| /* |
| * (C) 2012-2014 by Pablo Neira Ayuso <pablo@netfilter.org> |
| * (C) 2013 by Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This code has been sponsored by Sophos Astaro <http://www.sophos.com> |
| */ |
| |
| #include <string.h> |
| #include <stdio.h> |
| |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <netinet/ip.h> |
| #include <netdb.h> |
| |
| #include <xtables.h> |
| |
| #include <linux/netfilter/nf_tables.h> |
| |
| #include "nft.h" |
| #include "nft-shared.h" |
| |
| static int nft_ipv4_add(struct nft_handle *h, struct nftnl_rule *r, void *data) |
| { |
| struct iptables_command_state *cs = data; |
| struct xtables_rule_match *matchp; |
| uint32_t op; |
| int ret; |
| |
| if (cs->fw.ip.iniface[0] != '\0') { |
| op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_VIA_IN); |
| add_iniface(r, cs->fw.ip.iniface, op); |
| } |
| |
| if (cs->fw.ip.outiface[0] != '\0') { |
| op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_VIA_OUT); |
| add_outiface(r, cs->fw.ip.outiface, op); |
| } |
| |
| if (cs->fw.ip.proto != 0) { |
| op = nft_invflags2cmp(cs->fw.ip.invflags, XT_INV_PROTO); |
| add_l4proto(r, cs->fw.ip.proto, op); |
| } |
| |
| if (cs->fw.ip.src.s_addr || cs->fw.ip.smsk.s_addr || cs->fw.ip.invflags & IPT_INV_SRCIP) { |
| op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_SRCIP); |
| add_addr(r, NFT_PAYLOAD_NETWORK_HEADER, |
| offsetof(struct iphdr, saddr), |
| &cs->fw.ip.src.s_addr, &cs->fw.ip.smsk.s_addr, |
| sizeof(struct in_addr), op); |
| } |
| if (cs->fw.ip.dst.s_addr || cs->fw.ip.dmsk.s_addr || cs->fw.ip.invflags & IPT_INV_DSTIP) { |
| op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_DSTIP); |
| add_addr(r, NFT_PAYLOAD_NETWORK_HEADER, |
| offsetof(struct iphdr, daddr), |
| &cs->fw.ip.dst.s_addr, &cs->fw.ip.dmsk.s_addr, |
| sizeof(struct in_addr), op); |
| } |
| if (cs->fw.ip.flags & IPT_F_FRAG) { |
| add_payload(r, offsetof(struct iphdr, frag_off), 2, |
| NFT_PAYLOAD_NETWORK_HEADER); |
| /* get the 13 bits that contain the fragment offset */ |
| add_bitwise_u16(r, htons(0x1fff), 0); |
| |
| /* if offset is non-zero, this is a fragment */ |
| op = NFT_CMP_NEQ; |
| if (cs->fw.ip.invflags & IPT_INV_FRAG) |
| op = NFT_CMP_EQ; |
| |
| add_cmp_u16(r, 0, op); |
| } |
| |
| add_compat(r, cs->fw.ip.proto, cs->fw.ip.invflags & XT_INV_PROTO); |
| |
| for (matchp = cs->matches; matchp; matchp = matchp->next) { |
| ret = add_match(h, r, matchp->match->m); |
| if (ret < 0) |
| return ret; |
| } |
| |
| /* Counters need to me added before the target, otherwise they are |
| * increased for each rule because of the way nf_tables works. |
| */ |
| if (add_counters(r, cs->counters.pcnt, cs->counters.bcnt) < 0) |
| return -1; |
