commit 9b8cb7564a53865bf0e239bbc3e057de70edf65d Author: Dan Williams Date: Sat Feb 25 22:02:03 2017 -0600 libiptc: don't set_changed() when checking rules with module jumps Checking a rule that includes a jump to a module-based target currently sets the "changed" flag on the handle, which then causes TC_COMMIT() to run through the whole SO_SET_REPLACE/SO_SET_ADD_COUNTERS path. This seems wrong for simply checking rules, an operation which is documented as "...does not alter the existing iptables configuration..." but yet it clearly could do so. Fix that by ensuring that rule check operations for module targets don't set the changed flag, and thus exit early from TC_COMMIT(). Signed-off-by: Dan Williams Signed-off-by: Pablo Neira Ayuso diff --git a/libiptc/libiptc.c b/libiptc/libiptc.c index 2c66d04..a6e7057 100644 --- a/libiptc/libiptc.c +++ b/libiptc/libiptc.c @@ -1686,7 +1686,8 @@ iptcc_standard_map(struct rule_head *r, int verdict) static int iptcc_map_target(struct xtc_handle *const handle, - struct rule_head *r) + struct rule_head *r, + bool dry_run) { STRUCT_ENTRY *e = r->entry; STRUCT_ENTRY_TARGET *t = GET_TARGET(e); @@ -1731,7 +1732,8 @@ iptcc_map_target(struct xtc_handle *const handle, 0, FUNCTION_MAXNAMELEN - 1 - strlen(t->u.user.name)); r->type = IPTCC_R_MODULE; - set_changed(handle); + if (!dry_run) + set_changed(handle); return 1; } @@ -1781,7 +1783,7 @@ TC_INSERT_ENTRY(const IPT_CHAINLABEL chain, memcpy(r->entry, e, e->next_offset); r->counter_map.maptype = COUNTER_MAP_SET; - if (!iptcc_map_target(handle, r)) { + if (!iptcc_map_target(handle, r, false)) { free(r); return 0; } @@ -1831,7 +1833,7 @@ TC_REPLACE_ENTRY(const IPT_CHAINLABEL chain, memcpy(r->entry, e, e->next_offset); r->counter_map.maptype = COUNTER_MAP_SET; - if (!iptcc_map_target(handle, r)) { + if (!iptcc_map_target(handle, r, false)) { free(r); return 0; } @@ -1870,7 +1872,7 @@ TC_APPEND_ENTRY(const IPT_CHAINLABEL chain, memcpy(r->entry, e, e->next_offset); r->counter_map.maptype = COUNTER_MAP_SET; - if (!iptcc_map_target(handle, r)) { + if (!iptcc_map_target(handle, r, false)) { DEBUGP("unable to map target of rule for chain `%s'\n", chain); free(r); return 0; @@ -1976,7 +1978,7 @@ static int delete_entry(const IPT_CHAINLABEL chain, const STRUCT_ENTRY *origfw, memcpy(r->entry, origfw, origfw->next_offset); r->counter_map.maptype = COUNTER_MAP_NOMAP; - if (!iptcc_map_target(handle, r)) { + if (!iptcc_map_target(handle, r, dry_run)) { DEBUGP("unable to map target of rule for chain `%s'\n", chain); free(r); return 0;