| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <arpa/inet.h> |
| #include <errno.h> |
| #include <limits.h> |
| #include <net/if.h> |
| #include <netdb.h> |
| #include <netinet/ip.h> |
| #include <poll.h> |
| #include <stddef.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/ioctl.h> |
| #include <unistd.h> |
| #include <linux/if.h> |
| |
| #include "alloc-util.h" |
| #include "errno-util.h" |
| #include "escape.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "format-util.h" |
| #include "io-util.h" |
| #include "log.h" |
| #include "memory-util.h" |
| #include "parse-util.h" |
| #include "path-util.h" |
| #include "process-util.h" |
| #include "socket-util.h" |
| #include "string-table.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "sysctl-util.h" |
| #include "user-util.h" |
| #include "utf8.h" |
| |
| #if ENABLE_IDN |
| # define IDN_FLAGS NI_IDN |
| #else |
| # define IDN_FLAGS 0 |
| #endif |
| |
| static const char* const socket_address_type_table[] = { |
| [SOCK_STREAM] = "Stream", |
| [SOCK_DGRAM] = "Datagram", |
| [SOCK_RAW] = "Raw", |
| [SOCK_RDM] = "ReliableDatagram", |
| [SOCK_SEQPACKET] = "SequentialPacket", |
| [SOCK_DCCP] = "DatagramCongestionControl", |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP(socket_address_type, int); |
| |
| int socket_address_verify(const SocketAddress *a, bool strict) { |
| assert(a); |
| |
| /* With 'strict' we enforce additional sanity constraints which are not set by the standard, |
| * but should only apply to sockets we create ourselves. */ |
| |
| switch (socket_address_family(a)) { |
| |
| case AF_INET: |
| if (a->size != sizeof(struct sockaddr_in)) |
| return -EINVAL; |
| |
| if (a->sockaddr.in.sin_port == 0) |
| return -EINVAL; |
| |
| if (!IN_SET(a->type, 0, SOCK_STREAM, SOCK_DGRAM)) |
| return -EINVAL; |
| |
| return 0; |
| |
| case AF_INET6: |
| if (a->size != sizeof(struct sockaddr_in6)) |
| return -EINVAL; |
| |
| if (a->sockaddr.in6.sin6_port == 0) |
| return -EINVAL; |
| |
| if (!IN_SET(a->type, 0, SOCK_STREAM, SOCK_DGRAM)) |
| return -EINVAL; |
| |
| return 0; |
| |
| case AF_UNIX: |
| if (a->size < offsetof(struct sockaddr_un, sun_path)) |
| return -EINVAL; |
| if (a->size > sizeof(struct sockaddr_un) + !strict) |
| /* If !strict, allow one extra byte, since getsockname() on Linux will append |
| * a NUL byte if we have path sockets that are above sun_path's full size. */ |
| return -EINVAL; |
| |
| if (a->size > offsetof(struct sockaddr_un, sun_path) && |
| a->sockaddr.un.sun_path[0] != 0 && |
| strict) { |
| /* Only validate file system sockets here, and only in strict mode */ |
| const char *e; |
| |
| e = memchr(a->sockaddr.un.sun_path, 0, sizeof(a->sockaddr.un.sun_path)); |
| if (e) { |
| /* If there's an embedded NUL byte, make sure the size of the socket address matches it */ |
| if (a->size != offsetof(struct sockaddr_un, sun_path) + (e - a->sockaddr.un.sun_path) + 1) |
| return -EINVAL; |
| } else { |
| /* If there's no embedded NUL byte, then the size needs to match the whole |
| * structure or the structure with one extra NUL byte suffixed. (Yeah, Linux is awful, |
| * and considers both equivalent: getsockname() even extends sockaddr_un beyond its |
| * size if the path is non NUL terminated.) */ |
| if (!IN_SET(a->size, sizeof(a->sockaddr.un.sun_path), sizeof(a->sockaddr.un.sun_path)+1)) |
