--- /dev/null
+/*
+ * It is possible to use SO_REUSEPORT to open multiple sockets bound to
+ * equivalent local addresses using AF_INET and AF_INET6 at the same time. If
+ * the AF_INET6 socket has IPV6_V6ONLY set, it's clear which socket should
+ * receive a given incoming packet. However, when it is not set, incoming v4
+ * packets should prefer the AF_INET socket(s). This behavior was defined with
+ * the original SO_REUSEPORT implementation, but broke with
+ * e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection")
+ * This test creates these mixed AF_INET/AF_INET6 sockets and asserts the
+ * AF_INET preference for v4 packets.
+ */
+
+#define _GNU_SOURCE
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <error.h>
+#include <linux/in.h>
+#include <linux/unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+static const int PORT = 8888;
+
+static void build_rcv_fd(int family, int proto, int *rcv_fds, int count)
+{
+ struct sockaddr_storage addr;
+ struct sockaddr_in *addr4;
+ struct sockaddr_in6 *addr6;
+ int opt, i;
+
+ switch (family) {
+ case AF_INET:
+ addr4 = (struct sockaddr_in *)&addr;
+ addr4->sin_family = AF_INET;
+ addr4->sin_addr.s_addr = htonl(INADDR_ANY);
+ addr4->sin_port = htons(PORT);
+ break;
+ case AF_INET6:
+ addr6 = (struct sockaddr_in6 *)&addr;
+ addr6->sin6_family = AF_INET6;
+ addr6->sin6_addr = in6addr_any;
+ addr6->sin6_port = htons(PORT);
+ break;
+ default:
+ error(1, 0, "Unsupported family %d", family);
+ }
+
+ for (i = 0; i < count; ++i) {
+ rcv_fds[i] = socket(family, proto, 0);
+ if (rcv_fds[i] < 0)
+ error(1, errno, "failed to create receive socket");
+
+ opt = 1;
+ if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt,
+ sizeof(opt)))
+ error(1, errno, "failed to set SO_REUSEPORT");
+
+ if (bind(rcv_fds[i], (struct sockaddr *)&addr, sizeof(addr)))
+ error(1, errno, "failed to bind receive socket");
+
+ if (proto == SOCK_STREAM && listen(rcv_fds[i], 10))
+ error(1, errno, "failed to listen on receive port");
+ }
+}
+
+static void send_from_v4(int proto)
+{
+ struct sockaddr_in saddr, daddr;
+ int fd;
+
+ saddr.sin_family = AF_INET;
+ saddr.sin_addr.s_addr = htonl(INADDR_ANY);
+ saddr.sin_port = 0;
+
+ daddr.sin_family = AF_INET;
+ daddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ daddr.sin_port = htons(PORT);
+
+ fd = socket(AF_INET, proto, 0);
+ if (fd < 0)
+ error(1, errno, "failed to create send socket");
+
+ if (bind(fd, (struct sockaddr *)&saddr, sizeof(saddr)))
+ error(1, errno, "failed to bind send socket");
+
+ if (connect(fd, (struct sockaddr *)&daddr, sizeof(daddr)))
+ error(1, errno, "failed to connect send socket");
+
+ if (send(fd, "a", 1, 0) < 0)
+ error(1, errno, "failed to send message");
+
+ close(fd);
+}
+
+static int receive_once(int epfd, int proto)
+{
+ struct epoll_event ev;
+ int i, fd;
+ char buf[8];
+
+ i = epoll_wait(epfd, &ev, 1, -1);
+ if (i < 0)
+ error(1, errno, "epoll_wait failed");
+
+ if (proto == SOCK_STREAM) {
+ fd = accept(ev.data.fd, NULL, NULL);
+ if (fd < 0)
+ error(1, errno, "failed to accept");
+ i = recv(fd, buf, sizeof(buf), 0);
+ close(fd);
+ } else {
+ i = recv(ev.data.fd, buf, sizeof(buf), 0);
+ }
+
+ if (i < 0)
+ error(1, errno, "failed to recv");
+
+ return ev.data.fd;
+}
+
+static void test(int *rcv_fds, int count, int proto)
+{
+ struct epoll_event ev;
+ int epfd, i, test_fd;
+ uint16_t test_family;
+ socklen_t len;
+
+ epfd = epoll_create(1);
+ if (epfd < 0)
+ error(1, errno, "failed to create epoll");
+
+ ev.events = EPOLLIN;
+ for (i = 0; i < count; ++i) {
+ ev.data.fd = rcv_fds[i];
+ if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev))
+ error(1, errno, "failed to register sock epoll");
+ }
+
+ send_from_v4(proto);
+
+ test_fd = receive_once(epfd, proto);
+ if (getsockopt(test_fd, SOL_SOCKET, SO_DOMAIN, &test_family, &len))
+ error(1, errno, "failed to read socket domain");
+ if (test_family != AF_INET)
+ error(1, 0, "expected to receive on v4 socket but got v6 (%d)",
+ test_family);
+
+ close(epfd);
+}
+
+int main(void)
+{
+ int rcv_fds[32], i;
+
+ fprintf(stderr, "---- UDP IPv4 created before IPv6 ----\n");
+ build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds, 5);
+ build_rcv_fd(AF_INET6, SOCK_DGRAM, &(rcv_fds[5]), 5);
+ test(rcv_fds, 10, SOCK_DGRAM);
+ for (i = 0; i < 10; ++i)
+ close(rcv_fds[i]);
+
+ fprintf(stderr, "---- UDP IPv6 created before IPv4 ----\n");
+ build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds, 5);
+ build_rcv_fd(AF_INET, SOCK_DGRAM, &(rcv_fds[5]), 5);
+ test(rcv_fds, 10, SOCK_DGRAM);
+ for (i = 0; i < 10; ++i)
+ close(rcv_fds[i]);
+
+ /* NOTE: UDP socket lookups traverse a different code path when there
+ * are > 10 sockets in a group.
+ */
+ fprintf(stderr, "---- UDP IPv4 created before IPv6 (large) ----\n");
+ build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds, 16);
+ build_rcv_fd(AF_INET6, SOCK_DGRAM, &(rcv_fds[16]), 16);
+ test(rcv_fds, 32, SOCK_DGRAM);
+ for (i = 0; i < 32; ++i)
+ close(rcv_fds[i]);
+
+ fprintf(stderr, "---- UDP IPv6 created before IPv4 (large) ----\n");
+ build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds, 16);
+ build_rcv_fd(AF_INET, SOCK_DGRAM, &(rcv_fds[16]), 16);
+ test(rcv_fds, 32, SOCK_DGRAM);
+ for (i = 0; i < 32; ++i)
+ close(rcv_fds[i]);
+
+ fprintf(stderr, "---- TCP IPv4 created before IPv6 ----\n");
+ build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds, 5);
+ build_rcv_fd(AF_INET6, SOCK_STREAM, &(rcv_fds[5]), 5);
+ test(rcv_fds, 10, SOCK_STREAM);
+ for (i = 0; i < 10; ++i)
+ close(rcv_fds[i]);
+
+ fprintf(stderr, "---- TCP IPv6 created before IPv4 ----\n");
+ build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds, 5);
+ build_rcv_fd(AF_INET, SOCK_STREAM, &(rcv_fds[5]), 5);
+ test(rcv_fds, 10, SOCK_STREAM);
+ for (i = 0; i < 10; ++i)
+ close(rcv_fds[i]);
+
+ fprintf(stderr, "SUCCESS\n");
+ return 0;
+}
projects / cascardo / linux.git / commitdiff