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
usage(void)26 static void usage(void)
27 {
28 fprintf(stderr, "Usage: ip fou add port PORT { ipproto PROTO | gue }\n");
29 fprintf(stderr, " ip fou del port PORT\n");
30 fprintf(stderr, "\n");
31 fprintf(stderr, "Where: PROTO { ipproto-name | 1..255 }\n");
32 fprintf(stderr, " PORT { 1..65535 }\n");
33
34 exit(-1);
35 }
36
37 /* netlink socket */
38 static struct rtnl_handle genl_rth = { .fd = -1 };
39 static int genl_family = -1;
40
41 #define FOU_REQUEST(_req, _bufsiz, _cmd, _flags) \
42 GENL_REQUEST(_req, _bufsiz, genl_family, 0, \
43 FOU_GENL_VERSION, _cmd, _flags)
44
fou_parse_opt(int argc,char ** argv,struct nlmsghdr * n,bool adding)45 static int fou_parse_opt(int argc, char **argv, struct nlmsghdr *n,
46 bool adding)
47 {
48 __u16 port;
49 int port_set = 0;
50 __u8 ipproto, type;
51 bool gue_set = false;
52 int ipproto_set = 0;
53
54 while (argc > 0) {
55 if (!matches(*argv, "port")) {
56 NEXT_ARG();
57
58 if (get_u16(&port, *argv, 0) || port == 0)
59 invarg("invalid port", *argv);
60 port = htons(port);
61 port_set = 1;
62 } else if (!matches(*argv, "ipproto")) {
63 struct protoent *servptr;
64
65 NEXT_ARG();
66
67 servptr = getprotobyname(*argv);
68 if (servptr)
69 ipproto = servptr->p_proto;
70 else if (get_u8(&ipproto, *argv, 0) || ipproto == 0)
71 invarg("invalid ipproto", *argv);
72 ipproto_set = 1;
73 } else if (!matches(*argv, "gue")) {
74 gue_set = true;
75 } else {
76 fprintf(stderr, "fou: unknown command \"%s\"?\n", *argv);
77 usage();
78 return -1;
79 }
80 argc--, argv++;
81 }
82
83 if (!port_set) {
84 fprintf(stderr, "fou: missing port\n");
85 return -1;
86 }
87
88 if (!ipproto_set && !gue_set && adding) {
89 fprintf(stderr, "fou: must set ipproto or gue\n");
90 return -1;
91 }
92
93 if (ipproto_set && gue_set) {
94 fprintf(stderr, "fou: cannot set ipproto and gue\n");
95 return -1;
96 }
97
98 type = gue_set ? FOU_ENCAP_GUE : FOU_ENCAP_DIRECT;
99
100 addattr16(n, 1024, FOU_ATTR_PORT, port);
101 addattr8(n, 1024, FOU_ATTR_TYPE, type);
102
103 if (ipproto_set)
104 addattr8(n, 1024, FOU_ATTR_IPPROTO, ipproto);
105
106 return 0;
107 }
108
do_add(int argc,char ** argv)109 static int do_add(int argc, char **argv)
110 {
111 FOU_REQUEST(req, 1024, FOU_CMD_ADD, NLM_F_REQUEST);
112
113 fou_parse_opt(argc, argv, &req.n, true);
114
115 if (rtnl_talk(&genl_rth, &req.n, NULL, 0) < 0)
116 return -2;
117
118 return 0;
119 }
120
do_del(int argc,char ** argv)121 static int do_del(int argc, char **argv)
122 {
123 FOU_REQUEST(req, 1024, FOU_CMD_DEL, NLM_F_REQUEST);
124
125 fou_parse_opt(argc, argv, &req.n, false);
126
127 if (rtnl_talk(&genl_rth, &req.n, NULL, 0) < 0)
128 return -2;
129
130 return 0;
131 }
132
do_ipfou(int argc,char ** argv)133 int do_ipfou(int argc, char **argv)
134 {
135 if (genl_family < 0) {
136 if (rtnl_open_byproto(&genl_rth, 0, NETLINK_GENERIC) < 0) {
137 fprintf(stderr, "Cannot open generic netlink socket\n");
138 exit(1);
139 }
140
141 genl_family = genl_resolve_family(&genl_rth, FOU_GENL_NAME);
142 if (genl_family < 0)
143 exit(1);
144 }
145
146 if (argc < 1)
147 usage();
148
149 if (matches(*argv, "add") == 0)
150 return do_add(argc-1, argv+1);
151 if (matches(*argv, "delete") == 0)
152 return do_del(argc-1, argv+1);
153 if (matches(*argv, "help") == 0)
154 usage();
155
156 fprintf(stderr, "Command \"%s\" is unknown, try \"ip fou help\".\n", *argv);
157 exit(-1);
158 }
159