } + + size_kern = match->matchsize; + if (unlikely(size_kern == -1)) + size_kern = match_size; + module_put(match->me); + break; + case EBT_COMPAT_WATCHER: /* fallthrough */ + case EBT_COMPAT_TARGET: + wt = try_then_request_module(xt_find_target(NFPROTO_BRIDGE, + name, 0), "ebt_%s", name); + if (wt == NULL) + return -ENOENT; + if (IS_ERR(wt)) + return PTR_ERR(wt); + off = xt_compat_target_offset(wt); + + if (dst) { + if (wt->compat_from_user) + wt->compat_from_user(dst, mwt->data); + else + memcpy(dst, mwt->data, match_size); + } + + size_kern = wt->targetsize; + module_put(wt->me); + break; + } + + if (!dst) { + ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, + off + ebt_compat_entry_padsize()); + if (ret < 0) + return ret; + } + + state->buf_kern_offset += match_size + off; + state->buf_user_offset += match_size; + pad = XT_ALIGN(size_kern) - size_kern; + + if (pad > 0 && dst) { + BUG_ON(state->buf_kern_len <= pad); + BUG_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad); + memset(dst + size_kern, 0, pad); + } + return off + match_size; +} + +/* + * return size of all matches, watchers or target, including necessary + * alignment and padding. + */ +static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32, + unsigned int size_left, enum compat_mwt type, + struct ebt_entries_buf_state *state, const void *base) +{ + int growth = 0; + char *buf; + + if (size_left == 0) + return 0; + + buf = (char *) match32; + + while (size_left >= sizeof(*match32)) { + struct ebt_entry_match *match_kern; + int ret; + + match_kern = (struct ebt_entry_match *) state->buf_kern_start; + if (match_kern) { + char *tmp; + tmp = state->buf_kern_start + state->buf_kern_offset; + match_kern = (struct ebt_entry_match *) tmp; + } + ret = ebt_buf_add(state, buf, sizeof(*match32)); + if (ret < 0) + return ret; + size_left -= sizeof(*match32); + + /* add padding before match->data (if any) */ + ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize()); + if (ret < 0) + return ret; + + if (match32->match_size > size_left) + return -EINVAL; + + size_left -= match32->match_size; + + ret = compat_mtw_from_user(match32, type, state, base); + if (ret < 0) + return ret; + + BUG_ON(ret < match32->match_size); + growth += ret - match32->match_size; + growth += ebt_compat_entry_padsize(); + + buf += sizeof(*match32); + buf += match32->match_size; + + if (match_kern) + match_kern->match_size = ret; + + WARN_ON(type == EBT_COMPAT_TARGET && size_left); + match32 = (struct compat_ebt_entry_mwt *) buf; + } + + return growth; +} + +#define EBT_COMPAT_WATCHER_ITERATE(e, fn, args...) \ +({ \ + unsigned int __i; \ + int __ret = 0; \ + struct compat_ebt_entry_mwt *__watcher; \ + \ + for (__i = e->watchers_offset; \ + __i < (e)->target_offset; \ + __i += __watcher->watcher_size + \ + sizeof(struct compat_ebt_entry_mwt)) { \ + __watcher = (void *)(e) + __i; \ + __ret = fn(__watcher , ## args); \ + if (__ret != 0) \ + break; \ + } \ + if (__ret == 0) { \ + if (__i != (e)->target_offset) \ + __ret = -EINVAL; \ + } \ + __ret; \ +}) + +#define EBT_COMPAT_MATCH_ITERATE(e, fn, args...) \ +({ \ + unsigned int __i; \ + int __ret = 0; \ + struct compat_ebt_entry_mwt *__match; \ + \ + for (__i = sizeof(struct ebt_entry); \ + __i < (e)->watchers_offset; \ + __i += __match->match_size + \ + sizeof(struct compat_ebt_entry_mwt)) { \ + __match = (void *)(e) + __i; \ + __ret = fn(__match , ## args); \ + if (__ret != 0) \ + break; \ + } \ + if (__ret == 0) { \ + if (__i != (e)->watchers_offset) \ + __ret = -EINVAL; \ + } \ + __ret; \ +}) + +/* called for all ebt_entry structures. */ +static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base, + unsigned int *total, + struct ebt_entries_buf_state *state) +{ + unsigned int i, j, startoff, new_offset = 0; + /* stores match/watchers/targets & offset of next struct ebt_entry: */ + unsigned int offsets[4]; + unsigned int *offsets_update = NULL; + int ret; + char *buf_start; + + if (*total < sizeof(struct ebt_entries)) + return -EINVAL; + + if (!entry->bitmask) { + *total -= sizeof(struct ebt_entries); + return ebt_buf_add(state, entry, sizeof(struct ebt_entries)); + } + if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry)) + return -EINVAL; + + startoff = state->buf_user_offset; + /* pull in most part of ebt_entry, it does not need to be changed. */ + ret = ebt_buf_add(state, entry, + offsetof(struct