/* * iprule.c "ip rule". * * 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. * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> * */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <syslog.h> #include <fcntl.h> #include <sys/socket.h> #include <netinet/in.h> #include <netinet/ip.h> #include <arpa/inet.h> #include <string.h> #include <linux/if.h> #include <linux/fib_rules.h> #include <errno.h> #include "rt_names.h" #include "utils.h" #include "ip_common.h" enum list_action { IPRULE_LIST, IPRULE_FLUSH, IPRULE_SAVE, }; extern struct rtnl_handle rth; static void usage(void) __attribute__((noreturn)); static void usage(void) { fprintf(stderr, "Usage: ip rule { add | del } SELECTOR ACTION\n" " ip rule { flush | save | restore }\n" " ip rule [ list [ SELECTOR ]]\n" "SELECTOR := [ not ] [ from PREFIX ] [ to PREFIX ] [ tos TOS ] [ fwmark FWMARK[/MASK] ]\n" " [ iif STRING ] [ oif STRING ] [ pref NUMBER ] [ l3mdev ]\n" " [ uidrange NUMBER-NUMBER ]\n" "ACTION := [ table TABLE_ID ]\n" " [ nat ADDRESS ]\n" " [ realms [SRCREALM/]DSTREALM ]\n" " [ goto NUMBER ]\n" " SUPPRESSOR\n" "SUPPRESSOR := [ suppress_prefixlength NUMBER ]\n" " [ suppress_ifgroup DEVGROUP ]\n" "TABLE_ID := [ local | main | default | NUMBER ]\n"); exit(-1); } static struct { int not; int l3mdev; int iifmask, oifmask, uidrange; unsigned int tb; unsigned int tos, tosmask; unsigned int pref, prefmask; unsigned int fwmark, fwmask; char iif[IFNAMSIZ]; char oif[IFNAMSIZ]; struct fib_rule_uid_range range; inet_prefix src; inet_prefix dst; } filter; static bool filter_nlmsg(struct nlmsghdr *n, struct rtattr **tb, int host_len) { struct rtmsg *r = NLMSG_DATA(n); inet_prefix src = { .family = r->rtm_family }; inet_prefix dst = { .family = r->rtm_family }; __u32 table; if (preferred_family != AF_UNSPEC && r->rtm_family != preferred_family) return false; if (filter.prefmask && filter.pref ^ (tb[FRA_PRIORITY] ? rta_getattr_u32(tb[FRA_PRIORITY]) : 0)) return false; if (filter.not && !(r->rtm_flags & FIB_RULE_INVERT)) return false; if (filter.src.family) { if (tb[FRA_SRC]) { memcpy(&src.data, RTA_DATA(tb[FRA_SRC]), (r->rtm_src_len + 7) / 8); } if (filter.src.family != r->rtm_family || filter.src.bitlen > r->rtm_src_len || inet_addr_match(&src, &filter.src, filter.src.bitlen)) return false; } if (filter.dst.family) { if (tb[FRA_DST]) { memcpy(&dst.data, RTA_DATA(tb[FRA_DST]), (r->rtm_dst_len + 7) / 8); } if (filter.dst.family != r->rtm_family || filter.dst.bitlen > r->rtm_dst_len || inet_addr_match(&dst, &filter.dst, filter.dst.bitlen)) return false; } if (filter.tosmask && filter.tos ^ r->rtm_tos) return false; if (filter.fwmark) { __u32 mark = 0; if (tb[FRA_FWMARK]) mark = rta_getattr_u32(tb[FRA_FWMARK]); if (filter.fwmark ^ mark) return false; } if (filter.fwmask) { __u32 mask = 0; if (tb[FRA_FWMASK]) mask = rta_getattr_u32(tb[FRA_FWMASK]); if (filter.fwmask ^ mask) return false; } if (filter.iifmask) { if (tb[FRA_IFNAME]) { if (strcmp(filter.iif, rta_getattr_str(tb[FRA_IFNAME])) != 0) return false; } else { return false; } } if (filter.oifmask) { if (tb[FRA_OIFNAME]) { if (strcmp(filter.oif, rta_getattr_str(tb[FRA_OIFNAME])) != 0) return false; } else { return false; } } if (filter.l3mdev && !