--- /dev/null
+/*
+ * Test functionality of BPF filters for SO_REUSEPORT. The tests below will use
+ * a BPF program (both classic and extended) to read the first word from an
+ * incoming packet (expected to be in network byte-order), calculate a modulus
+ * of that number, and then dispatch the packet to the Nth socket using the
+ * result. These tests are run for each supported address family and protocol.
+ * Additionally, a few edge cases in the implementation are tested.
+ */
+
+#include <errno.h>
+#include <error.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/unistd.h>
+#include <netinet/in.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>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+#endif
+
+struct test_params {
+ int recv_family;
+ int send_family;
+ int protocol;
+ size_t recv_socks;
+ uint16_t recv_port;
+ uint16_t send_port_min;
+};
+
+static size_t sockaddr_size(void)
+{
+ return sizeof(struct sockaddr_storage);
+}
+
+static struct sockaddr *new_any_sockaddr(int family, uint16_t port)
+{
+ struct sockaddr_storage *addr;
+ struct sockaddr_in *addr4;
+ struct sockaddr_in6 *addr6;
+
+ addr = malloc(sizeof(struct sockaddr_storage));
+ memset(addr, 0, sizeof(struct sockaddr_storage));
+
+ 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);
+ }
+ return (struct sockaddr *)addr;
+}
+
+static struct sockaddr *new_loopback_sockaddr(int family, uint16_t port)
+{
+ struct sockaddr *addr = new_any_sockaddr(family, port);
+ struct sockaddr_in *addr4;
+ struct sockaddr_in6 *addr6;
+
+ switch (family) {
+ case AF_INET:
+ addr4 = (struct sockaddr_in *)addr;
+ addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ break;
+ case AF_INET6:
+ addr6 = (struct sockaddr_in6 *)addr;
+ addr6->sin6_addr = in6addr_loopback;
+ break;
+ default:
+ error(1, 0, "Unsupported family %d", family);
+ }
+ return addr;
+}
+
+static void attach_ebpf(int fd, uint16_t mod)
+{
+ static char bpf_log_buf[65536];
+ static const char bpf_license[] = "GPL";
+
+ int bpf_fd;
+ const struct bpf_insn prog[] = {
+ /* BPF_MOV64_REG(BPF_REG_6, BPF_REG_1) */
+ { BPF_ALU64 | BPF_MOV | BPF_X, BPF_REG_6, BPF_REG_1, 0, 0 },
+ /* BPF_LD_ABS(BPF_W, 0) R0 = (uint32_t)skb[0] */
+ { BPF_LD | BPF_ABS | BPF_W, 0, 0, 0, 0 },
+ /* BPF_ALU64_IMM(BPF_MOD, BPF_REG_0, mod) */
+ { BPF_ALU64 | BPF_MOD | BPF_K, BPF_REG_0, 0, 0, mod },
+ /* BPF_EXIT_INSN() */
+ { BPF_JMP | BPF_EXIT, 0, 0, 0, 0 }
+ };
+ union bpf_attr attr;
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ attr.insn_cnt = ARRAY_SIZE(prog);
+ attr.insns = (uint64_t)prog;
+ attr.license = (uint64_t)bpf_license;
+ attr.log_buf = (uint64_t)bpf_log_buf;
+ attr.log_size = sizeof(bpf_log_buf);
+ attr.log_level = 1;
+ attr.kern_version = 0;
+
+ bpf_fd = syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
+ if (bpf_fd < 0)
+ error(1, errno, "ebpf error. log:\n%s\n", bpf_log_buf);
+
+ if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &bpf_fd,
+ sizeof(bpf_fd)))
+ error(1, errno, "failed to set SO_ATTACH_REUSEPORT_EBPF");
+}
+
+static void attach_cbpf(int fd, uint16_t mod)
+{
+ struct sock_filter code[] = {
+ /* A = (uint32_t)skb[0] */