ebt_entry, watchers_offset)); + if (ret < 0) + return ret; + + offsets[0] = sizeof(struct ebt_entry); /* matches come first */ + memcpy(&offsets[1], &entry->watchers_offset, + sizeof(offsets) - sizeof(offsets[0])); + + if (state->buf_kern_start) { + buf_start = state->buf_kern_start + state->buf_kern_offset; + offsets_update = (unsigned int *) buf_start; + } + ret = ebt_buf_add(state, &offsets[1], + sizeof(offsets) - sizeof(offsets[0])); + if (ret < 0) + return ret; + buf_start = (char *) entry; + /* + * 0: matches offset, always follows ebt_entry. + * 1: watchers offset, from ebt_entry structure + * 2: target offset, from ebt_entry structure + * 3: next ebt_entry offset, from ebt_entry structure + * + * offsets are relative to beginning of struct ebt_entry (i.e., 0). + */ + for (i = 0, j = 1 ; j < 4 ; j++, i++) { + struct compat_ebt_entry_mwt *match32; + unsigned int size; + char *buf = buf_start; + + buf = buf_start + offsets[i]; + if (offsets[i] > offsets[j]) + return -EINVAL; + + match32 = (struct compat_ebt_entry_mwt *) buf; + size = offsets[j] - offsets[i]; + ret = ebt_size_mwt(match32, size, i, state, base); + if (ret < 0) + return ret; + new_offset += ret; + if (offsets_update && new_offset) { + pr_debug("ebtables: change offset %d to %d\n", + offsets_update[i], offsets[j] + new_offset); + offsets_update[i] = offsets[j] + new_offset; + } + } + + startoff = state->buf_user_offset - startoff; + + BUG_ON(*total < startoff); + *total -= startoff; + return 0; +} + +/* + * repl->entries_size is the size of the ebt_entry blob in userspace. + * It might need more memory when copied to a 64 bit kernel in case + * userspace is 32-bit. So, first task: find out how much memory is needed. + * + * Called before validation is performed. + */ +static int compat_copy_entries(unsigned char *data, unsigned int size_user, + struct ebt_entries_buf_state *state) +{ + unsigned int size_remaining = size_user; + int ret; + + ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data, + &size_remaining, state); + if (ret < 0) + return ret; + + WARN_ON(size_remaining); + return state->buf_kern_offset; +} + + +static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl, + void __user *user, unsigned int len) +{ + struct compat_ebt_replace tmp; + int i; + + if (len < sizeof(tmp)) + return -EINVAL; + + if (copy_from_user(&tmp, user, sizeof(tmp))) + return -EFAULT; + + if (len != sizeof(tmp) + tmp.entries_size) + return -EINVAL; + + if (tmp.entries_size == 0) + return -EINVAL; + + if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / + NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) + return -ENOMEM; + if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) + return -ENOMEM; + + memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry)); + + /* starting with hook_entry, 32 vs. 64 bit structures are different */ + for (i = 0; i < NF_BR_NUMHOOKS; i++) + repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]); + + repl->num_counters = tmp.num_counters; + repl->counters = compat_ptr(tmp.counters); + repl->entries = compat_ptr(tmp.entries); + return 0; +} + +static int compat_do_replace(struct net *net, void __user *user, + unsigned int len) +{ + int ret, i, countersize, size64; + struct ebt_table_info *newinfo; + struct ebt_replace tmp; + struct ebt_entries_buf_state state; + void *entries_tmp; + + ret = compat_copy_ebt_replace_from_user(&tmp, user, len); + if (ret) { + /* try real handler in case userland supplied needed padding */ + if (ret == -EINVAL && do_replace(net, user, len) == 0) + ret = 0; + return ret; + } + + countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; + newinfo = vmalloc(sizeof(*newinfo) + countersize); + if (!newinfo) + return -ENOMEM; + + if (countersize) + memset(newinfo->counters, 0, countersize); + + memset(&state, 0, sizeof(state)); + + newinfo->entries = vmalloc(tmp.entries_size); + if (!newinfo->entries) { + ret = -ENOMEM; + goto free_newinfo; + } + if (copy_from_user( + newinfo->entries, tmp.entries, tmp.entries_size) != 0) { + ret = -EFAULT; + goto free_entries; + } + + entries_tmp = newinfo->entries; + + xt_compat_lock(NFPROTO_BRIDGE); + + ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); + if (ret < 0) + goto out_unlock; + + pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n", + tmp.entries_size, state.buf_kern_offset, state.buf_user_offset, + xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size)); + + size64 = ret; + newinfo->entries = vmalloc(size64); + if (!newinfo->entries) { + vfree(entries_tmp); + ret = -ENOMEM; + goto out_unlock; + } + + memset(&state, 0, sizeof(state)); + state.buf_kern_start = newinfo->entries; + state.buf_kern_len = size64; + + ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); + BUG_ON(ret < 0); /* parses same data again */ + + vfree(entries_tmp); + tmp.entries_size = size64; + + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + char __user *usrptr; + if (tmp.hook_entry[i]) { + unsigned int delta; + usrptr = (char __user *) tmp.hook_entry[i]; + delta = usrptr - tmp.entries; + usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta); + tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr; + } + } + + xt_compat_flush_offsets(NFPROTO_BRIDGE); + xt_compat_unlock(NFPROTO_BRIDGE); + + ret = do_replace_finish(net, &tmp, newinfo); + if (ret == 0) + return ret; +free_entries: + vfree(newinfo->entries); +free_newinfo: + vfree(newinfo); + return ret; +out_unlock: + xt_compat_flush_offsets(NFPROTO_BRIDGE); + xt_compat_unlock(NFPROTO_BRIDGE); + goto free_entries; +} + +static int compat_update_counters(struct net *net, void __user *user, + unsigned int len) +{ + struct compat_ebt_replace hlp; + + if (copy_from_user(&hlp, user, sizeof(hlp))) + return -EFAULT; + + /* try real handler in case userland supplied needed padding */ + if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) + return update_counters(net, user, len); + + return do_update_counters(net, hlp.name, compat_ptr(hlp.counters), + hlp.num_counters, user, len); +} + +static int compat_do_ebt_set_ctl(struct sock *sk, + int cmd, void __user *user, unsigned int len) +{ + int ret; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + switch (cmd) { + case EBT_SO_SET_ENTRIES: + ret = compat_do_replace(sock_net(sk), user, len); + break; + case EBT_SO_SET_COUNTERS: + ret = compat_update_counters(sock_net(sk), user, len); + break; + default: + ret = -EINVAL; + } + return ret; +} + +static int compat_do_ebt_get_ctl(struct sock *sk, int cmd, + void __user *user, int *len) +{ + int ret; + struct compat_ebt_replace tmp; + struct ebt_table *t; + + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + /* try real handler in case userland supplied needed padding */ + if ((cmd == EBT_SO_GET_INFO || + cmd == EBT_SO_GET_INIT_INFO) && *len != sizeof(tmp)) + return do_ebt_get_ctl(sk, cmd, user, len); + + if (copy_from_user(&tmp, user, sizeof(tmp))) + return -EFAULT; + + t = find_table_lock(sock_net(sk), tmp.name, &ret, &ebt_mutex); + if (!t) + return ret; + + xt_compat_lock(NFPROTO_BRIDGE); + switch (cmd) { + case EBT_SO_GET_INFO: + tmp.nentries = t->private->nentries; + ret = compat_table_info(t->private, &tmp); + if (ret) + goto out; + tmp.valid_hooks = t->valid_hooks; + + if (copy_to_user(user, &tmp, *len) != 0) { + ret = -EFAULT; + break; + } + ret = 0; + break; + case EBT_SO_GET_INIT_INFO: + tmp.nentries = t->table->nentries; + tmp.entries_size = t->table->entries_size; + tmp.valid_hooks = t->table->valid_hooks; + + if (copy_to_user(user, &tmp, *len) != 0) { + ret = -EFAULT; + break; + } + ret = 0; + break; + case EBT_SO_GET_ENTRIES: + case EBT_SO_GET_INIT_ENTRIES: + /* + * try real handler first in case of userland-side padding. + * in case we are dealing with an 'ordinary' 32 bit binary + * without 64bit compatibility padding, this will fail right + * after copy_from_user when the *len argument is validated. + * + * the compat_ variant needs to do one pass over the kernel + * data set to adjust for size differences before it the check. + */ + if (copy_everything_to_user(t, user, len, cmd) == 0) + ret = 0; + else + ret = compat_copy_everything_to_user(t, user, len, cmd); + break; + default: + ret = -EINVAL; + } + out: + xt_compat_flush_offsets(NFPROTO_BRIDGE); + xt_compat_unlock(NFPROTO_BRIDGE); + mutex_unlock(&ebt_mutex); + return ret; +} +#endif + static struct nf_sockopt_ops ebt_sockopts = { .pf = PF_INET, .set_optmin = EBT_BASE_CTL, .set_optmax = EBT_SO_SET_MAX + 1, .set = do_ebt_set_ctl, +#ifdef CONFIG_COMPAT + .compat_set = compat_do_ebt_set_ctl, +#endif .get_optmin = EBT_BASE_CTL, .get_optmax = EBT_SO_GET_MAX + 1, .get = do_ebt_get_ctl, +#ifdef CONFIG_COMPAT + .compat_get = compat_do_ebt_get_ctl, +#endif .owner = THIS_MODULE, }; |