(tb[FRA_L3MDEV] && rta_getattr_u8(tb[FRA_L3MDEV]))) return false; if (filter.uidrange) { struct fib_rule_uid_range *r = RTA_DATA(tb[FRA_UID_RANGE]); if (!tb[FRA_UID_RANGE] || r->start != filter.range.start || r->end != filter.range.end) return false; } table = rtm_get_table(r, tb); if (filter.tb > 0 && filter.tb ^ table) return false; return true; } int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg) { FILE *fp = (FILE *)arg; struct rtmsg *r = NLMSG_DATA(n); int len = n->nlmsg_len; int host_len = -1; __u32 table; struct rtattr *tb[FRA_MAX+1]; SPRINT_BUF(b1); if (n->nlmsg_type != RTM_NEWRULE && n->nlmsg_type != RTM_DELRULE) return 0; len -= NLMSG_LENGTH(sizeof(*r)); if (len < 0) return -1; parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len); host_len = af_bit_len(r->rtm_family); if (!filter_nlmsg(n, tb, host_len)) return 0; if (n->nlmsg_type == RTM_DELRULE) fprintf(fp, "Deleted "); if (tb[FRA_PRIORITY]) fprintf(fp, "%u:\t", rta_getattr_u32(tb[FRA_PRIORITY])); else fprintf(fp, "0:\t"); if (r->rtm_flags & FIB_RULE_INVERT) fprintf(fp, "not "); if (tb[FRA_SRC]) { if (r->rtm_src_len != host_len) { fprintf(fp, "from %s/%u ", rt_addr_n2a_rta(r->rtm_family, tb[FRA_SRC]), r->rtm_src_len); } else { fprintf(fp, "from %s ", format_host_rta(r->rtm_family, tb[FRA_SRC])); } } else if (r->rtm_src_len) { fprintf(fp, "from 0/%d ", r->rtm_src_len); } else { fprintf(fp, "from all "); } if (tb[FRA_DST]) { if (r->rtm_dst_len != host_len) { fprintf(fp, "to %s/%u ", rt_addr_n2a_rta(r->rtm_family, tb[FRA_DST]), r->rtm_dst_len); } else { fprintf(fp, "to %s ", format_host_rta(r->rtm_family, tb[FRA_DST])); } } else if (r->rtm_dst_len) { fprintf(fp, "to 0/%d ", r->rtm_dst_len); } if (r->rtm_tos) { SPRINT_BUF(b1); fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1))); } if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) { __u32 mark = 0, mask = 0; if (tb[FRA_FWMARK]) mark = rta_getattr_u32(tb[FRA_FWMARK]); if (tb[FRA_FWMASK] && (mask = rta_getattr_u32(tb[FRA_FWMASK])) != 0xFFFFFFFF) fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask); else fprintf(fp, "fwmark 0x%x ", mark); } if (tb[FRA_IFNAME]) { fprintf(fp, "iif %s ", rta_getattr_str(tb[FRA_IFNAME])); if (r->rtm_flags & FIB_RULE_IIF_DETACHED) fprintf(fp, "[detached] "); } if (tb[FRA_OIFNAME]) { fprintf(fp, "oif %s ", rta_getattr_str(tb[FRA_OIFNAME])); if (r->rtm_flags & FIB_RULE_OIF_DETACHED) fprintf(fp, "[detached] "); } if (tb[FRA_L3MDEV]) { if (rta_getattr_u8(tb[FRA_L3MDEV])) fprintf(fp, "lookup [l3mdev-table] "); } if (tb[FRA_UID_RANGE]) { struct fib_rule_uid_range *r = RTA_DATA(tb[FRA_UID_RANGE]); fprintf(fp, "uidrange %u-%u ", r->start, r->end); } table = rtm_get_table(r, tb); if (table) { fprintf(fp, "lookup %s ", rtnl_rttable_n2a(table, b1, sizeof(b1))); if (tb[FRA_SUPPRESS_PREFIXLEN]) { int