| return -EINVAL; |
| } |
| } |
| |
| if (!IN_SET(a->type, 0, SOCK_STREAM, SOCK_DGRAM, SOCK_SEQPACKET)) |
| return -EINVAL; |
| |
| return 0; |
| |
| case AF_NETLINK: |
| |
| if (a->size != sizeof(struct sockaddr_nl)) |
| return -EINVAL; |
| |
| if (!IN_SET(a->type, 0, SOCK_RAW, SOCK_DGRAM)) |
| return -EINVAL; |
| |
| return 0; |
| |
| case AF_VSOCK: |
| if (a->size != sizeof(struct sockaddr_vm)) |
| return -EINVAL; |
| |
| if (!IN_SET(a->type, 0, SOCK_STREAM, SOCK_DGRAM)) |
| return -EINVAL; |
| |
| return 0; |
| |
| default: |
| return -EAFNOSUPPORT; |
| } |
| } |
| |
| int socket_address_print(const SocketAddress *a, char **ret) { |
| int r; |
| |
| assert(a); |
| assert(ret); |
| |
| r = socket_address_verify(a, false); /* We do non-strict validation, because we want to be |
| * able to pretty-print any socket the kernel considers |
| * valid. We still need to do validation to know if we |
| * can meaningfully print the address. */ |
| if (r < 0) |
| return r; |
| |
| if (socket_address_family(a) == AF_NETLINK) { |
| _cleanup_free_ char *sfamily = NULL; |
| |
| r = netlink_family_to_string_alloc(a->protocol, &sfamily); |
| if (r < 0) |
| return r; |
| |
| r = asprintf(ret, "%s %u", sfamily, a->sockaddr.nl.nl_groups); |
| if (r < 0) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| return sockaddr_pretty(&a->sockaddr.sa, a->size, false, true, ret); |
| } |
| |
| bool socket_address_can_accept(const SocketAddress *a) { |
| assert(a); |
| |
| return |
| IN_SET(a->type, SOCK_STREAM, SOCK_SEQPACKET); |
| } |
| |
| bool socket_address_equal(const SocketAddress *a, const SocketAddress *b) { |
| assert(a); |
| assert(b); |
| |
| /* Invalid addresses are unequal to all */ |
| if (socket_address_verify(a, false) < 0 || |
| socket_address_verify(b, false) < 0) |
| return false; |
| |
| if (a->type != b->type) |
| return false; |
| |
| if (socket_address_family(a) != socket_address_family(b)) |
| return false; |
| |
| switch (socket_address_family(a)) { |
| |
| case AF_INET: |
| if (a->sockaddr.in.sin_addr.s_addr != b->sockaddr.in.sin_addr.s_addr) |
| return false; |
| |
| if (a->sockaddr.in.sin_port != b->sockaddr.in.sin_port) |
| return false; |
| |
| break; |
| |
| case AF_INET6: |
| if (memcmp(&a->sockaddr.in6.sin6_addr, &b->sockaddr.in6.sin6_addr, sizeof(a->sockaddr.in6.sin6_addr)) != 0) |
| return false; |
| |
| if (a->sockaddr.in6.sin6_port != b->sockaddr.in6.sin6_port) |
| return false; |
| |
| break; |
| |
| case AF_UNIX: |
| if (a->size <= offsetof(struct sockaddr_un, sun_path) || |
| b->size <= offsetof(struct sockaddr_un, sun_path)) |
| return false; |
| |
| if ((a->sockaddr.un.sun_path[0] == 0) != (b->sockaddr.un.sun_path[0] == 0)) |
| return false; |
| |
| if (a->sockaddr.un.sun_path[0]) { |
| if (!path_equal_or_files_same(a->sockaddr.un.sun_path, b->sockaddr.un.sun_path, 0)) |
| return false; |
| } else { |
| if (a->size != b->size) |
| return false; |
| |
| if (memcmp(a->sockaddr.un.sun_path, b->sockaddr.un.sun_path, a->size) != 0) |
| return false; |
| } |
| |
| break; |
| |
| case AF_NETLINK: |
| if (a->protocol != b->protocol) |
| return false; |
| |
| if (a->sockaddr.nl.nl_groups != b->sockaddr.nl.nl_groups) |
| return false; |
| |
| break; |
| |
| case AF_VSOCK: |
| if (a->sockaddr.vm.svm_cid != b->sockaddr.vm.svm_cid) |
| return false; |
| |
| if (a->sockaddr.vm.svm_port != b->sockaddr.vm.svm_port) |
