From 9fa492cdc160cd27ce1046cb36f47d3b2b1efa21 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Wed, 20 Sep 2006 12:05:37 -0700 Subject: [NETFILTER]: x_tables: simplify compat API Split the xt_compat_match/xt_compat_target into smaller type-safe functions performing just one operation. Handle all alignment and size-related conversions centrally in these function instead of requiring each module to implement a full-blown conversion function. Replace ->compat callback by ->compat_from_user and ->compat_to_user callbacks, responsible for converting just a single private structure. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/ip_tables.c | 115 +++++++++-------------------------------- 1 file changed, 24 insertions(+), 91 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 673581db986..800067d69a9 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -942,73 +942,28 @@ static short compat_calc_jump(u_int16_t offset) return delta; } -struct compat_ipt_standard_target +static void compat_standard_from_user(void *dst, void *src) { - struct compat_xt_entry_target target; - compat_int_t verdict; -}; - -struct compat_ipt_standard -{ - struct compat_ipt_entry entry; - struct compat_ipt_standard_target target; -}; + int v = *(compat_int_t *)src; -#define IPT_ST_LEN XT_ALIGN(sizeof(struct ipt_standard_target)) -#define IPT_ST_COMPAT_LEN COMPAT_XT_ALIGN(sizeof(struct compat_ipt_standard_target)) -#define IPT_ST_OFFSET (IPT_ST_LEN - IPT_ST_COMPAT_LEN) + if (v > 0) + v += compat_calc_jump(v); + memcpy(dst, &v, sizeof(v)); +} -static int compat_ipt_standard_fn(void *target, - void **dstptr, int *size, int convert) +static int compat_standard_to_user(void __user *dst, void *src) { - struct compat_ipt_standard_target compat_st, *pcompat_st; - struct ipt_standard_target st, *pst; - int ret; + compat_int_t cv = *(int *)src; - ret = 0; - switch (convert) { - case COMPAT_TO_USER: - pst = target; - memcpy(&compat_st.target, &pst->target, - sizeof(compat_st.target)); - compat_st.verdict = pst->verdict; - if (compat_st.verdict > 0) - compat_st.verdict -= - compat_calc_jump(compat_st.verdict); - compat_st.target.u.user.target_size = IPT_ST_COMPAT_LEN; - if (copy_to_user(*dstptr, &compat_st, IPT_ST_COMPAT_LEN)) - ret = -EFAULT; - *size -= IPT_ST_OFFSET; - *dstptr += IPT_ST_COMPAT_LEN; - break; - case COMPAT_FROM_USER: - pcompat_st = target; - memcpy(&st.target, &pcompat_st->target, IPT_ST_COMPAT_LEN); - st.verdict = pcompat_st->verdict; - if (st.verdict > 0) - st.verdict += compat_calc_jump(st.verdict); - st.target.u.user.target_size = IPT_ST_LEN; - memcpy(*dstptr, &st, IPT_ST_LEN); - *size += IPT_ST_OFFSET; - *dstptr += IPT_ST_LEN; - break; - case COMPAT_CALC_SIZE: - *size += IPT_ST_OFFSET; - break; - default: - ret = -ENOPROTOOPT; - break; - } - return ret; + if (cv > 0) + cv -= compat_calc_jump(cv); + return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; } static inline int compat_calc_match(struct ipt_entry_match *m, int * size) { - if (m->u.kernel.match->compat) - m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE); - else - xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE); + *size += xt_compat_match_offset(m->u.kernel.match); return 0; } @@ -1023,10 +978,7 @@ static int compat_calc_entry(struct ipt_entry *e, struct xt_table_info *info, entry_offset = (void *)e - base; IPT_MATCH_ITERATE(e, compat_calc_match, &off); t = ipt_get_target(e); - if (t->u.kernel.target->compat) - t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE); - else - xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE); + off += xt_compat_target_offset(t->u.kernel.target); newinfo->size -= off; ret = compat_add_offset(entry_offset, off); if (ret) @@ -1412,17 +1364,13 @@ struct compat_ipt_replace { }; static inline int compat_copy_match_to_user(struct ipt_entry_match *m, - void __user **dstptr, compat_uint_t *size) + void * __user *dstptr, compat_uint_t *size) { - if (m->u.kernel.match->compat) - return m->u.kernel.match->compat(m, dstptr, size, - COMPAT_TO_USER); - else - return xt_compat_match(m, dstptr, size, COMPAT_TO_USER); + return xt_compat_match_to_user(m, dstptr, size); } static int compat_copy_entry_to_user(struct ipt_entry *e, - void __user **dstptr, compat_uint_t *size) + void * __user *dstptr, compat_uint_t *size) { struct ipt_entry_target __user *t; struct compat_ipt_entry __user *ce; @@ -1442,11 +1390,7 @@ static int compat_copy_entry_to_user(struct ipt_entry *e, if (ret) goto out; t = ipt_get_target(e); - if (t->u.kernel.target->compat) - ret = t->u.kernel.target->compat(t, dstptr, size, - COMPAT_TO_USER); - else - ret = xt_compat_target(t, dstptr, size, COMPAT_TO_USER); + ret = xt_compat_target_to_user(t, dstptr, size); if (ret) goto out; ret = -EFAULT; @@ -1478,11 +1422,7 @@ compat_check_calc_match(struct ipt_entry_match *m, return match ? PTR_ERR(match) : -ENOENT; } m->u.kernel.match = match; - - if (m->u.kernel.match->compat) - m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE); - else - xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE); + *size += xt_compat_match_offset(match); (*i)++; return 0; @@ -1543,10 +1483,7 @@ check_compat_entry_size_and_hooks(struct ipt_entry *e, } t->u.kernel.target = target; - if (t->u.kernel.target->compat) - t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE); - else - xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE); + off += xt_compat_target_offset(target); *size += off; ret = compat_add_offset(entry_offset, off); if (ret) @@ -1584,10 +1521,7 @@ static inline int compat_copy_match_from_user(struct ipt_entry_match *m, dm = (struct ipt_entry_match *)*dstptr; match = m->u.kernel.match; - if (match->compat) - match->compat(m, dstptr, size, COMPAT_FROM_USER); - else - xt_compat_match(m, dstptr, size, COMPAT_FROM_USER); + xt_compat_match_from_user(m, dstptr, size); ret = xt_check_match(match, AF_INET, dm->u.match_size - sizeof(*dm), name, hookmask, ip->proto, @@ -1635,10 +1569,7 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr, de->target_offset = e->target_offset - (origsize - *size); t = ipt_get_target(e); target = t->u.kernel.target; - if (target->compat) - target->compat(t, dstptr, size, COMPAT_FROM_USER); - else - xt_compat_target(t, dstptr, size, COMPAT_FROM_USER); + xt_compat_target_from_user(t, dstptr, size); de->next_offset = e->next_offset - (origsize - *size); for (h = 0; h < NF_IP_NUMHOOKS; h++) { @@ -2205,7 +2136,9 @@ static struct ipt_target ipt_standard_target = { .targetsize = sizeof(int), .family = AF_INET, #ifdef CONFIG_COMPAT - .compat = &compat_ipt_standard_fn, + .compatsize = sizeof(compat_int_t), + .compat_from_user = compat_standard_from_user, + .compat_to_user = compat_standard_to_user, #endif }; -- cgit v1.2.3