pl = rta_getattr_u32(tb[FRA_SUPPRESS_PREFIXLEN]); if (pl != -1) fprintf(fp, "suppress_prefixlength %d ", pl); } if (tb[FRA_SUPPRESS_IFGROUP]) { int group = rta_getattr_u32(tb[FRA_SUPPRESS_IFGROUP]); if (group != -1) { SPRINT_BUF(b1); fprintf(fp, "suppress_ifgroup %s ", rtnl_group_n2a(group, b1, sizeof(b1))); } } } if (tb[FRA_FLOW]) { __u32 to = rta_getattr_u32(tb[FRA_FLOW]); __u32 from = to>>16; to &= 0xFFFF; if (from) { fprintf(fp, "realms %s/", rtnl_rtrealm_n2a(from, b1, sizeof(b1))); } fprintf(fp, "%s ", rtnl_rtrealm_n2a(to, b1, sizeof(b1))); } if (r->rtm_type == RTN_NAT) { if (tb[RTA_GATEWAY]) { fprintf(fp, "map-to %s ", format_host_rta(r->rtm_family, tb[RTA_GATEWAY])); } else fprintf(fp, "masquerade"); } else if (r->rtm_type == FR_ACT_GOTO) { fprintf(fp, "goto "); if (tb[FRA_GOTO]) fprintf(fp, "%u", rta_getattr_u32(tb[FRA_GOTO])); else fprintf(fp, "none"); if (r->rtm_flags & FIB_RULE_UNRESOLVED) fprintf(fp, " [unresolved]"); } else if (r->rtm_type == FR_ACT_NOP) fprintf(fp, "nop"); else if (r->rtm_type != RTN_UNICAST) fprintf(fp, "%s", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1))); fprintf(fp, "\n"); fflush(fp); return 0; } static __u32 rule_dump_magic = 0x71706986; static int save_rule_prep(void) { int ret; if (isatty(STDOUT_FILENO)) { fprintf(stderr, "Not sending a binary stream to stdout\n"); return -1; } ret = write(STDOUT_FILENO, &rule_dump_magic, sizeof(rule_dump_magic)); if (ret != sizeof(rule_dump_magic)) { fprintf(stderr, "Can't write magic to dump file\n"); return -1; } return 0; } static int save_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg) { int ret; ret = write(STDOUT_FILENO, n, n->nlmsg_len); if ((ret > 0) && (ret != n->nlmsg_len)) { fprintf(stderr, "Short write while saving nlmsg\n"); ret = -EIO; } return ret == n->nlmsg_len ? 0 : ret; } static int flush_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg) { struct rtnl_handle rth2; struct rtmsg *r = NLMSG_DATA(n); int len = n->nlmsg_len; struct rtattr *tb[FRA_MAX+1]; len -= NLMSG_LENGTH(sizeof(*r)); if (len < 0) return -1; parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len); if (tb[FRA_PRIORITY]) { n->nlmsg_type = RTM_DELRULE; n->nlmsg_flags = NLM_F_REQUEST; if (rtnl_open(&rth2, 0) < 0) return -1; if (rtnl_talk(&rth2, n, NULL, 0) < 0) return -2; rtnl_close(&rth2); } return 0; } static int iprule_list_flush_or_save(int argc, char **argv, int action) { rtnl_filter_t filter_fn; int af = preferred_family; if (af == AF_UNSPEC) af = AF_INET; if (action != IPRULE_LIST && argc > 0) { fprintf(stderr, "\"ip rule %s\" does not take any arguments.