1 // SPDX-License-Identifier: GPL-2.0
2 /* Test IPV6_FLOWINFO cmsg on send and recv */
3
4 #define _GNU_SOURCE
5
6 #include <arpa/inet.h>
7 #include <asm/byteorder.h>
8 #include <error.h>
9 #include <errno.h>
10 #include <fcntl.h>
11 #include <limits.h>
12 #include <linux/icmpv6.h>
13 #include <linux/in6.h>
14 #include <stdbool.h>
15 #include <stdio.h>
16 #include <stdint.h>
17 #include <stdlib.h>
18 #include <string.h>
19 #include <sys/socket.h>
20 #include <sys/stat.h>
21 #include <sys/time.h>
22 #include <sys/types.h>
23 #include <unistd.h>
24
25 /* uapi/glibc weirdness may leave this undefined */
26 #ifndef IPV6_FLOWINFO
27 #define IPV6_FLOWINFO 11
28 #endif
29
30 #ifndef IPV6_FLOWLABEL_MGR
31 #define IPV6_FLOWLABEL_MGR 32
32 #endif
33 #ifndef IPV6_FLOWINFO_SEND
34 #define IPV6_FLOWINFO_SEND 33
35 #endif
36
37 #define FLOWLABEL_WILDCARD ((uint32_t) -1)
38
39 static const char cfg_data[] = "a";
40 static uint32_t cfg_label = 1;
41 static bool use_ping;
42 static bool use_flowinfo_send;
43
44 static struct icmp6hdr icmp6 = {
45 .icmp6_type = ICMPV6_ECHO_REQUEST
46 };
47
48 static struct sockaddr_in6 addr = {
49 .sin6_family = AF_INET6,
50 .sin6_addr = IN6ADDR_LOOPBACK_INIT,
51 };
52
53 static void do_send(int fd, bool with_flowlabel, uint32_t flowlabel)
54 {
55 char control[CMSG_SPACE(sizeof(flowlabel))] = {0};
56 struct msghdr msg = {0};
57 struct iovec iov = {
58 .iov_base = (char *)cfg_data,
59 .iov_len = sizeof(cfg_data)
60 };
61 int ret;
62
63 if (use_ping) {
64 iov.iov_base = &icmp6;
65 iov.iov_len = sizeof(icmp6);
66 }
67
68 msg.msg_iov = &iov;
69 msg.msg_iovlen = 1;
70
71 if (use_flowinfo_send) {
72 msg.msg_name = &addr;
73 msg.msg_namelen = sizeof(addr);
74 } else if (with_flowlabel) {
75 struct cmsghdr *cm;
76
77 cm = (void *)control;
78 cm->cmsg_len = CMSG_LEN(sizeof(flowlabel));
79 cm->cmsg_level = SOL_IPV6;
80 cm->cmsg_type = IPV6_FLOWINFO;
81 *(uint32_t *)CMSG_DATA(cm) = htonl(flowlabel);
82
83 msg.msg_control = control;
84 msg.msg_controllen = sizeof(control);
85 }
86
87 ret = sendmsg(fd, &msg, 0);
88 if (ret == -1)
89 error(1, errno, "send");
90
91 if (with_flowlabel)
92 fprintf(stderr, "sent with label %u\n", flowlabel);
93 else
94 fprintf(stderr, "sent without label\n");
95 }
96
97 static void do_recv(int fd, bool with_flowlabel, uint32_t expect)
98 {
99 char control[CMSG_SPACE(sizeof(expect))];
100 char data[sizeof(cfg_data)];
101 struct msghdr msg = {0};
102 struct iovec iov = {0};
103 struct cmsghdr *cm;
104 uint32_t flowlabel;
105 int ret;
106
107 iov.iov_base = data;
108 iov.iov_len = sizeof(data);
109
110 msg.msg_iov = &iov;
111 msg.msg_iovlen = 1;
112
113 memset(control, 0, sizeof(control));
114 msg.msg_control = control;
115 msg.msg_controllen = sizeof(control);
116
117 ret = recvmsg(fd, &msg, 0);
118 if (ret == -1)
119 error(1, errno, "recv");
120 if (use_ping)
121 goto parse_cmsg;
122 if (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))
123 error(1, 0, "recv: truncated");
124 if (ret != sizeof(cfg_data))
125 error(1, 0, "recv: length mismatch");
126 if (memcmp(data, cfg_data, sizeof(data)))
127 error(1, 0, "recv: data mismatch");
128
129 parse_cmsg:
130 cm = CMSG_FIRSTHDR(&msg);
131 if (with_flowlabel) {
132 if (!cm)
133 error(1, 0, "recv: missing cmsg");
134 if (CMSG_NXTHDR(&msg, cm))
135 error(1, 0, "recv: too many cmsg");
136 if (cm->cmsg_level != SOL_IPV6 ||
137 cm->cmsg_type != IPV6_FLOWINFO)
138 error(1, 0, "recv: unexpected cmsg level or type");
139
140 flowlabel = ntohl(*(uint32_t *)CMSG_DATA(cm));
