ip/ipfou.c

   1 /*
   2  * ipfou.c      FOU (foo over UDP) support
   3  *
   4  *              This program is free software; you can redistribute 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:     Tom Herbert <therbert@google.com>
  10  */
  11
  12 #include <netdb.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <net/if.h>
  17 #include <linux/fou.h>
  18 #include <linux/genetlink.h>
  19 #include <linux/ip.h>
  20 #include <arpa/inet.h>
  21
  22 #include "libgenl.h"
  23 #include "utils.h"
  24 #include "ip_common.h"
  25
  26 static void usage(void)
  27 {
  28         fprintf(stderr, "Usage: ip fou add port PORT "
  29                 "{ ipproto PROTO  | gue } [ -6 ]\n");
  30         fprintf(stderr, "       ip fou del port PORT [ -6 ]\n");
  31         fprintf(stderr, "\n");
  32         fprintf(stderr, "Where: PROTO { ipproto-name | 1..255 }\n");
  33         fprintf(stderr, "       PORT { 1..65535 }\n");
  34
  35         exit(-1);
  36 }
  37
  38 /* netlink socket */
  39 static struct rtnl_handle genl_rth = { .fd = -1 };
  40 static int genl_family = -1;
  41
  42 #define FOU_REQUEST(_req, _bufsiz, _cmd, _flags)        \
  43         GENL_REQUEST(_req, _bufsiz, genl_family, 0,     \
  44                      FOU_GENL_VERSION, _cmd, _flags)
  45
  46 static int fou_parse_opt(int argc, char **argv, struct nlmsghdr *n,
  47                          bool adding)
  48 {
  49         __u16 port;
  50         int port_set = 0;
  51         __u8 ipproto, type;
  52         bool gue_set = false;
  53         int ipproto_set = 0;
  54         unsigned short family = AF_INET;
  55
  56         while (argc > 0) {
  57                 if (!matches(*argv, "port")) {
  58                         NEXT_ARG();
  59
  60                         if (get_be16(&port, *argv, 0) || port == 0)
  61                                 invarg("invalid port", *argv);
  62                         port_set = 1;
  63                 } else if (!matches(*argv, "ipproto")) {
  64                         struct protoent *servptr;
  65
  66                         NEXT_ARG();
  67
  68                         servptr = getprotobyname(*argv);
  69                         if (servptr)
  70                                 ipproto = servptr->p_proto;
  71                         else if (get_u8(&ipproto, *argv, 0) || ipproto == 0)
  72                                 invarg("invalid ipproto", *argv);
  73                         ipproto_set = 1;
  74                 } else if (!matches(*argv, "gue")) {
  75                         gue_set = true;
  76                 } else if (!matches(*argv, "-6")) {
  77                         family = AF_INET6;
  78                 } else {
  79                         fprintf(stderr, "fou: unknown command \"%s\"?\n", *argv);
  80                         usage();
  81                         return -1;
  82                 }
  83                 argc--, argv++;
  84         }
  85
  86         if (!port_set) {
  87                 fprintf(stderr, "fou: missing port\n");
  88                 return -1;
  89         }
  90
  91         if (!ipproto_set && !gue_set && adding) {
  92                 fprintf(stderr, "fou: must set ipproto or gue\n");
  93                 return -1;
  94         }
  95
  96         if (ipproto_set && gue_set) {
  97                 fprintf(stderr, "fou: cannot set ipproto and gue\n");
  98                 return -1;
  99         }
 100
 101         type = gue_set ? FOU_ENCAP_GUE : FOU_ENCAP_DIRECT;
 102
 103         addattr16(n, 1024, FOU_ATTR_PORT, port);
 104         addattr8(n, 1024, FOU_ATTR_TYPE, type);
 105         addattr16(n, 1024, FOU_ATTR_AF, family);
 106
 107         if (ipproto_set)
 108                 addattr8(n, 1024, FOU_ATTR_IPPROTO, ipproto);
 109
 110         return 0;
 111 }
 112
 113 static int do_add(int argc, char **argv)
 114 {
 115         FOU_REQUEST(req, 1024, FOU_CMD_ADD, NLM_F_REQUEST);
 116
 117         fou_parse_opt(argc, argv, &req.n, true);
 118
 119         if (rtnl_talk(&genl_rth, &req.n, NULL) < 0)
 120                 return -2;
 121
 122         return 0;
 123 }
 124
 125 static int do_del(int argc, char **argv)
 126 {
 127         FOU_REQUEST(req, 1024, FOU_CMD_DEL, NLM_F_REQUEST);
 128
 129         fou_parse_opt(argc, argv, &req.n, false);
 130
 131         if (rtnl_talk(&genl_rth, &req.n, NULL) < 0)
 132                 return -2;
 133
 134         return 0;
 135 }
 136
 137 int do_ipfou(int argc, char **argv)
 138 {
 139         if (argc < 1)
 140                 usage();
 141
 142         if (matches(*argv, "help") == 0)
 143                 usage();
 144
 145         if (genl_init_handle(&genl_rth, FOU_GENL_NAME, &genl_family))
 146                 exit(1);
 147
 148         if (matches(*argv, "add") == 0)
 149                 return do_add(argc-1, argv+1);
 150         if (matches(*argv, "delete") == 0)
 151                 return do_del(argc-1, argv+1);
 152         fprintf(stderr, "Command \"%s\" is unknown, try \"ip fou help\".\n", *argv);
 153         exit(-1);
 154 }