From 70f8785b9ee364828e9a0f38275283024df621c2 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Thu, 6 Dec 2018 15:44:57 +0100 Subject: [PATCH] zones: add zone identifying local traffic in raw OUTPUT chain Add zone chains identifying local generated traffic; either by configuring a loopback device or as subnet a loopback address; in the raw OUTPUT chain as local generated traffic is passing this chain. This allows helpers to be used for local generated traffic. Signed-off-by: Alin Nastac Signed-off-by: Hans Dedecker Acked-by: Jo-Philipp Wich --- utils.c | 38 ++++++++++++++++++++++++++++++++++++++ utils.h | 5 +++++ zones.c | 14 +++++++++----- 3 files changed, 52 insertions(+), 5 deletions(-) diff --git a/utils.c b/utils.c index 684b2c3..7f09787 100644 --- a/utils.c +++ b/utils.c @@ -17,6 +17,10 @@ */ #define _GNU_SOURCE + +#include +#include + #include "utils.h" #include "options.h" @@ -935,3 +939,37 @@ fw3_protoname(void *proto) return pe->p_name; } + +bool +fw3_check_loopback_dev(const char *name) +{ + struct ifreq ifr; + int s = socket(AF_LOCAL, SOCK_DGRAM, 0); + bool rv = false; + + memset(&ifr, 0, sizeof(ifr)); + strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name) - 1); + + if (s < 0 || ioctl(s, SIOCGIFFLAGS, &ifr) < 0) + goto out; + + if (ifr.ifr_flags & IFF_LOOPBACK) + rv = true; +out: + return rv; +} + +bool +fw3_check_loopback_addr(struct fw3_address *addr) +{ + if (addr->family == FW3_FAMILY_V4 && + (ntohl(addr->address.v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) + return true; + + if (addr->family == FW3_FAMILY_V6 && !addr->range && + fw3_netmask2bitlen(FW3_FAMILY_V6, &addr->mask.v6) == 128 && + IN6_IS_ADDR_LOOPBACK(&addr->address.v6)) + return true; + + return false; +} diff --git a/utils.h b/utils.h index c8ab0e5..1ada0dd 100644 --- a/utils.h +++ b/utils.h @@ -44,6 +44,8 @@ extern bool fw3_pr_debug; +struct fw3_address; + void warn_elem(struct uci_element *e, const char *format, ...); void warn(const char *format, ...); void error(const char *format, ...); @@ -120,4 +122,7 @@ bool fw3_attr_parse_name_type(struct blob_attr *entry, const char **name, const const char * fw3_protoname(void *proto); +bool fw3_check_loopback_dev(const char *name); + +bool fw3_check_loopback_addr(struct fw3_address *addr); #endif diff --git a/zones.c b/zones.c index 505ab20..4f2b1e4 100644 --- a/zones.c +++ b/zones.c @@ -98,7 +98,6 @@ const struct fw3_option fw3_zone_opts[] = { { } }; - static void check_policy(struct uci_element *e, enum fw3_flag *pol, enum fw3_flag def, const char *name) @@ -557,22 +556,27 @@ print_interface_rule(struct fw3_ipt_handle *handle, struct fw3_state *state, } else if (handle->table == FW3_TABLE_RAW) { + bool loopback_dev = (dev != NULL && !dev->any && + !dev->invert && fw3_check_loopback_dev(dev->name)); + char *chain = loopback_dev || (sub != NULL && !sub->invert && fw3_check_loopback_addr(sub)) ? + "OUTPUT" : "PREROUTING"; + if (has(zone->flags, handle->family, FW3_FLAG_HELPER)) { - r = fw3_ipt_rule_create(handle, NULL, dev, NULL, sub, NULL); + r = fw3_ipt_rule_create(handle, NULL, loopback_dev ? NULL : dev, NULL, sub, NULL); fw3_ipt_rule_comment(r, "%s CT helper assignment", zone->name); fw3_ipt_rule_target(r, "zone_%s_helper", zone->name); fw3_ipt_rule_extra(r, zone->extra_src); - fw3_ipt_rule_replace(r, "PREROUTING"); + fw3_ipt_rule_replace(r, chain); } if (has(zone->flags, handle->family, FW3_FLAG_NOTRACK)) { - r = fw3_ipt_rule_create(handle, NULL, dev, NULL, sub, NULL); + r = fw3_ipt_rule_create(handle, NULL, loopback_dev ? NULL : dev, NULL, sub, NULL); fw3_ipt_rule_comment(r, "%s CT bypass", zone->name); fw3_ipt_rule_target(r, "zone_%s_notrack", zone->name); fw3_ipt_rule_extra(r, zone->extra_src); - fw3_ipt_rule_replace(r, "PREROUTING"); + fw3_ipt_rule_replace(r, chain); } } } -- 2.25.1