Herbert Xu | fc2d020 | 2007-10-12 17:08:40 +0800 | [diff] [blame] | 1 | /* |
| 2 | * m_nat.c NAT module |
| 3 | * |
| 4 | * This program is free software; you can distribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Herbert Xu <herbert@gondor.apana.org.au> |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <stdio.h> |
| 14 | #include <stdlib.h> |
| 15 | #include <unistd.h> |
| 16 | #include <syslog.h> |
| 17 | #include <fcntl.h> |
| 18 | #include <sys/socket.h> |
| 19 | #include <netinet/in.h> |
| 20 | #include <arpa/inet.h> |
| 21 | #include <string.h> |
| 22 | #include <dlfcn.h> |
| 23 | #include "utils.h" |
| 24 | #include "tc_util.h" |
| 25 | #include <linux/tc_act/tc_nat.h> |
| 26 | |
| 27 | static void |
| 28 | explain(void) |
| 29 | { |
| 30 | fprintf(stderr, "Usage: ... nat NAT\n" |
| 31 | "NAT := DIRECTION OLD NEW\n" |
| 32 | "DIRECTION := { ingress | egress }\n" |
| 33 | "OLD := PREFIX\n" |
| 34 | "NEW := ADDRESS\n"); |
| 35 | } |
| 36 | |
| 37 | static void |
| 38 | usage(void) |
| 39 | { |
| 40 | explain(); |
| 41 | exit(-1); |
| 42 | } |
| 43 | |
| 44 | static int |
| 45 | parse_nat_args(int *argc_p, char ***argv_p,struct tc_nat *sel) |
| 46 | { |
| 47 | int argc = *argc_p; |
| 48 | char **argv = *argv_p; |
| 49 | inet_prefix addr; |
| 50 | |
| 51 | if (argc <= 0) |
| 52 | return -1; |
| 53 | |
| 54 | if (matches(*argv, "egress") == 0) |
| 55 | sel->flags |= TCA_NAT_FLAG_EGRESS; |
| 56 | else if (matches(*argv, "ingress") != 0) |
| 57 | goto bad_val; |
| 58 | |
| 59 | NEXT_ARG(); |
| 60 | |
| 61 | if (get_prefix_1(&addr, *argv, AF_INET)) |
| 62 | goto bad_val; |
| 63 | |
| 64 | sel->old_addr = addr.data[0]; |
| 65 | sel->mask = htonl(~0u << (32 - addr.bitlen)); |
| 66 | |
| 67 | NEXT_ARG(); |
| 68 | |
| 69 | if (get_prefix_1(&addr, *argv, AF_INET)) |
| 70 | goto bad_val; |
| 71 | |
| 72 | sel->new_addr = addr.data[0]; |
| 73 | |
| 74 | argc--; |
| 75 | argv++; |
| 76 | |
| 77 | *argc_p = argc; |
| 78 | *argv_p = argv; |
| 79 | return 0; |
| 80 | |
| 81 | bad_val: |
| 82 | return -1; |
| 83 | } |
| 84 | |
| 85 | static int |
| 86 | parse_nat(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n) |
| 87 | { |
| 88 | struct tc_nat sel; |
| 89 | |
| 90 | int argc = *argc_p; |
| 91 | char **argv = *argv_p; |
| 92 | int ok = 0; |
| 93 | struct rtattr *tail; |
| 94 | |
| 95 | memset(&sel, 0, sizeof(sel)); |
| 96 | |
| 97 | while (argc > 0) { |
| 98 | if (matches(*argv, "nat") == 0) { |
| 99 | NEXT_ARG(); |
| 100 | if (parse_nat_args(&argc, &argv, &sel)) { |
| 101 | fprintf(stderr, "Illegal nat construct (%s) \n", |
| 102 | *argv); |
| 103 | explain(); |
| 104 | return -1; |
| 105 | } |
| 106 | ok++; |
| 107 | continue; |
| 108 | } else if (matches(*argv, "help") == 0) { |
| 109 | usage(); |
| 110 | } else { |
| 111 | break; |
| 112 | } |
| 113 | |
| 114 | } |
| 115 | |
