// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Facebook
+#define _GNU_SOURCE
+
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
+#include <netinet/in.h>
#include <sys/types.h>
+#include <sys/select.h>
#include <sys/socket.h>
#include <linux/filter.h>
#include "cgroup_helpers.h"
#include "bpf_rlimit.h"
+#ifndef ENOTSUPP
+# define ENOTSUPP 524
+#endif
+
#ifndef ARRAY_SIZE
# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif
#define CG_PATH "/foo"
#define CONNECT4_PROG_PATH "./connect4_prog.o"
#define CONNECT6_PROG_PATH "./connect6_prog.o"
+#define SENDMSG4_PROG_PATH "./sendmsg4_prog.o"
+#define SENDMSG6_PROG_PATH "./sendmsg6_prog.o"
#define SERV4_IP "192.168.1.254"
#define SERV4_REWRITE_IP "127.0.0.1"
+#define SRC4_IP "172.16.0.1"
#define SRC4_REWRITE_IP "127.0.0.4"
#define SERV4_PORT 4040
#define SERV4_REWRITE_PORT 4444
#define SERV6_IP "face:b00c:1234:5678::abcd"
#define SERV6_REWRITE_IP "::1"
+#define SERV6_V4MAPPED_IP "::ffff:192.168.0.4"
+#define SRC6_IP "::1"
#define SRC6_REWRITE_IP "::6"
#define SERV6_PORT 6060
#define SERV6_REWRITE_PORT 6666
enum {
LOAD_REJECT,
ATTACH_REJECT,
+ SYSCALL_EPERM,
+ SYSCALL_ENOTSUPP,
SUCCESS,
} expected_result;
};
static int bind6_prog_load(const struct sock_addr_test *test);
static int connect4_prog_load(const struct sock_addr_test *test);
static int connect6_prog_load(const struct sock_addr_test *test);
+static int sendmsg_deny_prog_load(const struct sock_addr_test *test);
+static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test);
+static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test);
+static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test);
+static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test);
+static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test);
static struct sock_addr_test tests[] = {
/* bind */
SRC6_REWRITE_IP,
SUCCESS,
},
+
+ /* sendmsg */
+ {
+ "sendmsg4: load prog with wrong expected attach type",
+ sendmsg4_rw_asm_prog_load,
+ BPF_CGROUP_UDP6_SENDMSG,
+ BPF_CGROUP_UDP4_SENDMSG,
+ AF_INET,
+ SOCK_DGRAM,
+ NULL,
+ 0,
+ NULL,
+ 0,
+ NULL,
+ LOAD_REJECT,
+ },
+ {
+ "sendmsg4: attach prog with wrong attach type",
+ sendmsg4_rw_asm_prog_load,
+ BPF_CGROUP_UDP4_SENDMSG,
+ BPF_CGROUP_UDP6_SENDMSG,
+ AF_INET,
+ SOCK_DGRAM,
+ NULL,
+ 0,
+ NULL,
+ 0,
+ NULL,
+ ATTACH_REJECT,
+ },
+ {
+ "sendmsg4: rewrite IP & port (asm)",
+ sendmsg4_rw_asm_prog_load,
+ BPF_CGROUP_UDP4_SENDMSG,
+ BPF_CGROUP_UDP4_SENDMSG,
+ AF_INET,
+ SOCK_DGRAM,
+ SERV4_IP,
+ SERV4_PORT,
+ SERV4_REWRITE_IP,
+ SERV4_REWRITE_PORT,
+ SRC4_REWRITE_IP,
+ SUCCESS,
+ },
+ {
+ "sendmsg4: rewrite IP & port (C)",
+ sendmsg4_rw_c_prog_load,
+ BPF_CGROUP_UDP4_SENDMSG,
+ BPF_CGROUP_UDP4_SENDMSG,
+ AF_INET,
+ SOCK_DGRAM,
+ SERV4_IP,
+ SERV4_PORT,
+ SERV4_REWRITE_IP,
+ SERV4_REWRITE_PORT,