+ { BPF_LD | BPF_W | BPF_ABS, 0, 0, 0 },
+ /* A = A % mod */
+ { BPF_ALU | BPF_MOD, 0, 0, mod },
+ /* return A */
+ { BPF_RET | BPF_A, 0, 0, 0 },
+ };
+ struct sock_fprog p = {
+ .len = ARRAY_SIZE(code),
+ .filter = code,
+ };
+
+ if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_CBPF, &p, sizeof(p)))
+ error(1, errno, "failed to set SO_ATTACH_REUSEPORT_CBPF");
+}
+
+static void build_recv_group(const struct test_params p, int fd[], uint16_t mod,
+ void (*attach_bpf)(int, uint16_t))
+{
+ struct sockaddr * const addr =
+ new_any_sockaddr(p.recv_family, p.recv_port);
+ int i, opt;
+
+ for (i = 0; i < p.recv_socks; ++i) {
+ fd[i] = socket(p.recv_family, p.protocol, 0);
+ if (fd[i] < 0)
+ error(1, errno, "failed to create recv %d", i);
+
+ opt = 1;
+ if (setsockopt(fd[i], SOL_SOCKET, SO_REUSEPORT, &opt,
+ sizeof(opt)))
+ error(1, errno, "failed to set SO_REUSEPORT on %d", i);
+
+ if (i == 0)
+ attach_bpf(fd[i], mod);
+
+ if (bind(fd[i], addr, sockaddr_size()))
+ error(1, errno, "failed to bind recv socket %d", i);
+
+ if (p.protocol == SOCK_STREAM)
+ if (listen(fd[i], p.recv_socks * 10))
+ error(1, errno, "failed to listen on socket");
+ }
+ free(addr);
+}
+
+static void send_from(struct test_params p, uint16_t sport, char *buf,
+ size_t len)
+{
+ struct sockaddr * const saddr = new_any_sockaddr(p.send_family, sport);
+ struct sockaddr * const daddr =
+ new_loopback_sockaddr(p.send_family, p.recv_port);
+ const int fd = socket(p.send_family, p.protocol, 0);
+
+ if (fd < 0)
+ error(1, errno, "failed to create send socket");
+
+ if (bind(fd, saddr, sockaddr_size()))
+ error(1, errno, "failed to bind send socket");
+ if (connect(fd, daddr, sockaddr_size()))
+ error(1, errno, "failed to connect");
+
+ if (send(fd, buf, len, 0) < 0)
+ error(1, errno, "failed to send message");
+
+ close(fd);
+ free(saddr);
+ free(daddr);
+}
+
+static void test_recv_order(const struct test_params p, int fd[], int mod)
+{
+ char recv_buf[8], send_buf[8];
+ struct msghdr msg;
+ struct iovec recv_io = { recv_buf, 8 };
+ struct epoll_event ev;
+ int epfd, conn, i, sport, expected;
+ uint32_t data, ndata;
+
+ epfd = epoll_create(1);
+ if (epfd < 0)
+ error(1, errno, "failed to create epoll");
+ for (i = 0; i < p.recv_socks; ++i) {
+ ev.events = EPOLLIN;
+ ev.data.fd = fd[i];
+ if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd[i], &ev))
+ error(1, errno, "failed to register sock %d epoll", i);
+ }
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_iov = &recv_io;
+ msg.msg_iovlen = 1;
+
+ for (data = 0; data < p.recv_socks * 2; ++data) {
+ sport = p.send_port_min + data;
+ ndata = htonl(data);
+ memcpy(send_buf, &ndata, sizeof(ndata));
+ send_from(p, sport, send_buf, sizeof(ndata));
+
+ i = epoll_wait(epfd, &ev, 1, -1);
+ if (i < 0)
+ error(1, errno, "epoll wait failed");
+
+ if (p.protocol == SOCK_STREAM) {
+ conn = accept(ev.data.fd, NULL, NULL);
+ if (conn < 0)
+ error(1, errno, "error accepting");
+ i = recvmsg(conn, &msg, 0);
+ close(conn);
+ } else {
+ i = recvmsg(ev.data.fd, &msg, 0);
+ }
+ if (i < 0)
+ error(1, errno, "recvmsg error");
+ if (i != sizeof(ndata))