141 fprintf(stderr, "recv with label %u\n", flowlabel);
142
143 if (expect != FLOWLABEL_WILDCARD && expect != flowlabel) {
144 fprintf(stderr, "recv: incorrect flowlabel %u != %u\n",
145 flowlabel, expect);
146 error(1, 0, "recv: flowlabel is wrong");
147 }
148
149 } else {
150 fprintf(stderr, "recv without label\n");
151 }
152 }
153
154 static bool get_autoflowlabel_enabled(void)
155 {
156 int fd, ret;
157 char val;
158
159 fd = open("/proc/sys/net/ipv6/auto_flowlabels", O_RDONLY);
160 if (fd == -1)
161 error(1, errno, "open sysctl");
162
163 ret = read(fd, &val, 1);
164 if (ret == -1)
165 error(1, errno, "read sysctl");
166 if (ret == 0)
167 error(1, 0, "read sysctl: 0");
168
169 if (close(fd))
170 error(1, errno, "close sysctl");
171
172 return val == '1';
173 }
174
175 static void flowlabel_get(int fd, uint32_t label, uint8_t share, uint16_t flags)
176 {
177 struct in6_flowlabel_req req = {
178 .flr_action = IPV6_FL_A_GET,
179 .flr_label = htonl(label),
180 .flr_flags = flags,
181 .flr_share = share,
182 };
183
184 /* do not pass IPV6_ADDR_ANY or IPV6_ADDR_MAPPED */
185 req.flr_dst.s6_addr[0] = 0xfd;
186 req.flr_dst.s6_addr[15] = 0x1;
187
188 if (setsockopt(fd, SOL_IPV6, IPV6_FLOWLABEL_MGR, &req, sizeof(req)))
189 error(1, errno, "setsockopt flowlabel get");
190 }
191
192 static void parse_opts(int argc, char **argv)
193 {
194 int c;
195
196 while ((c = getopt(argc, argv, "l:ps")) != -1) {
197 switch (c) {
198 case 'l':
199 cfg_label = strtoul(optarg, NULL, 0);
200 break;
201 case 'p':
202 use_ping = true;
203 break;
204 case 's':
205 use_flowinfo_send = true;
206 break;
207 default:
208 error(1, 0, "%s: parse error", argv[0]);
209 }
210 }
211 }
212
213 int main(int argc, char **argv)
214 {
215 const int one = 1;
216 int fdt, fdr;
217 int prot = 0;
218
219 addr.sin6_port = htons(8000);
220
221 parse_opts(argc, argv);
222
223 if (use_ping) {
224 fprintf(stderr, "attempting to use ping sockets\n");
225 prot = IPPROTO_ICMPV6;
226 }
227
228 fdt = socket(PF_INET6, SOCK_DGRAM, prot);
229 if (fdt == -1)
230 error(1, errno, "socket t");
231
232 fdr = use_ping ? fdt : socket(PF_INET6, SOCK_DGRAM, 0);
233 if (fdr == -1)
234 error(1, errno, "socket r");
235
236 if (connect(fdt, (void *)&addr, sizeof(addr)))
237 error(1, errno, "connect");
238 if (!use_ping && bind(fdr, (void *)&addr, sizeof(addr)))
239 error(1, errno, "bind");
240
241 flowlabel_get(fdt, cfg_label, IPV6_FL_S_EXCL, IPV6_FL_F_CREATE);
242
243 if (setsockopt(fdr, SOL_IPV6, IPV6_FLOWINFO, &one, sizeof(one)))
244 error(1, errno, "setsockopt flowinfo");
245
246 if (get_autoflowlabel_enabled()) {
247 fprintf(stderr, "send no label: recv auto flowlabel\n");
248 do_send(fdt, false, 0);
249 do_recv(fdr, true, FLOWLABEL_WILDCARD);
250 } else {
251 fprintf(stderr, "send no label: recv no label (auto off)\n");
252 do_send(fdt, false, 0);
253 do_recv(fdr, false, 0);
254 }
255
256 if (use_flowinfo_send) {
257 fprintf(stderr, "using IPV6_FLOWINFO_SEND to send label\n");
258 addr.sin6_flowinfo = htonl(cfg_label);
259 if (setsockopt(fdt, SOL_IPV6, IPV6_FLOWINFO_SEND, &one,
260 sizeof(one)) == -1)
261 error(1, errno, "setsockopt flowinfo_send");
262 }
263
264 fprintf(stderr, "send label\n");
265 do_send(fdt, true, cfg_label);
266 do_recv(fdr, true, cfg_label);
267
268 if (close(fdr))
269 error(1, errno, "close r");
270 if (!use_ping && close(fdt))
271 error(1, errno, "close t");
272
273 return 0;
274 }
275
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