+ SRC4_REWRITE_IP,
+ SUCCESS,
+ },
+ {
+ "sendmsg4: deny call",
+ sendmsg_deny_prog_load,
+ BPF_CGROUP_UDP4_SENDMSG,
+ BPF_CGROUP_UDP4_SENDMSG,
+ AF_INET,
+ SOCK_DGRAM,
+ SERV4_IP,
+ SERV4_PORT,
+ SERV4_REWRITE_IP,
+ SERV4_REWRITE_PORT,
+ SRC4_REWRITE_IP,
+ SYSCALL_EPERM,
+ },
+ {
+ "sendmsg6: load prog with wrong expected attach type",
+ sendmsg6_rw_asm_prog_load,
+ BPF_CGROUP_UDP4_SENDMSG,
+ BPF_CGROUP_UDP6_SENDMSG,
+ AF_INET6,
+ SOCK_DGRAM,
+ NULL,
+ 0,
+ NULL,
+ 0,
+ NULL,
+ LOAD_REJECT,
+ },
+ {
+ "sendmsg6: attach prog with wrong attach type",
+ sendmsg6_rw_asm_prog_load,
+ BPF_CGROUP_UDP6_SENDMSG,
+ BPF_CGROUP_UDP4_SENDMSG,
+ AF_INET6,
+ SOCK_DGRAM,
+ NULL,
+ 0,
+ NULL,
+ 0,
+ NULL,
+ ATTACH_REJECT,
+ },
+ {
+ "sendmsg6: rewrite IP & port (asm)",
+ sendmsg6_rw_asm_prog_load,
+ BPF_CGROUP_UDP6_SENDMSG,
+ BPF_CGROUP_UDP6_SENDMSG,
+ AF_INET6,
+ SOCK_DGRAM,
+ SERV6_IP,
+ SERV6_PORT,
+ SERV6_REWRITE_IP,
+ SERV6_REWRITE_PORT,
+ SRC6_REWRITE_IP,
+ SUCCESS,
+ },
+ {
+ "sendmsg6: rewrite IP & port (C)",
+ sendmsg6_rw_c_prog_load,
+ BPF_CGROUP_UDP6_SENDMSG,
+ BPF_CGROUP_UDP6_SENDMSG,
+ AF_INET6,
+ SOCK_DGRAM,
+ SERV6_IP,
+ SERV6_PORT,
+ SERV6_REWRITE_IP,
+ SERV6_REWRITE_PORT,
+ SRC6_REWRITE_IP,
+ SUCCESS,
+ },
+ {
+ "sendmsg6: IPv4-mapped IPv6",
+ sendmsg6_rw_v4mapped_prog_load,
+ BPF_CGROUP_UDP6_SENDMSG,
+ BPF_CGROUP_UDP6_SENDMSG,
+ AF_INET6,
+ SOCK_DGRAM,
+ SERV6_IP,
+ SERV6_PORT,
+ SERV6_REWRITE_IP,
+ SERV6_REWRITE_PORT,
+ SRC6_REWRITE_IP,
+ SYSCALL_ENOTSUPP,
+ },
+ {
+ "sendmsg6: deny call",
+ sendmsg_deny_prog_load,
+ BPF_CGROUP_UDP6_SENDMSG,
+ BPF_CGROUP_UDP6_SENDMSG,
+ AF_INET6,
+ SOCK_DGRAM,
+ SERV6_IP,
+ SERV6_PORT,
+ SERV6_REWRITE_IP,
+ SERV6_REWRITE_PORT,
+ SRC6_REWRITE_IP,
+ SYSCALL_EPERM,
+ },
};
static int mk_sockaddr(int domain, const char *ip, unsigned short port,
return load_path(test, CONNECT6_PROG_PATH);
}
+static int sendmsg_deny_prog_load(const struct sock_addr_test *test)
+{
+ struct bpf_insn insns[] = {
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
+}
+
+static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test)
+{
+ struct sockaddr_in dst4_rw_addr;
+ struct in_addr src4_rw_ip;
+
+ if (inet_pton(AF_INET, SRC4_REWRITE_IP, (void *)&src4_rw_ip) != 1) {
+ log_err("Invalid IPv4: %s", SRC4_REWRITE_IP);
+ return -1;
+ }
+
+ if (mk_sockaddr(AF_INET, SERV4_REWRITE_IP, SERV4_REWRITE_PORT,
+ (struct sockaddr *)&dst4_rw_addr,
+ sizeof(dst4_rw_addr)) == -1)
+ return -1;
+
+ struct bpf_insn insns[] = {
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+
+ /* if (sk.family == AF_INET && */
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock_addr, family)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET, 8),
+
+ /* sk.type == SOCK_DGRAM) { */