| 116 | if (!ok) { |
| 117 | explain(); |
| 118 | return -1; |
| 119 | } |
| 120 | |
| 121 | if (argc) { |
| 122 | if (matches(*argv, "reclassify") == 0) { |
| 123 | sel.action = TC_ACT_RECLASSIFY; |
| 124 | argc--; |
| 125 | argv++; |
| 126 | } else if (matches(*argv, "pipe") == 0) { |
| 127 | sel.action = TC_ACT_PIPE; |
| 128 | argc--; |
| 129 | argv++; |
| 130 | } else if (matches(*argv, "drop") == 0 || |
| 131 | matches(*argv, "shot") == 0) { |
| 132 | sel.action = TC_ACT_SHOT; |
| 133 | argc--; |
| 134 | argv++; |
| 135 | } else if (matches(*argv, "continue") == 0) { |
| 136 | sel.action = TC_ACT_UNSPEC; |
| 137 | argc--; |
| 138 | argv++; |
| 139 | } else if (matches(*argv, "pass") == 0) { |
| 140 | sel.action = TC_ACT_OK; |
| 141 | argc--; |
| 142 | argv++; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | if (argc) { |
| 147 | if (matches(*argv, "index") == 0) { |
| 148 | NEXT_ARG(); |
| 149 | if (get_u32(&sel.index, *argv, 10)) { |
| 150 | fprintf(stderr, "Pedit: Illegal \"index\"\n"); |
| 151 | return -1; |
| 152 | } |
| 153 | argc--; |
| 154 | argv++; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | tail = NLMSG_TAIL(n); |
| 159 | addattr_l(n, MAX_MSG, tca_id, NULL, 0); |
| 160 | addattr_l(n, MAX_MSG, TCA_NAT_PARMS, &sel, sizeof(sel)); |
| 161 | tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail; |
| 162 | |
| 163 | *argc_p = argc; |
| 164 | *argv_p = argv; |
| 165 | return 0; |
| 166 | } |
| 167 | |
| 168 | static int |
| 169 | print_nat(struct action_util *au,FILE * f, struct rtattr *arg) |
| 170 | { |
| 171 | struct tc_nat *sel; |
| 172 | struct rtattr *tb[TCA_NAT_MAX + 1]; |
| 173 | char buf1[256]; |
| 174 | char buf2[256]; |
| 175 | SPRINT_BUF(buf3); |
| 176 | int len; |
| 177 | |
| 178 | if (arg == NULL) |
| 179 | return -1; |
| 180 | |
| 181 | parse_rtattr_nested(tb, TCA_NAT_MAX, arg); |
| 182 | |
| 183 | if (tb[TCA_NAT_PARMS] == NULL) { |
| 184 | fprintf(f, "[NULL nat parameters]"); |
| 185 | return -1; |
| 186 | } |
| 187 | sel = RTA_DATA(tb[TCA_NAT_PARMS]); |
| 188 | |
| 189 | len = ffs(sel->mask); |
| 190 | len = len ? 33 - len : 0; |
| 191 | |
| 192 | fprintf(f, " nat %s %s/%d %s %s", sel->flags & TCA_NAT_FLAG_EGRESS ? |
| 193 | "egress" : "ingress", |
| 194 | format_host(AF_INET, 4, &sel->old_addr, buf1, sizeof(buf1)), |
| 195 | len, |
| 196 | format_host(AF_INET, 4, &sel->new_addr, buf2, sizeof(buf2)), |
| 197 | action_n2a(sel->action, buf3, sizeof (buf3))); |
| 198 | |
| 199 | if (show_stats) { |
| 200 | if (tb[TCA_NAT_TM]) { |
| 201 | struct tcf_t *tm = RTA_DATA(tb[TCA_NAT_TM]); |
| 202 | print_tm(f,tm); |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | return 0; |
| 207 | } |
| 208 | |
| 209 | struct action_util nat_action_util = { |
| 210 | .id = "nat", |
| 211 | .parse_aopt = parse_nat, |
| 212 | .print_aopt = print_nat, |
| 213 | }; |