/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __SOCKET_HELPERS__ #define __SOCKET_HELPERS__ #include /* include/linux/net.h */ #define SOCK_TYPE_MASK 0xf #define IO_TIMEOUT_SEC 30 #define MAX_STRERR_LEN 256 /* workaround for older vm_sockets.h */ #ifndef VMADDR_CID_LOCAL #define VMADDR_CID_LOCAL 1 #endif /* include/linux/cleanup.h */ #define __get_and_null(p, nullvalue) \ ({ \ __auto_type __ptr = &(p); \ __auto_type __val = *__ptr; \ *__ptr = nullvalue; \ __val; \ }) #define take_fd(fd) __get_and_null(fd, -EBADF) /* Wrappers that fail the test on error and report it. */ #define _FAIL(errnum, fmt...) \ ({ \ error_at_line(0, (errnum), __func__, __LINE__, fmt); \ CHECK_FAIL(true); \ }) #define FAIL(fmt...) _FAIL(0, fmt) #define FAIL_ERRNO(fmt...) _FAIL(errno, fmt) #define FAIL_LIBBPF(err, msg) \ ({ \ char __buf[MAX_STRERR_LEN]; \ libbpf_strerror((err), __buf, sizeof(__buf)); \ FAIL("%s: %s", (msg), __buf); \ }) #define xaccept_nonblock(fd, addr, len) \ ({ \ int __ret = \ accept_timeout((fd), (addr), (len), IO_TIMEOUT_SEC); \ if (__ret == -1) \ FAIL_ERRNO("accept"); \ __ret; \ }) #define xbind(fd, addr, len) \ ({ \ int __ret = bind((fd), (addr), (len)); \ if (__ret == -1) \ FAIL_ERRNO("bind"); \ __ret; \ }) #define xclose(fd) \ ({ \ int __ret = close((fd)); \ if (__ret == -1) \ FAIL_ERRNO("close"); \ __ret; \ }) #define xconnect(fd, addr, len) \ ({ \ int __ret = connect((fd), (addr), (len)); \ if (__ret == -1) \ FAIL_ERRNO("connect"); \ __ret; \ }) #define xgetsockname(fd, addr, len) \ ({ \ int __ret = getsockname((fd), (addr), (len)); \ if (__ret == -1) \ FAIL_ERRNO("getsockname"); \ __ret; \ }) #define xgetsockopt(fd, level, name, val, len) \ ({ \ int __ret = getsockopt((fd), (level), (name), (val), (len)); \ if (__ret == -1) \ FAIL_ERRNO("getsockopt(" #name ")"); \ __ret; \ }) #define xlisten(fd, backlog) \ ({ \ int __ret = listen((fd), (backlog)); \ if (__ret == -1) \ FAIL_ERRNO("listen"); \ __ret; \ }) #define xsetsockopt(fd, level, name, val, len) \ ({ \ int __ret = setsockopt((fd), (level), (name), (val), (len)); \ if (__ret == -1) \ FAIL_ERRNO("setsockopt(" #name ")"); \ __ret; \ }) #define xsend(fd, buf, len, flags) \ ({ \ ssize_t __ret = send((fd), (buf), (len), (flags)); \ if (__ret == -1) \ FAIL_ERRNO("send"); \ __ret; \ }) #define xrecv_nonblock(fd, buf, len, flags) \ ({ \ ssize_t __ret = recv_timeout((fd), (buf), (len), (flags), \ IO_TIMEOUT_SEC); \ if (__ret == -1) \ FAIL_ERRNO("recv"); \ __ret; \ }) #define xsocket(family, sotype, flags) \ ({ \ int __ret = socket(family, sotype, flags); \ if (__ret == -1) \ FAIL_ERRNO("socket"); \ __ret; \ }) static inline void close_fd(int *fd) { if (*fd >= 0) xclose(*fd); } #define __close_fd __attribute__((cleanup(close_fd))) static inline struct sockaddr *sockaddr(struct sockaddr_storage *ss) { return (struct sockaddr *)ss; } static inline void init_addr_loopback4(struct sockaddr_storage *ss, socklen_t *len) { struct sockaddr_in *addr4 = memset(ss, 0, sizeof(*ss)); addr4->sin_family = AF_INET; addr4->sin_port = 0; addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK); *len = sizeof(*addr4); } static inline void init_addr_loopback6(struct sockaddr_storage *ss, socklen_t *len) { struct sockaddr_in6 *addr6 = memset(ss, 0, sizeof(*ss)); addr6->sin6_family = AF_INET6; addr6->sin6_port = 0; addr6->sin6_addr = in6addr_loopback; *len = sizeof(*addr6); } static inline void init_addr_loopback_vsock(struct sockaddr_storage *ss, socklen_t *len) { struct sockaddr_vm *addr = memset(ss, 0, sizeof(*ss)); addr->svm_family = AF_VSOCK; addr->svm_port = VMADDR_PORT_ANY; addr->svm_cid = VMADDR_CID_LOCAL; *len = sizeof(*addr); } static inline void init_addr_loopback(int family, struct sockaddr_storage *ss, socklen_t *len) { switch (family) { case AF_INET: init_addr_loopback4(ss, len); return; case AF_INET6: init_addr_loopback6(ss, len); return; case AF_VSOCK: init_addr_loopback_vsock(ss, len); return; default: FAIL("unsupported address family %d", family); } } static inline int enable_reuseport(int s, int progfd) { int err, one = 1; err = xsetsockopt(s, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)); if (err) return -1; err = xsetsockopt(s, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &progfd, sizeof(progfd)); if (err) return -1; return 0; } static inline int socket_loopback_reuseport(int family, int sotype, int progfd) { struct sockaddr_storage addr; socklen_t len = 0; int err, s; init_addr_loopback(family, &addr, &len); s = xsocket(family, sotype, 0); if (s == -1) return -1; if (progfd >= 0) enable_reuseport(s, progfd); err = xbind(s, sockaddr(&addr), len); if (err) goto close; if (sotype & SOCK_DGRAM) return s; err = xlisten(s, SOMAXCONN); if (err) goto close; return s; close: xclose(s); return -1; } static inline int socket_loopback(int family, int sotype) { return socket_loopback_reuseport(family, sotype, -1); } static inline int poll_connect(int fd, unsigned int timeout_sec) { struct timeval timeout = { .tv_sec = timeout_sec }; fd_set wfds; int r, eval; socklen_t esize = sizeof(eval); FD_ZERO(&wfds); FD_SET(fd, &wfds); r = select(fd + 1, NULL, &wfds, NULL, &timeout); if (r == 0) errno = ETIME; if (r != 1) return -1; if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &eval, &esize) < 0) return -1; if (eval != 0) { errno = eval; return -1; } return 0; } static inline int poll_read(int fd, unsigned int timeout_sec) { struct timeval timeout = { .tv_sec = timeout_sec }; fd_set rfds; int r; FD_ZERO(&rfds); FD_SET(fd, &rfds); r = select(fd + 1, &rfds, NULL, NULL, &timeout); if (r == 0) errno = ETIME; return r == 1 ? 0 : -1; } static inline int accept_timeout(int fd, struct sockaddr *addr, socklen_t *len, unsigned int timeout_sec) { if (poll_read(fd, timeout_sec)) return -1; return accept(fd, addr, len); } static inline int recv_timeout(int fd, void *buf, size_t len, int flags, unsigned int timeout_sec) { if (poll_read(fd, timeout_sec)) return -1; return recv(fd, buf, len, flags); } static inline int create_pair(int family, int sotype, int *p0, int *p1) { __close_fd int s, c = -1, p = -1; struct sockaddr_storage addr; socklen_t len = sizeof(addr); int err; s = socket_loopback(family, sotype); if (s < 0) return s; err = xgetsockname(s, sockaddr(&addr), &len); if (err) return err; c = xsocket(family, sotype, 0); if (c < 0) return c; err = connect(c, sockaddr(&addr), len); if (err) { if (errno != EINPROGRESS) { FAIL_ERRNO("connect"); return err; } err = poll_connect(c, IO_TIMEOUT_SEC); if (err) { FAIL_ERRNO("poll_connect"); return err; } } switch (sotype & SOCK_TYPE_MASK) { case SOCK_DGRAM: err = xgetsockname(c, sockaddr(&addr), &len); if (err) return err; err = xconnect(s, sockaddr(&addr), len); if (err) return err; *p0 = take_fd(s); break; case SOCK_STREAM: case SOCK_SEQPACKET: p = xaccept_nonblock(s, NULL, NULL); if (p < 0) return p; *p0 = take_fd(p); break; default: FAIL("Unsupported socket type %#x", sotype); return -EOPNOTSUPP; } *p1 = take_fd(c); return 0; } static inline int create_socket_pairs(int family, int sotype, int *c0, int *c1, int *p0, int *p1) { int err; err = create_pair(family, sotype, c0, p0); if (err) return err; err = create_pair(family, sotype, c1, p1); if (err) { close(*c0); close(*p0); } return err; } #endif // __SOCKET_HELPERS__