Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
d6a61f80 CG |
2 | /* |
3 | * It is possible to use SO_REUSEPORT to open multiple sockets bound to | |
4 | * equivalent local addresses using AF_INET and AF_INET6 at the same time. If | |
5 | * the AF_INET6 socket has IPV6_V6ONLY set, it's clear which socket should | |
6 | * receive a given incoming packet. However, when it is not set, incoming v4 | |
7 | * packets should prefer the AF_INET socket(s). This behavior was defined with | |
8 | * the original SO_REUSEPORT implementation, but broke with | |
9 | * e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") | |
10 | * This test creates these mixed AF_INET/AF_INET6 sockets and asserts the | |
11 | * AF_INET preference for v4 packets. | |
12 | */ | |
13 | ||
14 | #define _GNU_SOURCE | |
15 | ||
16 | #include <arpa/inet.h> | |
17 | #include <errno.h> | |
18 | #include <error.h> | |
19 | #include <linux/in.h> | |
20 | #include <linux/unistd.h> | |
21 | #include <stdio.h> | |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include <sys/epoll.h> | |
25 | #include <sys/types.h> | |
26 | #include <sys/socket.h> | |
27 | #include <unistd.h> | |
28 | ||
29 | static const int PORT = 8888; | |
30 | ||
31 | static void build_rcv_fd(int family, int proto, int *rcv_fds, int count) | |
32 | { | |
33 | struct sockaddr_storage addr; | |
34 | struct sockaddr_in *addr4; | |
35 | struct sockaddr_in6 *addr6; | |
36 | int opt, i; | |
37 | ||
38 | switch (family) { | |
39 | case AF_INET: | |
40 | addr4 = (struct sockaddr_in *)&addr; | |
41 | addr4->sin_family = AF_INET; | |
42 | addr4->sin_addr.s_addr = htonl(INADDR_ANY); | |
43 | addr4->sin_port = htons(PORT); | |
44 | break; | |
45 | case AF_INET6: | |
46 | addr6 = (struct sockaddr_in6 *)&addr; | |
47 | addr6->sin6_family = AF_INET6; | |
48 | addr6->sin6_addr = in6addr_any; | |
49 | addr6->sin6_port = htons(PORT); | |
50 | break; | |
51 | default: | |
52 | error(1, 0, "Unsupported family %d", family); | |
53 | } | |
54 | ||
55 | for (i = 0; i < count; ++i) { | |
56 | rcv_fds[i] = socket(family, proto, 0); | |
57 | if (rcv_fds[i] < 0) | |
58 | error(1, errno, "failed to create receive socket"); | |
59 | ||
60 | opt = 1; | |
61 | if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt, | |
62 | sizeof(opt))) | |
63 | error(1, errno, "failed to set SO_REUSEPORT"); | |
64 | ||
65 | if (bind(rcv_fds[i], (struct sockaddr *)&addr, sizeof(addr))) | |
66 | error(1, errno, "failed to bind receive socket"); | |
67 | ||
68 | if (proto == SOCK_STREAM && listen(rcv_fds[i], 10)) | |
69 | error(1, errno, "failed to listen on receive port"); | |
70 | } | |
71 | } | |
72 | ||
73 | static void send_from_v4(int proto) | |
74 | { | |
75 | struct sockaddr_in saddr, daddr; | |
76 | int fd; | |
77 | ||
78 | saddr.sin_family = AF_INET; | |
79 | saddr.sin_addr.s_addr = htonl(INADDR_ANY); | |
80 | saddr.sin_port = 0; | |
81 | ||
82 | daddr.sin_family = AF_INET; | |
83 | daddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); | |
84 | daddr.sin_port = htons(PORT); | |
85 | ||
86 | fd = socket(AF_INET, proto, 0); | |
87 | if (fd < 0) | |
88 | error(1, errno, "failed to create send socket"); | |
89 | ||
90 | if (bind(fd, (struct sockaddr *)&saddr, sizeof(saddr))) | |
91 | error(1, errno, "failed to bind send socket"); | |
92 | ||
93 | if (connect(fd, (struct sockaddr *)&daddr, sizeof(daddr))) | |
94 | error(1, errno, "failed to connect send socket"); | |
95 | ||
96 | if (send(fd, "a", 1, 0) < 0) | |
97 | error(1, errno, "failed to send message"); | |
98 | ||
99 | close(fd); | |
100 | } | |
101 | ||
102 | static int receive_once(int epfd, int proto) | |
103 | { | |
104 | struct epoll_event ev; | |
105 | int i, fd; | |
106 | char buf[8]; | |
107 | ||
108 | i = epoll_wait(epfd, &ev, 1, -1); | |
109 | if (i < 0) | |
