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