\n", action == IPRULE_SAVE ? "save" : "flush"); return -1; } switch (action) { case IPRULE_SAVE: if (save_rule_prep()) return -1; filter_fn = save_rule; break; case IPRULE_FLUSH: filter_fn = flush_rule; break; default: filter_fn = print_rule; } memset(&filter, 0, sizeof(filter)); while (argc > 0) { if (matches(*argv, "preference") == 0 || matches(*argv, "order") == 0 || matches(*argv, "priority") == 0) { __u32 pref; NEXT_ARG(); if (get_u32(&pref, *argv, 0)) invarg("preference value is invalid\n", *argv); filter.pref = pref; filter.prefmask = 1; } else if (strcmp(*argv, "not") == 0) { filter.not = 1; } else if (strcmp(*argv, "tos") == 0) { __u32 tos; NEXT_ARG(); if (rtnl_dsfield_a2n(&tos, *argv)) invarg("TOS value is invalid\n", *argv); filter.tos = tos; filter.tosmask = 1; } else if (strcmp(*argv, "fwmark") == 0) { char *slash; __u32 fwmark, fwmask; NEXT_ARG(); slash = strchr(*argv, '/'); if (slash != NULL) *slash = '\0'; if (get_u32(&fwmark, *argv, 0)) invarg("fwmark value is invalid\n", *argv); filter.fwmark = fwmark; if (slash) { if (get_u32(&fwmask, slash+1, 0)) invarg("fwmask value is invalid\n", slash+1); filter.fwmask = fwmask; } } else if (strcmp(*argv, "dev") == 0 || strcmp(*argv, "iif") == 0) { NEXT_ARG(); if (get_ifname(filter.iif, *argv)) invarg("\"iif\"/\"dev\" not a valid ifname", *argv); filter.iifmask = 1; } else if (strcmp(*argv, "oif") == 0) { NEXT_ARG(); if (get_ifname(filter.oif, *argv)) invarg("\"oif\" not a valid ifname", *argv); filter.oifmask = 1; } else if (strcmp(*argv, "l3mdev") == 0) { filter.l3mdev = 1; } else if (strcmp(*argv, "uidrange") == 0) { NEXT_ARG(); filter.uidrange = 1; if (sscanf(*argv, "%u-%u", &filter.range.start, &filter.range.end) != 2) invarg("invalid UID range\n", *argv); } else if (matches(*argv, "lookup") == 0 || matches(*argv, "table") == 0) { __u32 tid; NEXT_ARG(); if (rtnl_rttable_a2n(&tid, *argv)) invarg("table id value is invalid\n", *argv); filter.tb = tid; } else if (matches(*argv, "from") == 0 || matches(*argv, "src") == 0) { NEXT_ARG(); get_prefix(&filter.src, *argv, af); } else { if (matches(*argv, "dst") == 0 || matches(*argv, "to") == 0) { NEXT_ARG(); } get_prefix(&filter.dst, *argv, af); } argc--; argv++; } if (rtnl_wilddump_request(&rth, af, RTM_GETRULE) < 0) { perror("Cannot send dump request"); return 1; } if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) { fprintf(stderr, "Dump terminated\n"); return 1; } return 0; } static int rule_dump_check_magic(void) { int ret; __u32 magic = 0; if (isatty(STDIN_FILENO)) { fprintf(stderr, "Can't restore rule dump from a terminal\n"); return -1; } ret = fread(&magic, sizeof(magic), 1, stdin); if (magic != rule_dump_magic) { fprintf(stderr, "Magic mismatch (%d elems, %x magic)\n", ret, magic); return -1; } return 0; } static int restore_handler(const struct sockaddr_nl *nl, struct rtnl_ctrl_data *ctrl, struct nlmsghdr *n, void *arg) { int ret; n->nlmsg_flags |= NLM_F_REQUEST | NLM_F_CREATE | NLM_F_ACK; ll_init_map(&rth); ret = rtnl_talk(&rth, n, n, sizeof(*n)); if ((ret < 0) && (errno == EEXIST)) ret = 0; return ret; } static int iprule_restore(void) { if (rule_dump_check_magic()) exit(-1); exit(rtnl_from_file(stdin, &restore_handler, NULL)); } static int iprule_modify(int cmd, int argc, char **argv) { int l3mdev_rule = 0; int table_ok = 0; __u32 tid = 0; struct { struct nlmsghdr n; struct rtmsg r; char buf[1024]; } req = { .n.nlmsg_type = cmd, .