| /* |
| * m_nat.c NAT module |
| * |
| * This program is free software; you can distribute 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: Herbert Xu <herbert@gondor.apana.org.au> |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <syslog.h> |
| #include <fcntl.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <string.h> |
| #include <dlfcn.h> |
| #include "utils.h" |
| #include "tc_util.h" |
| #include <linux/tc_act/tc_nat.h> |
| |
| static void |
| explain(void) |
| { |
| fprintf(stderr, "Usage: ... nat NAT\n" |
| "NAT := DIRECTION OLD NEW\n" |
| "DIRECTION := { ingress | egress }\n" |
| "OLD := PREFIX\n" |
| "NEW := ADDRESS\n"); |
| } |
| |
| static void |
| usage(void) |
| { |
| explain(); |
| exit(-1); |
| } |
| |
| static int |
| parse_nat_args(int *argc_p, char ***argv_p,struct tc_nat *sel) |
| { |
| int argc = *argc_p; |
| char **argv = *argv_p; |
| inet_prefix addr; |
| |
| if (argc <= 0) |
| return -1; |
| |
| if (matches(*argv, "egress") == 0) |
| sel->flags |= TCA_NAT_FLAG_EGRESS; |
| else if (matches(*argv, "ingress") != 0) |
| goto bad_val; |
| |
| NEXT_ARG(); |
| |
| if (get_prefix_1(&addr, *argv, AF_INET)) |
| goto bad_val; |
| |
| sel->old_addr = addr.data[0]; |
| sel->mask = htonl(~0u << (32 - addr.bitlen)); |
| |
| NEXT_ARG(); |
| |
| if (get_prefix_1(&addr, *argv, AF_INET)) |
| goto bad_val; |
| |
| sel->new_addr = addr.data[0]; |
| |
| argc--; |
| argv++; |
| |
| *argc_p = argc; |
| *argv_p = argv; |
| return 0; |
| |
| bad_val: |
| return -1; |
| } |
| |
| static int |
| parse_nat(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n) |
| { |
| struct tc_nat sel; |
| |
| int argc = *argc_p; |
| char **argv = *argv_p; |
| int ok = 0; |
| struct rtattr *tail; |
| |
| memset(&sel, 0, sizeof(sel)); |
| |
| while (argc > 0) { |
| if (matches(*argv, "nat") == 0) { |
| NEXT_ARG(); |
| if (parse_nat_args(&argc, &argv, &sel)) { |
| fprintf(stderr, "Illegal nat construct (%s) \n", |
| *argv); |
| explain(); |
| return -1; |
| } |
| ok++; |
| continue; |
| } else if (matches(*argv, "help") == 0) { |
| usage(); |
| } else { |
| break; |
| } |
| |
| } |
| |
| if (!ok) { |
| explain(); |
| return -1; |
| } |
| |
| if (argc) { |
| if (matches(*argv, "reclassify") == 0) { |
| sel.action = TC_ACT_RECLASSIFY; |
| argc--; |
| argv++; |
| } else if (matches(*argv, "pipe") == 0) { |
| sel.action = TC_ACT_PIPE; |
| argc--; |
| argv++; |
| } else if (matches(*argv, "drop") == 0 || |
| matches(*argv, "shot") == 0) { |
| sel.action = TC_ACT_SHOT; |
| argc--; |
| argv++; |
| } else if (matches(*argv, "continue") == 0) { |
| sel.action = TC_ACT_UNSPEC; |
| argc--; |
| argv++; |
| } else if (matches(*argv, "pass") == 0) { |
| sel.action = TC_ACT_OK; |
| argc--; |
| argv++; |
| } |
| } |
| |
| if (argc) { |
| if (matches(*argv, "index") == 0) { |
| NEXT_ARG(); |
| if (get_u32(&sel.index, *argv, 10)) { |
| fprintf(stderr, "Pedit: Illegal \"index\"\n"); |
| return -1; |
| } |
| argc--; |
| argv++; |
| } |
| } |
| |
| tail = NLMSG_TAIL(n); |
| addattr_l(n, MAX_MSG, tca_id, NULL, 0); |
| addattr_l(n, MAX_MSG, TCA_NAT_PARMS, &sel, sizeof(sel)); |
| tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail; |
| |
| *argc_p = argc; |
| *argv_p = argv; |
| return 0; |
| } |
| |
| static int |
| print_nat(struct action_util *au,FILE * f, struct rtattr *arg) |
| { |
| struct tc_nat *sel; |
| struct rtattr *tb[TCA_NAT_MAX + 1]; |
| char buf1[256]; |
| char buf2[256]; |
| SPRINT_BUF(buf3); |
| int len; |
| |
| if (arg == NULL) |
| return -1; |
| |
| parse_rtattr_nested(tb, TCA_NAT_MAX, arg); |
| |
| if (tb[TCA_NAT_PARMS] == NULL) { |
| fprintf(f, "[NULL nat parameters]"); |
| return -1; |
| } |
| sel = RTA_DATA(tb[TCA_NAT_PARMS]); |
| |
| len = ffs(sel->mask); |
| len = len ? 33 - len : 0; |
| |
| fprintf(f, " nat %s %s/%d %s %s", sel->flags & TCA_NAT_FLAG_EGRESS ? |
| "egress" : "ingress", |
| format_host(AF_INET, 4, &sel->old_addr, buf1, sizeof(buf1)), |
| len, |
| format_host(AF_INET, 4, &sel->new_addr, buf2, sizeof(buf2)), |
| action_n2a(sel->action, buf3, sizeof (buf3))); |
| |
| if (show_stats) { |
| if (tb[TCA_NAT_TM]) { |
| struct tcf_t *tm = RTA_DATA(tb[TCA_NAT_TM]); |
| print_tm(f,tm); |
| } |
| } |
| |
| return 0; |
| } |
| |
| struct action_util nat_action_util = { |
| .id = "nat", |
| .parse_aopt = parse_nat, |
| .print_aopt = print_nat, |
| }; |