| return false; |
| |
| break; |
| |
| default: |
| /* Cannot compare, so we assume the addresses are different */ |
| return false; |
| } |
| |
| return true; |
| } |
| |
| const char* socket_address_get_path(const SocketAddress *a) { |
| assert(a); |
| |
| if (socket_address_family(a) != AF_UNIX) |
| return NULL; |
| |
| if (a->sockaddr.un.sun_path[0] == 0) |
| return NULL; |
| |
| /* Note that this is only safe because we know that there's an extra NUL byte after the sockaddr_un |
| * structure. On Linux AF_UNIX file system socket addresses don't have to be NUL terminated if they take up the |
| * full sun_path space. */ |
| assert_cc(sizeof(union sockaddr_union) >= sizeof(struct sockaddr_un)+1); |
| return a->sockaddr.un.sun_path; |
| } |
| |
| bool socket_ipv6_is_supported(void) { |
| static int cached = -1; |
| |
| if (cached < 0) { |
| |
| if (access("/proc/net/if_inet6", F_OK) < 0) { |
| |
| if (errno != ENOENT) { |
| log_debug_errno(errno, "Unexpected error when checking whether /proc/net/if_inet6 exists: %m"); |
| return false; |
| } |
| |
| cached = false; |
| } else |
| cached = true; |
| } |
| |
| return cached; |
| } |
| |
| bool socket_ipv6_is_enabled(void) { |
| _cleanup_free_ char *v = NULL; |
| int r; |
| |
| /* Much like socket_ipv6_is_supported(), but also checks that the sysctl that disables IPv6 on all |
| * interfaces isn't turned on */ |
| |
| if (!socket_ipv6_is_supported()) |
| return false; |
| |
| r = sysctl_read_ip_property(AF_INET6, "all", "disable_ipv6", &v); |
| if (r < 0) { |
| log_debug_errno(r, "Unexpected error reading 'net.ipv6.conf.all.disable_ipv6' sysctl: %m"); |
| return true; |
| } |
| |
| r = parse_boolean(v); |
| if (r < 0) { |
| log_debug_errno(r, "Failed to pare 'net.ipv6.conf.all.disable_ipv6' sysctl: %m"); |
| return true; |
| } |
| |
| return !r; |
| } |
| |
| bool socket_address_matches_fd(const SocketAddress *a, int fd) { |
| SocketAddress b; |
| socklen_t solen; |
| |
| assert(a); |
| assert(fd >= 0); |
| |
| b.size = sizeof(b.sockaddr); |
| if (getsockname(fd, &b.sockaddr.sa, &b.size) < 0) |
| return false; |
| |
| if (b.sockaddr.sa.sa_family != a->sockaddr.sa.sa_family) |
| return false; |
| |
| solen = sizeof(b.type); |
| if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &b.type, &solen) < 0) |
| return false; |
| |
| if (b.type != a->type) |
| return false; |
| |
| if (a->protocol != 0) { |
| solen = sizeof(b.protocol); |
| if (getsockopt(fd, SOL_SOCKET, SO_PROTOCOL, &b.protocol, &solen) < 0) |
| return false; |
| |
| if (b.protocol != a->protocol) |
| return false; |
| } |
| |
| return socket_address_equal(a, &b); |
| } |
| |
| int sockaddr_port(const struct sockaddr *_sa, unsigned *ret_port) { |
| const union sockaddr_union *sa = (const union sockaddr_union*) _sa; |
| |
| /* Note, this returns the port as 'unsigned' rather than 'uint16_t', as AF_VSOCK knows larger ports */ |
| |
| assert(sa); |
| |
| switch (sa->sa.sa_family) { |
| |
| case AF_INET: |
| *ret_port = be16toh(sa->in.sin_port); |
| return 0; |
| |
| case AF_INET6: |
| *ret_port = be16toh(sa->in6.sin6_port); |
| return 0; |
| |
| case AF_VSOCK: |
| *ret_port = sa->vm.svm_port; |
| return 0; |
| |
| default: |
| return -EAFNOSUPPORT; |
| } |
| } |
| |
| const union in_addr_union *sockaddr_in_addr(const struct sockaddr *_sa) { |
| const union sockaddr_union *sa = (const union sockaddr_union*) _sa; |