+ error(1, 0, "expected size %zd got %d",
+ sizeof(ndata), i);
+
+ for (i = 0; i < p.recv_socks; ++i)
+ if (ev.data.fd == fd[i])
+ break;
+ memcpy(&ndata, recv_buf, sizeof(ndata));
+ fprintf(stderr, "Socket %d: %d\n", i, ntohl(ndata));
+
+ expected = (sport % mod);
+ if (i != expected)
+ error(1, 0, "expected socket %d", expected);
+ }
+}
+
+static void test_reuseport_ebpf(const struct test_params p)
+{
+ int i, fd[p.recv_socks];
+
+ fprintf(stderr, "Testing EBPF mod %zd...\n", p.recv_socks);
+ build_recv_group(p, fd, p.recv_socks, attach_ebpf);
+ test_recv_order(p, fd, p.recv_socks);
+
+ fprintf(stderr, "Reprograming, testing mod %zd...\n", p.recv_socks / 2);
+ attach_ebpf(fd[0], p.recv_socks / 2);
+ test_recv_order(p, fd, p.recv_socks / 2);
+
+ for (i = 0; i < p.recv_socks; ++i)
+ close(fd[i]);
+}
+
+static void test_reuseport_cbpf(const struct test_params p)
+{
+ int i, fd[p.recv_socks];
+
+ fprintf(stderr, "Testing CBPF mod %zd...\n", p.recv_socks);
+ build_recv_group(p, fd, p.recv_socks, attach_cbpf);
+ test_recv_order(p, fd, p.recv_socks);
+
+ fprintf(stderr, "Reprograming, testing mod %zd...\n", p.recv_socks / 2);
+ attach_cbpf(fd[0], p.recv_socks / 2);
+ test_recv_order(p, fd, p.recv_socks / 2);
+
+ for (i = 0; i < p.recv_socks; ++i)
+ close(fd[i]);
+}
+
+static void test_extra_filter(const struct test_params p)
+{
+ struct sockaddr * const addr =
+ new_any_sockaddr(p.recv_family, p.recv_port);
+ int fd1, fd2, opt;
+
+ fprintf(stderr, "Testing too many filters...\n");
+ fd1 = socket(p.recv_family, p.protocol, 0);
+ if (fd1 < 0)
+ error(1, errno, "failed to create socket 1");
+ fd2 = socket(p.recv_family, p.protocol, 0);
+ if (fd2 < 0)
+ error(1, errno, "failed to create socket 2");
+
+ opt = 1;
+ if (setsockopt(fd1, SOL_SOCKET, SO_REUSEPORT, &opt, sizeof(opt)))
+ error(1, errno, "failed to set SO_REUSEPORT on socket 1");
+ if (setsockopt(fd2, SOL_SOCKET, SO_REUSEPORT, &opt, sizeof(opt)))
+ error(1, errno, "failed to set SO_REUSEPORT on socket 2");
+
+ attach_ebpf(fd1, 10);
+ attach_ebpf(fd2, 10);
+
+ if (bind(fd1, addr, sockaddr_size()))
+ error(1, errno, "failed to bind recv socket 1");
+
+ if (!bind(fd2, addr, sockaddr_size()) && errno != EADDRINUSE)
+ error(1, errno, "bind socket 2 should fail with EADDRINUSE");
+
+ free(addr);
+}
+
+static void test_filter_no_reuseport(const struct test_params p)
+{
+ struct sockaddr * const addr =
+ new_any_sockaddr(p.recv_family, p.recv_port);
+ const char bpf_license[] = "GPL";
+ struct bpf_insn ecode[] = {
+ { BPF_ALU64 | BPF_MOV | BPF_K, BPF_REG_0, 0, 0, 10 },
+ { BPF_JMP | BPF_EXIT, 0, 0, 0, 0 }
+ };
+ struct sock_filter ccode[] = {{ BPF_RET | BPF_A, 0, 0, 0 }};
+ union bpf_attr eprog;
+ struct sock_fprog cprog;
+ int fd, bpf_fd;
+
+ fprintf(stderr, "Testing filters on non-SO_REUSEPORT socket...\n");
+
+ memset(&eprog, 0, sizeof(eprog));
+ eprog.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ eprog.insn_cnt = ARRAY_SIZE(ecode);
+ eprog.insns = (uint64_t)ecode;
+ eprog.license = (uint64_t)bpf_license;
+ eprog.kern_version = 0;
+
+ memset(&cprog, 0, sizeof(cprog));
+ cprog.len = ARRAY_SIZE(ccode);
+ cprog.filter = ccode;
