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(p: data, q: cfg_data, size: 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(fd: fdt, label: 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(fd: fdt, with_flowlabel: false, flowlabel: 0); |
249 | do_recv(fd: fdr, with_flowlabel: true, FLOWLABEL_WILDCARD); |
250 | } else { |
251 | fprintf(stderr, "send no label: recv no label (auto off)\n" ); |
252 | do_send(fd: fdt, with_flowlabel: false, flowlabel: 0); |
253 | do_recv(fd: fdr, with_flowlabel: false, expect: 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(fd: fdt, with_flowlabel: true, flowlabel: cfg_label); |
266 | do_recv(fd: fdr, with_flowlabel: true, expect: 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 | |