| |
| return add_action(r, cs, !!(cs->fw.ip.flags & IPT_F_GOTO)); |
| } |
| |
| static bool nft_ipv4_is_same(const void *data_a, |
| const void *data_b) |
| { |
| const struct iptables_command_state *a = data_a; |
| const struct iptables_command_state *b = data_b; |
| |
| if (a->fw.ip.src.s_addr != b->fw.ip.src.s_addr |
| || a->fw.ip.dst.s_addr != b->fw.ip.dst.s_addr |
| || a->fw.ip.smsk.s_addr != b->fw.ip.smsk.s_addr |
| || a->fw.ip.dmsk.s_addr != b->fw.ip.dmsk.s_addr |
| || a->fw.ip.proto != b->fw.ip.proto |
| || a->fw.ip.flags != b->fw.ip.flags |
| || a->fw.ip.invflags != b->fw.ip.invflags) { |
| DEBUGP("different src/dst/proto/flags/invflags\n"); |
| return false; |
| } |
| |
| return is_same_interfaces(a->fw.ip.iniface, a->fw.ip.outiface, |
| a->fw.ip.iniface_mask, a->fw.ip.outiface_mask, |
| b->fw.ip.iniface, b->fw.ip.outiface, |
| b->fw.ip.iniface_mask, b->fw.ip.outiface_mask); |
| } |
| |
| static void get_frag(struct nft_xt_ctx *ctx, struct nftnl_expr *e, bool *inv) |
| { |
| uint8_t op; |
| |
| /* we assume correct mask and xor */ |
| if (!(ctx->flags & NFT_XT_CTX_BITWISE)) |
| return; |
| |
| /* we assume correct data */ |
| op = nftnl_expr_get_u32(e, NFTNL_EXPR_CMP_OP); |
| if (op == NFT_CMP_EQ) |
| *inv = true; |
| else |
| *inv = false; |
| |
| ctx->flags &= ~NFT_XT_CTX_BITWISE; |
| } |
| |
| static const char *mask_to_str(uint32_t mask) |
| { |
| static char mask_str[sizeof("255.255.255.255")]; |
| uint32_t bits, hmask = ntohl(mask); |
| struct in_addr mask_addr = { |
| .s_addr = mask, |
| }; |
| int i; |
| |
| if (mask == 0xFFFFFFFFU) { |
| sprintf(mask_str, "32"); |
| return mask_str; |
| } |
| |
| i = 32; |
| bits = 0xFFFFFFFEU; |
| while (--i >= 0 && hmask != bits) |
| bits <<= 1; |
| if (i >= 0) |
| sprintf(mask_str, "%u", i); |
| else |
| sprintf(mask_str, "%s", inet_ntoa(mask_addr)); |
| |
| return mask_str; |
| } |
| |
| static void nft_ipv4_parse_meta(struct nft_xt_ctx *ctx, struct nftnl_expr *e, |
| void *data) |
| { |
| struct iptables_command_state *cs = data; |
| |
| switch (ctx->meta.key) { |
| case NFT_META_L4PROTO: |
| cs->fw.ip.proto = nftnl_expr_get_u8(e, NFTNL_EXPR_CMP_DATA); |
| if (nftnl_expr_get_u32(e, NFTNL_EXPR_CMP_OP) == NFT_CMP_NEQ) |
| cs->fw.ip.invflags |= XT_INV_PROTO; |
| return; |
| default: |
| break; |
| } |
| |
| parse_meta(e, ctx->meta.key, cs->fw.ip.iniface, cs->fw.ip.iniface_mask, |
| cs->fw.ip.outiface, cs->fw.ip.outiface_mask, |
| &cs->fw.ip.invflags); |
| } |
| |
| static void parse_mask_ipv4(struct nft_xt_ctx *ctx, struct in_addr *mask) |
| { |
| mask->s_addr = ctx->bitwise.mask[0]; |
| } |
| |
| static void nft_ipv4_parse_payload(struct nft_xt_ctx *ctx, |
| struct nftnl_expr *e, void *data) |
| { |