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)), .n.nlmsg_flags = NLM_F_REQUEST, .r.rtm_family = preferred_family, .r.rtm_protocol = RTPROT_BOOT, .r.rtm_scope = RT_SCOPE_UNIVERSE, .r.rtm_type = RTN_UNSPEC, }; if (cmd == RTM_NEWRULE) { req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL; req.r.rtm_type = RTN_UNICAST; } if (cmd == RTM_DELRULE && argc == 0) { fprintf(stderr, "\"ip rule del\" requires arguments.\n"); return -1; } while (argc > 0) { if (strcmp(*argv, "not") == 0) { req.r.rtm_flags |= FIB_RULE_INVERT; } else if (strcmp(*argv, "from") == 0) { inet_prefix dst; NEXT_ARG(); get_prefix(&dst, *argv, req.r.rtm_family); req.r.rtm_src_len = dst.bitlen; addattr_l(&req.n, sizeof(req), FRA_SRC, &dst.data, dst.bytelen); } else if (strcmp(*argv, "to") == 0) { inet_prefix dst; NEXT_ARG(); get_prefix(&dst, *argv, req.r.rtm_family); req.r.rtm_dst_len = dst.bitlen; addattr_l(&req.n, sizeof(req), FRA_DST, &dst.data, dst.bytelen); } else if (matches(*argv, "preference") == 0 || matches(*argv, "order") == 0 || matches(*argv, "priority") == 0) { __u32 pref; NEXT_ARG(); if (get_u32(&pref, *argv, 0)) invarg("preference value is invalid\n", *argv); addattr32(&req.n, sizeof(req), FRA_PRIORITY, pref); } else if (strcmp(*argv, "tos") == 0 || matches(*argv, "dsfield") == 0) { __u32 tos; NEXT_ARG(); if (rtnl_dsfield_a2n(&tos, *argv)) invarg("TOS value is invalid\n", *argv); req.r.rtm_tos = tos; } else if (strcmp(*argv, "fwmark") == 0) { char *slash; __u32 fwmark, fwmask; NEXT_ARG(); slash = strchr(*argv, '/'); if (slash != NULL) *slash = '\0'; if (get_u32(&fwmark, *argv, 0)) invarg("fwmark value is invalid\n", *argv); addattr32(&req.n, sizeof(req), FRA_FWMARK, fwmark); if (slash) { if (get_u32(&fwmask, slash+1, 0)) invarg("fwmask value is invalid\n", slash+1); addattr32(&req.n, sizeof(req), FRA_FWMASK, fwmask); } } else if (matches(*argv, "realms") == 0) { __u32 realm; NEXT_ARG(); if (get_rt_realms_or_raw(&realm, *argv)) invarg("invalid realms\n", *argv); addattr32(&req.n, sizeof(req), FRA_FLOW, realm); } else if (matches(*argv, "table") == 0 || strcmp(*argv, "lookup") == 0) { NEXT_ARG(); if (rtnl_rttable_a2n(&tid, *argv)) invarg("invalid table ID\n", *argv); if (tid < 256) req.r.rtm_table = tid; else { req.r.rtm_table = RT_TABLE_UNSPEC; addattr32(&req.n, sizeof(req), FRA_TABLE, tid); } table_ok = 1; } else if (matches(*argv, "suppress_prefixlength") == 0 || strcmp(*argv, "sup_pl") == 0) { int pl; NEXT_ARG(); if (get_s32(&pl, *argv, 0) || pl < 0) invarg("suppress_prefixlength value is invalid\n", *argv); addattr32(&req.n, sizeof(req), FRA_SUPPRESS_PREFIXLEN, pl); } else if (matches(*argv, "suppress_ifgroup") == 0 || strcmp(*argv, "sup_group") == 0) { NEXT_ARG(); int group; if (rtnl_group_a2n(&group, *argv)) invarg("Invalid \"suppress_ifgroup\" value\n", *argv); addattr32(&req.n, sizeof(req), FRA_SUPPRESS_IFGROUP, group); } else if (strcmp(*argv, "dev") == 0 || strcmp(*argv, "iif") == 0) { NEXT_ARG(); if (check_ifname(*argv)) invarg("\"iif\"/\"dev\" not