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock_addr, type)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_DGRAM, 6),
+
+ /* msg_src_ip4 = src4_rw_ip */
+ BPF_MOV32_IMM(BPF_REG_7, src4_rw_ip.s_addr),
+ BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
+ offsetof(struct bpf_sock_addr, msg_src_ip4)),
+
+ /* user_ip4 = dst4_rw_addr.sin_addr */
+ BPF_MOV32_IMM(BPF_REG_7, dst4_rw_addr.sin_addr.s_addr),
+ BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
+ offsetof(struct bpf_sock_addr, user_ip4)),
+
+ /* user_port = dst4_rw_addr.sin_port */
+ BPF_MOV32_IMM(BPF_REG_7, dst4_rw_addr.sin_port),
+ BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
+ offsetof(struct bpf_sock_addr, user_port)),
+ /* } */
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ };
+
+ return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
+}
+
+static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test)
+{
+ return load_path(test, SENDMSG4_PROG_PATH);
+}
+
+static int sendmsg6_rw_dst_asm_prog_load(const struct sock_addr_test *test,
+ const char *rw_dst_ip)
+{
+ struct sockaddr_in6 dst6_rw_addr;
+ struct in6_addr src6_rw_ip;
+
+ if (inet_pton(AF_INET6, SRC6_REWRITE_IP, (void *)&src6_rw_ip) != 1) {
+ log_err("Invalid IPv6: %s", SRC6_REWRITE_IP);
+ return -1;
+ }
+
+ if (mk_sockaddr(AF_INET6, rw_dst_ip, SERV6_REWRITE_PORT,
+ (struct sockaddr *)&dst6_rw_addr,
+ sizeof(dst6_rw_addr)) == -1)
+ return -1;
+
+ struct bpf_insn insns[] = {
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+
+ /* if (sk.family == AF_INET6) { */
+ BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
+ offsetof(struct bpf_sock_addr, family)),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET6, 18),
+
+#define STORE_IPV6_WORD_N(DST, SRC, N) \
+ BPF_MOV32_IMM(BPF_REG_7, SRC[N]), \
+ BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, \
+ offsetof(struct bpf_sock_addr, DST[N]))
+
+#define STORE_IPV6(DST, SRC) \
+ STORE_IPV6_WORD_N(DST, SRC, 0), \
+ STORE_IPV6_WORD_N(DST, SRC, 1), \
+ STORE_IPV6_WORD_N(DST, SRC, 2), \
+ STORE_IPV6_WORD_N(DST, SRC, 3)
+
+ STORE_IPV6(msg_src_ip6, src6_rw_ip.s6_addr32),
+ STORE_IPV6(user_ip6, dst6_rw_addr.sin6_addr.s6_addr32),
+
+ /* user_port = dst6_rw_addr.sin6_port */
+ BPF_MOV32_IMM(BPF_REG_7, dst6_rw_addr.sin6_port),
+ BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
+ offsetof(struct bpf_sock_addr, user_port)),
+
+ /* } */
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ };
+
+ return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
+}
+
+static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test)
+{
+ return sendmsg6_rw_dst_asm_prog_load(test, SERV6_REWRITE_IP);
+}
+
+static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test)
+{
+ return sendmsg6_rw_dst_asm_prog_load(test, SERV6_V4MAPPED_IP);
+}
+
+static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test)