| struct iptables_command_state *cs = data; |
| struct in_addr addr; |
| uint8_t proto; |
| bool inv; |
| |
| switch(ctx->payload.offset) { |
| case offsetof(struct iphdr, saddr): |
| get_cmp_data(e, &addr, sizeof(addr), &inv); |
| cs->fw.ip.src.s_addr = addr.s_addr; |
| if (ctx->flags & NFT_XT_CTX_BITWISE) { |
| parse_mask_ipv4(ctx, &cs->fw.ip.smsk); |
| ctx->flags &= ~NFT_XT_CTX_BITWISE; |
| } else { |
| memset(&cs->fw.ip.smsk, 0xff, |
| min(ctx->payload.len, sizeof(struct in_addr))); |
| } |
| |
| if (inv) |
| cs->fw.ip.invflags |= IPT_INV_SRCIP; |
| break; |
| case offsetof(struct iphdr, daddr): |
| get_cmp_data(e, &addr, sizeof(addr), &inv); |
| cs->fw.ip.dst.s_addr = addr.s_addr; |
| if (ctx->flags & NFT_XT_CTX_BITWISE) { |
| parse_mask_ipv4(ctx, &cs->fw.ip.dmsk); |
| ctx->flags &= ~NFT_XT_CTX_BITWISE; |
| } else { |
| memset(&cs->fw.ip.dmsk, 0xff, |
| min(ctx->payload.len, sizeof(struct in_addr))); |
| } |
| |
| if (inv) |
| cs->fw.ip.invflags |= IPT_INV_DSTIP; |
| break; |
| case offsetof(struct iphdr, protocol): |
| get_cmp_data(e, &proto, sizeof(proto), &inv); |
| cs->fw.ip.proto = proto; |
| if (inv) |
| cs->fw.ip.invflags |= IPT_INV_PROTO; |
| break; |
| case offsetof(struct iphdr, frag_off): |
| cs->fw.ip.flags |= IPT_F_FRAG; |
| inv = false; |
| get_frag(ctx, e, &inv); |
| if (inv) |
| cs->fw.ip.invflags |= IPT_INV_FRAG; |
| break; |
| default: |
| DEBUGP("unknown payload offset %d\n", ctx->payload.offset); |
| break; |
| } |
| } |
| |
| static void nft_ipv4_parse_immediate(const char *jumpto, bool nft_goto, |
| void *data) |
| { |
| struct iptables_command_state *cs = data; |
| |
| cs->jumpto = jumpto; |
| |
| if (nft_goto) |
| cs->fw.ip.flags |= IPT_F_GOTO; |
| } |
| |
| static void print_fragment(unsigned int flags, unsigned int invflags, |
| unsigned int format) |
| { |
| if (!(format & FMT_OPTIONS)) |
| return; |
| |
| if (format & FMT_NOTABLE) |
| fputs("opt ", stdout); |
| fputc(invflags & IPT_INV_FRAG ? '!' : '-', stdout); |
| fputc(flags & IPT_F_FRAG ? 'f' : '-', stdout); |
| fputc(' ', stdout); |
| } |
| |
| static void nft_ipv4_print_rule(struct nft_handle *h, struct nftnl_rule *r, |
| unsigned int num, unsigned int format) |
| { |
| struct iptables_command_state cs = {}; |
| |
| nft_rule_to_iptables_command_state(h, r, &cs); |
| |
| print_rule_details(&cs, cs.jumpto, cs.fw.ip.flags, |
| cs.fw.ip.invflags, cs.fw.ip.proto, num, format); |
| print_fragment(cs.fw.ip.flags, cs.fw.ip.invflags, format); |
| print_ifaces(cs.fw.ip.iniface, cs.fw.ip.outiface, cs.fw.ip.invflags, |
| format); |
| print_ipv4_addresses(&cs.fw, format); |
| |
| if (format & FMT_NOTABLE) |
| fputs(" ", stdout); |
| |
| #ifdef IPT_F_GOTO |
| if (cs.fw.ip.flags & IPT_F_GOTO) |