110 | error(1, errno, "epoll_wait failed"); | |
111 | ||
112 | if (proto == SOCK_STREAM) { | |
113 | fd = accept(ev.data.fd, NULL, NULL); | |
114 | if (fd < 0) | |
115 | error(1, errno, "failed to accept"); | |
116 | i = recv(fd, buf, sizeof(buf), 0); | |
117 | close(fd); | |
118 | } else { | |
119 | i = recv(ev.data.fd, buf, sizeof(buf), 0); | |
120 | } | |
121 | ||
122 | if (i < 0) | |
123 | error(1, errno, "failed to recv"); | |
124 | ||
125 | return ev.data.fd; | |
126 | } | |
127 | ||
128 | static void test(int *rcv_fds, int count, int proto) | |
129 | { | |
130 | struct epoll_event ev; | |
131 | int epfd, i, test_fd; | |
d64479a3 | 132 | int test_family; |
d6a61f80 CG |
133 | socklen_t len; |
134 | ||
135 | epfd = epoll_create(1); | |
136 | if (epfd < 0) | |
137 | error(1, errno, "failed to create epoll"); | |
138 | ||
139 | ev.events = EPOLLIN; | |
140 | for (i = 0; i < count; ++i) { | |
141 | ev.data.fd = rcv_fds[i]; | |
142 | if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev)) | |
143 | error(1, errno, "failed to register sock epoll"); | |
144 | } | |
145 | ||
146 | send_from_v4(proto); | |
147 | ||
148 | test_fd = receive_once(epfd, proto); | |
d64479a3 | 149 | len = sizeof(test_family); |
d6a61f80 CG |
150 | if (getsockopt(test_fd, SOL_SOCKET, SO_DOMAIN, &test_family, &len)) |
151 | error(1, errno, "failed to read socket domain"); | |
152 | if (test_family != AF_INET) | |
153 | error(1, 0, "expected to receive on v4 socket but got v6 (%d)", | |
154 | test_family); | |
155 | ||
156 | close(epfd); | |
157 | } | |
158 | ||
159 | int main(void) | |
160 | { | |
161 | int rcv_fds[32], i; | |
162 | ||
163 | fprintf(stderr, "---- UDP IPv4 created before IPv6 ----\n"); | |
164 | build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds, 5); | |
165 | build_rcv_fd(AF_INET6, SOCK_DGRAM, &(rcv_fds[5]), 5); | |
166 | test(rcv_fds, 10, SOCK_DGRAM); | |
167 | for (i = 0; i < 10; ++i) | |
168 | close(rcv_fds[i]); | |
169 | ||
170 | fprintf(stderr, "---- UDP IPv6 created before IPv4 ----\n"); | |
171 | build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds, 5); | |
172 | build_rcv_fd(AF_INET, SOCK_DGRAM, &(rcv_fds[5]), 5); | |
173 | test(rcv_fds, 10, SOCK_DGRAM); | |
174 | for (i = 0; i < 10; ++i) | |
175 | close(rcv_fds[i]); | |
176 | ||
177 | /* NOTE: UDP socket lookups traverse a different code path when there | |
178 | * are > 10 sockets in a group. | |
179 | */ | |
180 | fprintf(stderr, "---- UDP IPv4 created before IPv6 (large) ----\n"); | |
181 | build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds, 16); | |
182 | build_rcv_fd(AF_INET6, SOCK_DGRAM, &(rcv_fds[16]), 16); | |
183 | test(rcv_fds, 32, SOCK_DGRAM); | |
184 | for (i = 0; i < 32; ++i) | |
185 | close(rcv_fds[i]); | |
186 | ||
187 | fprintf(stderr, "---- UDP IPv6 created before IPv4 (large) ----\n"); | |
188 | build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds, 16); | |
189 | build_rcv_fd(AF_INET, SOCK_DGRAM, &(rcv_fds[16]), 16); | |
190 | test(rcv_fds, 32, SOCK_DGRAM); | |
191 | for (i = 0; i < 32; ++i) | |
192 | close(rcv_fds[i]); | |
193 | ||
194 | fprintf(stderr, "---- TCP IPv4 created before IPv6 ----\n"); | |
195 | build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds, 5); | |
196 | build_rcv_fd(AF_INET6, SOCK_STREAM, &(rcv_fds[5]), 5); | |
197 | test(rcv_fds, 10, SOCK_STREAM); | |
198 | for (i = 0; i < 10; ++i) | |
199 | close(rcv_fds[i]); | |
200 | ||
201 | fprintf(stderr, "---- TCP IPv6 created before IPv4 ----\n"); | |
202 | build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds, 5); | |
203 | build_rcv_fd(AF_INET, SOCK_STREAM, &(rcv_fds[5]), 5); | |
204 | test(rcv_fds, 10, SOCK_STREAM); | |
205 | for (i = 0; i < 10; ++i) | |
206 | close(rcv_fds[i]); | |
207 | ||
208 | fprintf(stderr, "SUCCESS\n"); | |
209 | return 0; | |
210 | } |