+{
+ return load_path(test, SENDMSG6_PROG_PATH);
+}
+
static int cmp_addr(const struct sockaddr_storage *addr1,
const struct sockaddr_storage *addr2, int cmp_port)
{
return fd;
}
+int init_pktinfo(int domain, struct cmsghdr *cmsg)
+{
+ struct in6_pktinfo *pktinfo6;
+ struct in_pktinfo *pktinfo4;
+
+ if (domain == AF_INET) {
+ cmsg->cmsg_level = SOL_IP;
+ cmsg->cmsg_type = IP_PKTINFO;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
+ pktinfo4 = (struct in_pktinfo *)CMSG_DATA(cmsg);
+ memset(pktinfo4, 0, sizeof(struct in_pktinfo));
+ if (inet_pton(domain, SRC4_IP,
+ (void *)&pktinfo4->ipi_spec_dst) != 1)
+ return -1;
+ } else if (domain == AF_INET6) {
+ cmsg->cmsg_level = SOL_IPV6;
+ cmsg->cmsg_type = IPV6_PKTINFO;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
+ pktinfo6 = (struct in6_pktinfo *)CMSG_DATA(cmsg);
+ memset(pktinfo6, 0, sizeof(struct in6_pktinfo));
+ if (inet_pton(domain, SRC6_IP,
+ (void *)&pktinfo6->ipi6_addr) != 1)
+ return -1;
+ } else {
+ return -1;
+ }
+
+ return 0;
+}
+
+static int sendmsg_to_server(const struct sockaddr_storage *addr,
+ socklen_t addr_len, int set_cmsg, int *syscall_err)
+{
+ union {
+ char buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
+ struct cmsghdr align;
+ } control6;
+ union {
+ char buf[CMSG_SPACE(sizeof(struct in_pktinfo))];
+ struct cmsghdr align;
+ } control4;
+ struct msghdr hdr;
+ struct iovec iov;
+ char data = 'a';
+ int domain;
+ int fd = -1;
+
+ domain = addr->ss_family;
+
+ if (domain != AF_INET && domain != AF_INET6) {
+ log_err("Unsupported address family");
+ goto err;
+ }
+
+ fd = socket(domain, SOCK_DGRAM, 0);
+ if (fd == -1) {
+ log_err("Failed to create client socket");
+ goto err;
+ }
+
+ memset(&iov, 0, sizeof(iov));
+ iov.iov_base = &data;
+ iov.iov_len = sizeof(data);
+
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.msg_name = (void *)addr;
+ hdr.msg_namelen = addr_len;
+ hdr.msg_iov = &iov;
+ hdr.msg_iovlen = 1;
+
+ if (set_cmsg) {
+ if (domain == AF_INET) {
+ hdr.msg_control = &control4;
+ hdr.msg_controllen = sizeof(control4.buf);
+ } else if (domain == AF_INET6) {
+ hdr.msg_control = &control6;
+ hdr.msg_controllen = sizeof(control6.buf);
+ }
+ if (init_pktinfo(domain, CMSG_FIRSTHDR(&hdr))) {
+ log_err("Fail to init pktinfo");
+ goto err;
+ }
+ }
+
+ if (sendmsg(fd, &hdr, 0) != sizeof(data)) {
+ log_err("Fail to send message to server");
+ *syscall_err = errno;
+ goto err;
+ }
+
+ goto out;
+err:
+ close(fd);
+ fd = -1;
+out:
+ return fd;
+}
+
+static int recvmsg_from_client(int sockfd, struct sockaddr_storage *src_addr)
+{
+ struct timeval tv;
+ struct msghdr hdr;
+ struct iovec iov;
+ char data[64];
+ fd_set rfds;
+
+ FD_ZERO(&rfds);
+ FD_SET(sockfd, &rfds);
+
+ tv.tv_sec = 2;
+ tv.tv_usec = 0;
+