+
+
+ bpf_fd = syscall(__NR_bpf, BPF_PROG_LOAD, &eprog, sizeof(eprog));
+ if (bpf_fd < 0)
+ error(1, errno, "ebpf error");
+ fd = socket(p.recv_family, p.protocol, 0);
+ if (fd < 0)
+ error(1, errno, "failed to create socket 1");
+
+ if (bind(fd, addr, sockaddr_size()))
+ error(1, errno, "failed to bind recv socket 1");
+
+ errno = 0;
+ if (!setsockopt(fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &bpf_fd,
+ sizeof(bpf_fd)) || errno != EINVAL)
+ error(1, errno, "setsockopt should have returned EINVAL");
+
+ errno = 0;
+ if (!setsockopt(fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_CBPF, &cprog,
+ sizeof(cprog)) || errno != EINVAL)
+ error(1, errno, "setsockopt should have returned EINVAL");
+
+ free(addr);
+}
+
+static void test_filter_without_bind(void)
+{
+ int fd1, fd2;
+
+ fprintf(stderr, "Testing filter add without bind...\n");
+ fd1 = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd1 < 0)
+ error(1, errno, "failed to create socket 1");
+ fd2 = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd2 < 0)
+ error(1, errno, "failed to create socket 2");
+
+ attach_ebpf(fd1, 10);
+ attach_cbpf(fd2, 10);
+
+ close(fd1);
+ close(fd2);
+}
+
+
+int main(void)
+{
+ fprintf(stderr, "---- IPv4 UDP ----\n");
+ test_reuseport_ebpf((struct test_params) {
+ .recv_family = AF_INET,
+ .send_family = AF_INET,
+ .protocol = SOCK_DGRAM,
+ .recv_socks = 10,
+ .recv_port = 8000,
+ .send_port_min = 9000});
+ test_reuseport_cbpf((struct test_params) {
+ .recv_family = AF_INET,
+ .send_family = AF_INET,
+ .protocol = SOCK_DGRAM,
+ .recv_socks = 10,
+ .recv_port = 8001,
+ .send_port_min = 9020});
+ test_extra_filter((struct test_params) {
+ .recv_family = AF_INET,
+ .protocol = SOCK_DGRAM,
+ .recv_port = 8002});
+ test_filter_no_reuseport((struct test_params) {
+ .recv_family = AF_INET,
+ .protocol = SOCK_DGRAM,
+ .recv_port = 8008});
+
+ fprintf(stderr, "---- IPv6 UDP ----\n");
+ test_reuseport_ebpf((struct test_params) {
+ .recv_family = AF_INET6,
+ .send_family = AF_INET6,
+ .protocol = SOCK_DGRAM,
+ .recv_socks = 10,
+ .recv_port = 8003,
+ .send_port_min = 9040});
+ test_reuseport_cbpf((struct test_params) {
+ .recv_family = AF_INET6,
+ .send_family = AF_INET6,
+ .protocol = SOCK_DGRAM,
+ .recv_socks = 10,
+ .recv_port = 8004,
+ .send_port_min = 9060});
+ test_extra_filter((struct test_params) {
+ .recv_family = AF_INET6,
+ .protocol = SOCK_DGRAM,
+ .recv_port = 8005});
+ test_filter_no_reuseport((struct test_params) {
+ .recv_family = AF_INET6,
+ .protocol = SOCK_DGRAM,
+ .recv_port = 8009});
+
+ fprintf(stderr, "---- IPv6 UDP w/ mapped IPv4 ----\n");
+ test_reuseport_ebpf((struct test_params) {
+ .recv_family = AF_INET6,
+ .send_family = AF_INET,
+ .protocol = SOCK_DGRAM,
+ .recv_socks = 10,
+ .recv_port = 8006,
+ .send_port_min = 9080});
+ test_reuseport_cbpf((struct test_params) {
+ .recv_family = AF_INET6,
+ .send_family = AF_INET,
+ .protocol = SOCK_DGRAM,
+ .recv_socks = 10,
+ .recv_port = 8007,
+ .send_port_min = 9100});
+
+
+ test_filter_without_bind();
+
+ fprintf(stderr, "SUCCESS\n");
+ return 0;
+}
projects / cascardo / linux.git / commitdiff