a valid ifname", *argv); addattr_l(&req.n, sizeof(req), FRA_IFNAME, *argv, strlen(*argv)+1); } else if (strcmp(*argv, "oif") == 0) { NEXT_ARG(); if (check_ifname(*argv)) invarg("\"oif\" not a valid ifname", *argv); addattr_l(&req.n, sizeof(req), FRA_OIFNAME, *argv, strlen(*argv)+1); } else if (strcmp(*argv, "l3mdev") == 0) { addattr8(&req.n, sizeof(req), FRA_L3MDEV, 1); table_ok = 1; l3mdev_rule = 1; } else if (strcmp(*argv, "uidrange") == 0) { struct fib_rule_uid_range r; NEXT_ARG(); if (sscanf(*argv, "%u-%u", &r.start, &r.end) != 2) invarg("invalid UID range\n", *argv); addattr_l(&req.n, sizeof(req), FRA_UID_RANGE, &r, sizeof(r)); } else if (strcmp(*argv, "nat") == 0 || matches(*argv, "map-to") == 0) { NEXT_ARG(); fprintf(stderr, "Warning: route NAT is deprecated\n"); addattr32(&req.n, sizeof(req), RTA_GATEWAY, get_addr32(*argv)); req.r.rtm_type = RTN_NAT; } else { int type; if (strcmp(*argv, "type") == 0) NEXT_ARG(); if (matches(*argv, "help") == 0) usage(); else if (matches(*argv, "goto") == 0) { __u32 target; type = FR_ACT_GOTO; NEXT_ARG(); if (get_u32(&target, *argv, 0)) invarg("invalid target\n", *argv); addattr32(&req.n, sizeof(req), FRA_GOTO, target); } else if (matches(*argv, "nop") == 0) type = FR_ACT_NOP; else if (rtnl_rtntype_a2n(&type, *argv)) invarg("Failed to parse rule type", *argv); req.r.rtm_type = type; table_ok = 1; } argc--; argv++; } if (l3mdev_rule && tid != 0) { fprintf(stderr, "table can not be specified for l3mdev rules\n"); return -EINVAL; } if (req.r.rtm_family == AF_UNSPEC) req.r.rtm_family = AF_INET; if (!table_ok && cmd == RTM_NEWRULE) req.r.rtm_table = RT_TABLE_MAIN; if (rtnl_talk(&rth, &req.n, NULL, 0) < 0) return -2; return 0; } int do_iprule(int argc, char **argv) { if (argc < 1) { return iprule_list_flush_or_save(0, NULL, IPRULE_LIST); } else if (matches(argv[0], "list") == 0 || matches(argv[0], "lst") == 0 || matches(argv[0], "show") == 0) { return iprule_list_flush_or_save(argc-1, argv+1, IPRULE_LIST); } else if (matches(argv[0], "save") == 0) { return iprule_list_flush_or_save(argc-1, argv+1, IPRULE_SAVE); } else if (matches(argv[0], "restore") == 0) { return iprule_restore(); } else if (matches(argv[0], "add") == 0) { return iprule_modify(RTM_NEWRULE, argc-1, argv+1); } else if (matches(argv[0], "delete") == 0) { return iprule_modify(RTM_DELRULE, argc-1, argv+1); } else if (matches(argv[0], "flush") == 0) { return iprule_list_flush_or_save(argc-1, argv+1, IPRULE_FLUSH); } else if (matches(argv[0], "help") == 0) usage(); fprintf(stderr, "Command \"%s\" is unknown, try \"ip rule help\".\n", *argv); exit(-1); } int do_multirule(int argc, char **argv) { switch (preferred_family) { case AF_UNSPEC: case AF_INET: preferred_family = RTNL_FAMILY_IPMR; break; case AF_INET6: preferred_family = RTNL_FAMILY_IP6MR; break; case RTNL_FAMILY_IPMR: case RTNL_FAMILY_IP6MR: break; default: fprintf(stderr, "Multicast rules are only supported for IPv4/IPv6, was: %i\n", preferred_family); exit(-1); } return do_iprule(argc, argv); }