| printf("[goto] "); |
| #endif |
| |
| print_matches_and_target(&cs, format); |
| |
| if (!(format & FMT_NONEWLINE)) |
| fputc('\n', stdout); |
| |
| nft_clear_iptables_command_state(&cs); |
| } |
| |
| static void save_ipv4_addr(char letter, const struct in_addr *addr, |
| uint32_t mask, int invert) |
| { |
| if (!mask && !invert && !addr->s_addr) |
| return; |
| |
| printf("%s-%c %s/%s ", invert ? "! " : "", letter, inet_ntoa(*addr), |
| mask_to_str(mask)); |
| } |
| |
| static void nft_ipv4_save_rule(const void *data, unsigned int format) |
| { |
| const struct iptables_command_state *cs = data; |
| |
| save_ipv4_addr('s', &cs->fw.ip.src, cs->fw.ip.smsk.s_addr, |
| cs->fw.ip.invflags & IPT_INV_SRCIP); |
| save_ipv4_addr('d', &cs->fw.ip.dst, cs->fw.ip.dmsk.s_addr, |
| cs->fw.ip.invflags & IPT_INV_DSTIP); |
| |
| save_rule_details(cs, cs->fw.ip.invflags, cs->fw.ip.proto, |
| cs->fw.ip.iniface, cs->fw.ip.iniface_mask, |
| cs->fw.ip.outiface, cs->fw.ip.outiface_mask); |
| |
| if (cs->fw.ip.flags & IPT_F_FRAG) { |
| if (cs->fw.ip.invflags & IPT_INV_FRAG) |
| printf("! "); |
| printf("-f "); |
| } |
| |
| save_matches_and_target(cs, cs->fw.ip.flags & IPT_F_GOTO, |
| &cs->fw, format); |
| } |
| |
| static void nft_ipv4_proto_parse(struct iptables_command_state *cs, |
| struct xtables_args *args) |
| { |
| cs->fw.ip.proto = args->proto; |
| cs->fw.ip.invflags = args->invflags; |
| } |
| |
| static void nft_ipv4_post_parse(int command, |
| struct iptables_command_state *cs, |
| struct xtables_args *args) |
| { |
| cs->fw.ip.flags = args->flags; |
| /* We already set invflags in proto_parse, but we need to refresh it |
| * to include new parsed options. |
| */ |
| cs->fw.ip.invflags = args->invflags; |
| |
| strncpy(cs->fw.ip.iniface, args->iniface, IFNAMSIZ); |
| memcpy(cs->fw.ip.iniface_mask, |
| args->iniface_mask, IFNAMSIZ*sizeof(unsigned char)); |
| |
| strncpy(cs->fw.ip.outiface, args->outiface, IFNAMSIZ); |
| memcpy(cs->fw.ip.outiface_mask, |
| args->outiface_mask, IFNAMSIZ*sizeof(unsigned char)); |
| |
| if (args->goto_set) |
| cs->fw.ip.flags |= IPT_F_GOTO; |
| |
| cs->counters.pcnt = args->pcnt_cnt; |
| cs->counters.bcnt = args->bcnt_cnt; |
| |
| if (command & (CMD_REPLACE | CMD_INSERT | |
| CMD_DELETE | CMD_APPEND | CMD_CHECK)) { |
| if (!(cs->options & OPT_DESTINATION)) |
| args->dhostnetworkmask = "0.0.0.0/0"; |
| if (!(cs->options & OPT_SOURCE)) |
| args->shostnetworkmask = "0.0.0.0/0"; |
| } |
| |
| if (args->shostnetworkmask) |
| xtables_ipparse_multiple(args->shostnetworkmask, |
| &args->s.addr.v4, &args->s.mask.v4, |
| &args->s.naddrs); |
| if (args->dhostnetworkmask) |
| xtables_ipparse_multiple(args->dhostnetworkmask, |
| &args->d.addr.v4, &args->d.mask.v4, |
