From 31456301f514e3e04f61930bb00f6b2d99b4d067 Mon Sep 17 00:00:00 2001 From: Jo-Philipp Wich Date: Sun, 6 Apr 2014 22:25:14 +0200 Subject: [PATCH] Initial support for "config nat" rules - this allows configuring zone-independant SNAT and MASQUERADE rules --- CMakeLists.txt | 2 +- main.c | 8 +- options.c | 5 +- options.h | 54 +++++-- redirects.c | 4 +- snats.c | 375 +++++++++++++++++++++++++++++++++++++++++++++++++ snats.h | 36 +++++ 7 files changed, 469 insertions(+), 15 deletions(-) create mode 100644 snats.c create mode 100644 snats.h diff --git a/CMakeLists.txt b/CMakeLists.txt index 4a85e07..a57cb7b 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -37,7 +37,7 @@ ELSE() ADD_DEFINITIONS(-DDISABLE_IPV6) ENDIF() -ADD_EXECUTABLE(firewall3 main.c options.c defaults.c zones.c forwards.c rules.c redirects.c utils.c ubus.c ipsets.c includes.c iptables.c) +ADD_EXECUTABLE(firewall3 main.c options.c defaults.c zones.c forwards.c rules.c redirects.c snats.c utils.c ubus.c ipsets.c includes.c iptables.c) TARGET_LINK_LIBRARIES(firewall3 uci ubox ubus xtables m dl ${iptc_libs} ${ext_libs}) SET(CMAKE_INSTALL_PREFIX /usr) diff --git a/main.c b/main.c index 32ff87d..c0180b2 100644 --- a/main.c +++ b/main.c @@ -1,7 +1,7 @@ /* * firewall3 - 3rd OpenWrt UCI firewall implementation * - * Copyright (C) 2013 Jo-Philipp Wich + * Copyright (C) 2013-2014 Jo-Philipp Wich * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -24,6 +24,7 @@ #include "zones.h" #include "rules.h" #include "redirects.h" +#include "snats.h" #include "forwards.h" #include "ipsets.h" #include "includes.h" @@ -102,6 +103,7 @@ build_state(bool runtime) fw3_load_zones(state, p); fw3_load_rules(state, p); fw3_load_redirects(state, p); + fw3_load_snats(state, p); fw3_load_forwards(state, p); fw3_load_includes(state, p); @@ -122,6 +124,9 @@ free_state(struct fw3_state *state) list_for_each_safe(cur, tmp, &state->redirects) fw3_free_redirect((struct fw3_redirect *)cur); + list_for_each_safe(cur, tmp, &state->snats) + fw3_free_snat((struct fw3_snat *)cur); + list_for_each_safe(cur, tmp, &state->forwards) fw3_free_forward((struct fw3_forward *)cur); @@ -275,6 +280,7 @@ start(void) fw3_print_default_head_rules(handle, cfg_state, false); fw3_print_rules(handle, cfg_state); fw3_print_redirects(handle, cfg_state); + fw3_print_snats(handle, cfg_state); fw3_print_forwards(handle, cfg_state); fw3_print_zone_rules(handle, cfg_state, false); fw3_print_default_tail_rules(handle, cfg_state, false); diff --git a/options.c b/options.c index 7e62ca6..4c42be0 100644 --- a/options.c +++ b/options.c @@ -1,7 +1,7 @@ /* * firewall3 - 3rd OpenWrt UCI firewall implementation * - * Copyright (C) 2013 Jo-Philipp Wich + * Copyright (C) 2013-2014 Jo-Philipp Wich * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -78,6 +78,7 @@ const char *fw3_flag_names[__FW3_FLAG_MAX] = { "MARK", "DNAT", "SNAT", + "MASQUERADE", "ACCEPT", "REJECT", @@ -164,7 +165,7 @@ bool fw3_parse_target(void *ptr, const char *val, bool is_list) { return parse_enum(ptr, val, &fw3_flag_names[FW3_FLAG_ACCEPT], - FW3_FLAG_ACCEPT, FW3_FLAG_SNAT); + FW3_FLAG_ACCEPT, FW3_FLAG_MASQUERADE); } bool diff --git a/options.h b/options.h index 07d57a4..b31f6b4 100644 --- a/options.h +++ b/options.h @@ -1,7 +1,7 @@ /* * firewall3 - 3rd OpenWrt UCI firewall implementation * - * Copyright (C) 2013 Jo-Philipp Wich + * Copyright (C) 2013-2014 Jo-Philipp Wich * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -71,14 +71,15 @@ enum fw3_flag FW3_FLAG_MARK = 10, FW3_FLAG_DNAT = 11, FW3_FLAG_SNAT = 12, - FW3_FLAG_SRC_ACCEPT = 13, - FW3_FLAG_SRC_REJECT = 14, - FW3_FLAG_SRC_DROP = 15, - FW3_FLAG_CUSTOM_CHAINS = 16, - FW3_FLAG_SYN_FLOOD = 17, - FW3_FLAG_MTU_FIX = 18, - FW3_FLAG_DROP_INVALID = 19, - FW3_FLAG_HOTPLUG = 20, + FW3_FLAG_MASQUERADE = 13, + FW3_FLAG_SRC_ACCEPT = 14, + FW3_FLAG_SRC_REJECT = 15, + FW3_FLAG_SRC_DROP = 16, + FW3_FLAG_CUSTOM_CHAINS = 17, + FW3_FLAG_SYN_FLOOD = 18, + FW3_FLAG_MTU_FIX = 19, + FW3_FLAG_DROP_INVALID = 20, + FW3_FLAG_HOTPLUG = 21, __FW3_FLAG_MAX }; @@ -394,6 +395,40 @@ struct fw3_redirect enum fw3_reflection_source reflection_src; }; +struct fw3_snat +{ + struct list_head list; + + bool enabled; + const char *name; + + enum fw3_family family; + + struct fw3_zone *_src; + + struct fw3_device src; + struct fw3_setmatch ipset; + + struct list_head proto; + + struct fw3_address ip_src; + struct fw3_port port_src; + + struct fw3_address ip_dest; + struct fw3_port port_dest; + + struct fw3_address ip_snat; + struct fw3_port port_snat; + + struct fw3_limit limit; + struct fw3_time time; + struct fw3_mark mark; + + enum fw3_flag target; + + const char *extra; +}; + struct fw3_forward { struct list_head list; @@ -456,6 +491,7 @@ struct fw3_state struct list_head zones; struct list_head rules; struct list_head redirects; + struct list_head snats; struct list_head forwards; struct list_head ipsets; struct list_head includes; diff --git a/redirects.c b/redirects.c index 18666a3..a21998b 100644 --- a/redirects.c +++ b/redirects.c @@ -1,7 +1,7 @@ /* * firewall3 - 3rd OpenWrt UCI firewall implementation * - * Copyright (C) 2013 Jo-Philipp Wich + * Copyright (C) 2013-2014 Jo-Philipp Wich * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -305,7 +305,7 @@ fw3_load_redirects(struct fw3_state *state, struct uci_package *p) warn_elem(e, "has no target specified, defaulting to DNAT"); redir->target = FW3_FLAG_DNAT; } - else if (redir->target < FW3_FLAG_DNAT) + else if (redir->target < FW3_FLAG_DNAT || redir->target > FW3_FLAG_SNAT) { warn_elem(e, "has invalid target specified, defaulting to DNAT"); redir->target = FW3_FLAG_DNAT; diff --git a/snats.c b/snats.c new file mode 100644 index 0000000..00fd57c --- /dev/null +++ b/snats.c @@ -0,0 +1,375 @@ +/* + * firewall3 - 3rd OpenWrt UCI firewall implementation + * + * Copyright (C) 2014 Jo-Philipp Wich + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "snats.h" + + +const struct fw3_option fw3_snat_opts[] = { + FW3_OPT("enabled", bool, snat, enabled), + + FW3_OPT("name", string, snat, name), + FW3_OPT("family", family, snat, family), + + FW3_OPT("src", device, snat, src), + + FW3_OPT("ipset", setmatch, snat, ipset), + + FW3_LIST("proto", protocol, snat, proto), + + FW3_OPT("src_ip", network, snat, ip_src), + FW3_OPT("src_port", port, snat, port_src), + + FW3_OPT("snat_ip", network, snat, ip_snat), + FW3_OPT("snat_port", port, snat, port_snat), + + FW3_OPT("dest_ip", network, snat, ip_dest), + FW3_OPT("dest_port", port, snat, port_dest), + + FW3_OPT("extra", string, snat, extra), + + FW3_OPT("limit", limit, snat, limit), + FW3_OPT("limit_burst", int, snat, limit.burst), + + FW3_OPT("utc_time", bool, snat, time.utc), + FW3_OPT("start_date", date, snat, time.datestart), + FW3_OPT("stop_date", date, snat, time.datestop), + FW3_OPT("start_time", time, snat, time.timestart), + FW3_OPT("stop_time", time, snat, time.timestop), + FW3_OPT("weekdays", weekdays, snat, time.weekdays), + FW3_OPT("monthdays", monthdays, snat, time.monthdays), + + FW3_OPT("mark", mark, snat, mark), + + FW3_OPT("target", target, snat, target), + + { } +}; + + +static bool +check_families(struct uci_element *e, struct fw3_snat *r) +{ + if (r->family == FW3_FAMILY_ANY) + return true; + + if (r->_src && r->_src->family && r->_src->family != r->family) + { + warn_elem(e, "refers to source zone with different family"); + return false; + } + + if (r->ipset.ptr && r->ipset.ptr->family && + r->ipset.ptr->family != r->family) + { + warn_elem(e, "refers to ipset with different family"); + return false; + } + + if (r->ip_src.family && r->ip_src.family != r->family) + { + warn_elem(e, "uses source ip with different family"); + return false; + } + + if (r->ip_dest.family && r->ip_dest.family != r->family) + { + warn_elem(e, "uses destination ip with different family"); + return false; + } + + if (r->ip_snat.family && r->ip_snat.family != r->family) + { + warn_elem(e, "uses snat ip with different family"); + return false; + } + + return true; +} + +void +fw3_load_snats(struct fw3_state *state, struct uci_package *p) +{ + struct uci_section *s; + struct uci_element *e; + struct fw3_snat *snat; + + INIT_LIST_HEAD(&state->snats); + + uci_foreach_element(&p->sections, e) + { + s = uci_to_section(e); + + if (strcmp(s->type, "nat")) + continue; + + snat = malloc(sizeof(*snat)); + + if (!snat) + continue; + + memset(snat, 0, sizeof(*snat)); + + INIT_LIST_HEAD(&snat->proto); + + snat->enabled = true; + + if (!fw3_parse_options(snat, fw3_snat_opts, s)) + { + warn_elem(e, "skipped due to invalid options"); + fw3_free_snat(snat); + continue; + } + + if (!snat->enabled) + { + fw3_free_snat(snat); + continue; + } + + if (snat->src.invert) + { + warn_elem(e, "must not have an inverted source"); + fw3_free_snat(snat); + continue; + } + else if (snat->src.set && !snat->src.any && + !(snat->_src = fw3_lookup_zone(state, snat->src.name))) + { + warn_elem(e, "refers to not existing zone '%s'", snat->src.name); + fw3_free_snat(snat); + continue; + } + else if (snat->ipset.set && state->disable_ipsets) + { + warn_elem(e, "skipped due to disabled ipset support"); + fw3_free_snat(snat); + continue; + } + else if (snat->ipset.set && + !(snat->ipset.ptr = fw3_lookup_ipset(state, snat->ipset.name))) + { + warn_elem(e, "refers to unknown ipset '%s'", snat->ipset.name); + fw3_free_snat(snat); + continue; + } + + if (!check_families(e, snat)) + { + fw3_free_snat(snat); + continue; + } + + if (snat->target == FW3_FLAG_UNSPEC) + { + warn_elem(e, "has no target specified, defaulting to MASQUERADE"); + snat->target = FW3_FLAG_MASQUERADE; + } + else if (snat->target < FW3_FLAG_SNAT || snat->target > FW3_FLAG_MASQUERADE) + { + warn_elem(e, "has invalid target specified, defaulting to MASQUERADE"); + snat->target = FW3_FLAG_MASQUERADE; + } + + if (snat->target == FW3_FLAG_SNAT && + !snat->ip_snat.set && !snat->port_snat.set) + { + warn_elem(e, "needs either 'snat_ip' or 'snat_port' for SNAT"); + fw3_free_snat(snat); + continue; + } + else if (snat->target == FW3_FLAG_MASQUERADE && snat->ip_snat.set) + { + warn_elem(e, "must not use 'snat_ip' for MASQUERADE"); + fw3_free_snat(snat); + continue; + } + else if (snat->target == FW3_FLAG_MASQUERADE && snat->port_snat.set) + { + warn_elem(e, "must not use 'snat_port' for MASQUERADE"); + fw3_free_snat(snat); + continue; + } + + if (list_empty(&snat->proto)) + { + warn_elem(e, "does not specify a protocol, assuming all"); + fw3_parse_protocol(&snat->proto, "all", true); + } + + if (snat->_src) + { + set(snat->_src->flags, FW3_FAMILY_V4, FW3_FLAG_SNAT); + snat->_src->conntrack = true; + } + + list_add_tail(&snat->list, &state->snats); + } +} + +static void +append_chain(struct fw3_ipt_rule *r, struct fw3_snat *snat) +{ + if (snat->_src) + fw3_ipt_rule_append(r, "zone_%s_postrouting", snat->src.name); + else + fw3_ipt_rule_append(r, "delegate_postrouting"); +} + +static void +set_target(struct fw3_ipt_rule *r, struct fw3_snat *snat, + struct fw3_protocol *proto) +{ + char buf[sizeof("255.255.255.255:65535-65535\0")]; + + if (snat->target == FW3_FLAG_SNAT) + { + buf[0] = '\0'; + + if (snat->ip_snat.set) + { + inet_ntop(AF_INET, &snat->ip_snat.address.v4, buf, sizeof(buf)); + } + + if (snat->port_snat.set && proto && !proto->any && + (proto->protocol == 6 || proto->protocol == 17)) + { + if (snat->port_snat.port_min == snat->port_snat.port_max) + sprintf(buf + strlen(buf), ":%u", snat->port_snat.port_min); + else + sprintf(buf + strlen(buf), ":%u-%u", + snat->port_snat.port_min, snat->port_snat.port_max); + } + + fw3_ipt_rule_target(r, "SNAT"); + fw3_ipt_rule_addarg(r, false, "--to-source", buf); + } + else + { + fw3_ipt_rule_target(r, "MASQUERADE"); + } +} + +static void +set_comment(struct fw3_ipt_rule *r, const char *name, int num) +{ + if (name) + fw3_ipt_rule_comment(r, name); + else + fw3_ipt_rule_comment(r, "@nat[%u]", num); +} + +static void +print_snat(struct fw3_ipt_handle *h, struct fw3_state *state, + struct fw3_snat *snat, int num, struct fw3_protocol *proto) +{ + struct fw3_ipt_rule *r; + struct fw3_address *src, *dst; + struct fw3_port *spt, *dpt; + + switch (h->table) + { + case FW3_TABLE_NAT: + src = &snat->ip_src; + dst = &snat->ip_dest; + spt = &snat->port_src; + dpt = &snat->port_dest; + + r = fw3_ipt_rule_create(h, proto, NULL, NULL, src, dst); + fw3_ipt_rule_sport_dport(r, spt, dpt); + fw3_ipt_rule_ipset(r, &snat->ipset); + fw3_ipt_rule_limit(r, &snat->limit); + fw3_ipt_rule_time(r, &snat->time); + fw3_ipt_rule_mark(r, &snat->mark); + set_target(r, snat, proto); + fw3_ipt_rule_extra(r, snat->extra); + set_comment(r, snat->name, num); + append_chain(r, snat); + break; + + default: + break; + } +} + +static void +expand_snat(struct fw3_ipt_handle *handle, struct fw3_state *state, + struct fw3_snat *snat, int num) +{ + struct fw3_protocol *proto; + + if (snat->name) + info(" * NAT '%s'", snat->name); + else + info(" * NAT #%u", num); + + if (!fw3_is_family(snat->_src, handle->family)) + { + info(" ! Skipping due to different family of zone"); + return; + } + + if (!fw3_is_family(&snat->ip_src, handle->family) || + !fw3_is_family(&snat->ip_dest, handle->family) || + !fw3_is_family(&snat->ip_snat, handle->family)) + { + if (!snat->ip_src.resolved || + !snat->ip_dest.resolved || + !snat->ip_snat.resolved) + info(" ! Skipping due to different family of ip address"); + + return; + } + + if (snat->ipset.ptr) + { + if (!fw3_is_family(snat->ipset.ptr, handle->family)) + { + info(" ! Skipping due to different family in ipset"); + return; + } + + if (!fw3_check_ipset(snat->ipset.ptr)) + { + info(" ! Skipping due to missing ipset '%s'", + snat->ipset.ptr->external ? + snat->ipset.ptr->external : snat->ipset.ptr->name); + return; + } + + set(snat->ipset.ptr->flags, handle->family, handle->family); + } + + fw3_foreach(proto, &snat->proto) + print_snat(handle, state, snat, num, proto); +} + +void +fw3_print_snats(struct fw3_ipt_handle *handle, struct fw3_state *state) +{ + int num = 0; + struct fw3_snat *snat; + + if (handle->family == FW3_FAMILY_V6) + return; + + if (handle->table != FW3_TABLE_NAT) + return; + + list_for_each_entry(snat, &state->snats, list) + expand_snat(handle, state, snat, num++); +} diff --git a/snats.h b/snats.h new file mode 100644 index 0000000..00d1406 --- /dev/null +++ b/snats.h @@ -0,0 +1,36 @@ +/* + * firewall3 - 3rd OpenWrt UCI firewall implementation + * + * Copyright (C) 2014 Jo-Philipp Wich + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef __FW3_SNATS_H +#define __FW3_SNATS_H + +#include "options.h" +#include "zones.h" +#include "ipsets.h" +#include "ubus.h" +#include "iptables.h" + +extern const struct fw3_option fw3_snat_opts[]; + +void fw3_load_snats(struct fw3_state *state, struct uci_package *p); +void fw3_print_snats(struct fw3_ipt_handle *handle, struct fw3_state *state); + +#define fw3_free_snat(redir) \ + fw3_free_object(redir, fw3_snat_opts) + +#endif -- 2.25.1