+ if (select(sockfd + 1, &rfds, NULL, NULL, &tv) <= 0 ||
+ !FD_ISSET(sockfd, &rfds))
+ return -1;
+
+ memset(&iov, 0, sizeof(iov));
+ iov.iov_base = data;
+ iov.iov_len = sizeof(data);
+
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.msg_name = src_addr;
+ hdr.msg_namelen = sizeof(struct sockaddr_storage);
+ hdr.msg_iov = &iov;
+ hdr.msg_iovlen = 1;
+
+ return recvmsg(sockfd, &hdr, 0);
+}
+
static int init_addrs(const struct sock_addr_test *test,
struct sockaddr_storage *requested_addr,
struct sockaddr_storage *expected_addr,
return err;
}
+static int run_sendmsg_test_case(const struct sock_addr_test *test)
+{
+ socklen_t addr_len = sizeof(struct sockaddr_storage);
+ struct sockaddr_storage expected_src_addr;
+ struct sockaddr_storage requested_addr;
+ struct sockaddr_storage expected_addr;
+ struct sockaddr_storage real_src_addr;
+ int clientfd = -1;
+ int servfd = -1;
+ int set_cmsg;
+ int err = 0;
+
+ if (test->type != SOCK_DGRAM)
+ goto err;
+
+ if (init_addrs(test, &requested_addr, &expected_addr,
+ &expected_src_addr))
+ goto err;
+
+ /* Prepare server to sendmsg to */
+ servfd = start_server(test->type, &expected_addr, addr_len);
+ if (servfd == -1)
+ goto err;
+
+ for (set_cmsg = 0; set_cmsg <= 1; ++set_cmsg) {
+ if (clientfd >= 0)
+ close(clientfd);
+
+ clientfd = sendmsg_to_server(&requested_addr, addr_len,
+ set_cmsg, &err);
+ if (err)
+ goto out;
+ else if (clientfd == -1)
+ goto err;
+
+ /* Try to receive message on server instead of using
+ * getpeername(2) on client socket, to check that client's
+ * destination address was rewritten properly, since
+ * getpeername(2) doesn't work with unconnected datagram
+ * sockets.
+ *
+ * Get source address from recvmsg(2) as well to make sure
+ * source was rewritten properly: getsockname(2) can't be used
+ * since socket is unconnected and source defined for one
+ * specific packet may differ from the one used by default and
+ * returned by getsockname(2).
+ */
+ if (recvmsg_from_client(servfd, &real_src_addr) == -1)
+ goto err;
+
+ if (cmp_addr(&real_src_addr, &expected_src_addr, /*cmp_port*/0))
+ goto err;
+ }
+
+ goto out;
+err:
+ err = -1;
+out:
+ close(clientfd);
+ close(servfd);
+ return err;
+}
+
static int run_test_case(int cgfd, const struct sock_addr_test *test)
{
int progfd = -1;
case BPF_CGROUP_INET6_CONNECT:
err = run_connect_test_case(test);
break;
+ case BPF_CGROUP_UDP4_SENDMSG:
+ case BPF_CGROUP_UDP6_SENDMSG:
+ err = run_sendmsg_test_case(test);
+ break;
default:
goto err;
}
+ if (test->expected_result == SYSCALL_EPERM && err == EPERM) {
+ err = 0; /* error was expected, reset it */
+ goto out;
+ }
+
+ if (test->expected_result == SYSCALL_ENOTSUPP && err == ENOTSUPP) {
+ err = 0; /* error was expected, reset it */
+ goto out;
+ }
+
if (err || test->expected_result != SUCCESS)
goto err;