| &args->d.naddrs); |
| |
| if ((args->s.naddrs > 1 || args->d.naddrs > 1) && |
| (cs->fw.ip.invflags & (IPT_INV_SRCIP | IPT_INV_DSTIP))) |
| xtables_error(PARAMETER_PROBLEM, |
| "! not allowed with multiple" |
| " source or destination IP addresses"); |
| } |
| |
| static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl) |
| { |
| const struct iptables_command_state *cs = data; |
| const char *comment; |
| int ret; |
| |
| xlate_ifname(xl, "iifname", cs->fw.ip.iniface, |
| cs->fw.ip.invflags & IPT_INV_VIA_IN); |
| xlate_ifname(xl, "oifname", cs->fw.ip.outiface, |
| cs->fw.ip.invflags & IPT_INV_VIA_OUT); |
| |
| if (cs->fw.ip.flags & IPT_F_FRAG) { |
| xt_xlate_add(xl, "ip frag-off & 0x1fff %s%x ", |
| cs->fw.ip.invflags & IPT_INV_FRAG? "" : "!= ", 0); |
| } |
| |
| if (cs->fw.ip.proto != 0) { |
| const struct protoent *pent = |
| getprotobynumber(cs->fw.ip.proto); |
| char protonum[sizeof("65535")]; |
| const char *name = protonum; |
| |
| snprintf(protonum, sizeof(protonum), "%u", |
| cs->fw.ip.proto); |
| |
| if (!pent || !xlate_find_match(cs, pent->p_name)) { |
| if (pent) |
| name = pent->p_name; |
| xt_xlate_add(xl, "ip protocol %s%s ", |
| cs->fw.ip.invflags & IPT_INV_PROTO ? |
| "!= " : "", name); |
| } |
| } |
| |
| if (cs->fw.ip.src.s_addr != 0) { |
| xt_xlate_add(xl, "ip saddr %s%s%s ", |
| cs->fw.ip.invflags & IPT_INV_SRCIP ? "!= " : "", |
| inet_ntoa(cs->fw.ip.src), |
| xtables_ipmask_to_numeric(&cs->fw.ip.smsk)); |
| } |
| if (cs->fw.ip.dst.s_addr != 0) { |
| xt_xlate_add(xl, "ip daddr %s%s%s ", |
| cs->fw.ip.invflags & IPT_INV_DSTIP ? "!= " : "", |
| inet_ntoa(cs->fw.ip.dst), |
| xtables_ipmask_to_numeric(&cs->fw.ip.dmsk)); |
| } |
| |
| ret = xlate_matches(cs, xl); |
| if (!ret) |
| return ret; |
| |
| /* Always add counters per rule, as in iptables */ |
| xt_xlate_add(xl, "counter"); |
| ret = xlate_action(cs, !!(cs->fw.ip.flags & IPT_F_GOTO), xl); |
| |
| comment = xt_xlate_get_comment(xl); |
| if (comment) |
| xt_xlate_add(xl, " comment %s", comment); |
| |
| return ret; |
| } |
| |
| struct nft_family_ops nft_family_ops_ipv4 = { |
| .add = nft_ipv4_add, |
| .is_same = nft_ipv4_is_same, |
| .parse_meta = nft_ipv4_parse_meta, |
| .parse_payload = nft_ipv4_parse_payload, |
| .parse_immediate = nft_ipv4_parse_immediate, |
| .print_header = print_header, |
| .print_rule = nft_ipv4_print_rule, |
| .save_rule = nft_ipv4_save_rule, |
| .save_chain = nft_ipv46_save_chain, |
| .proto_parse = nft_ipv4_proto_parse, |
| .post_parse = nft_ipv4_post_parse, |
| .parse_target = nft_ipv46_parse_target, |
| .rule_to_cs = nft_rule_to_iptables_command_state, |
| .clear_cs = nft_clear_iptables_command_state, |
| .xlate = nft_ipv4_xlate, |
| }; |