| |
| if (!sa) |
| return NULL; |
| |
| switch (sa->sa.sa_family) { |
| |
| case AF_INET: |
| return (const union in_addr_union*) &sa->in.sin_addr; |
| |
| case AF_INET6: |
| return (const union in_addr_union*) &sa->in6.sin6_addr; |
| |
| default: |
| return NULL; |
| } |
| } |
| |
| int sockaddr_pretty( |
| const struct sockaddr *_sa, |
| socklen_t salen, |
| bool translate_ipv6, |
| bool include_port, |
| char **ret) { |
| |
| union sockaddr_union *sa = (union sockaddr_union*) _sa; |
| char *p; |
| int r; |
| |
| assert(sa); |
| assert(salen >= sizeof(sa->sa.sa_family)); |
| |
| switch (sa->sa.sa_family) { |
| |
| case AF_INET: { |
| uint32_t a; |
| |
| a = be32toh(sa->in.sin_addr.s_addr); |
| |
| if (include_port) |
| r = asprintf(&p, |
| "%u.%u.%u.%u:%u", |
| a >> 24, (a >> 16) & 0xFF, (a >> 8) & 0xFF, a & 0xFF, |
| be16toh(sa->in.sin_port)); |
| else |
| r = asprintf(&p, |
| "%u.%u.%u.%u", |
| a >> 24, (a >> 16) & 0xFF, (a >> 8) & 0xFF, a & 0xFF); |
| if (r < 0) |
| return -ENOMEM; |
| break; |
| } |
| |
| case AF_INET6: { |
| static const unsigned char ipv4_prefix[] = { |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF |
| }; |
| |
| if (translate_ipv6 && |
| memcmp(&sa->in6.sin6_addr, ipv4_prefix, sizeof(ipv4_prefix)) == 0) { |
| const uint8_t *a = sa->in6.sin6_addr.s6_addr+12; |
| if (include_port) |
| r = asprintf(&p, |
| "%u.%u.%u.%u:%u", |
| a[0], a[1], a[2], a[3], |
| be16toh(sa->in6.sin6_port)); |
| else |
| r = asprintf(&p, |
| "%u.%u.%u.%u", |
| a[0], a[1], a[2], a[3]); |
| if (r < 0) |
| return -ENOMEM; |
| } else { |
| char a[INET6_ADDRSTRLEN], ifname[IF_NAMESIZE + 1]; |
| |
| inet_ntop(AF_INET6, &sa->in6.sin6_addr, a, sizeof(a)); |
| if (sa->in6.sin6_scope_id != 0) |
| format_ifname_full(sa->in6.sin6_scope_id, ifname, FORMAT_IFNAME_IFINDEX); |
| |
| if (include_port) { |
| r = asprintf(&p, |
| "[%s]:%u%s%s", |
| a, |
| be16toh(sa->in6.sin6_port), |
| sa->in6.sin6_scope_id != 0 ? "%" : "", |
| sa->in6.sin6_scope_id != 0 ? ifname : ""); |
| if (r < 0) |
| return -ENOMEM; |
| } else { |
| p = sa->in6.sin6_scope_id != 0 ? strjoin(a, "%", ifname) : strdup(a); |
| if (!p) |
| return -ENOMEM; |
| } |
| } |
| |
| break; |
| } |
| |
| case AF_UNIX: |
| if (salen <= offsetof(struct sockaddr_un, sun_path) || |
| (sa->un.sun_path[0] == 0 && salen == offsetof(struct sockaddr_un, sun_path) + 1)) |
| /* The name must have at least one character (and the leading NUL does not count) */ |
| p = strdup("<unnamed>"); |
| else { |
| /* Note that we calculate the path pointer here through the .un_buffer[] field, in order to |
| * outtrick bounds checking tools such as ubsan, which are too smart for their own good: on |
| * Linux the kernel may return sun_path[] data one byte longer than the declared size of the |
| * field. */ |
| char *path = (char*) sa->un_buffer + offsetof(struct sockaddr_un, sun_path); |
| size_t path_len = salen - offsetof(struct sockaddr_un, sun_path); |
| |
| if (path[0] == 0) { |
| /* Abstract socket. When parsing address information from, we |
| * explicitly reject overly long paths and paths with embedded NULs. |
| * But we might get such a socket from the outside. Let's return |
| * something meaningful and printable in this case. */ |
| |
| _cleanup_free_ char *e = NULL; |
| |
| e = cescape_length(path + 1, path_len - 1); |
| if (!e) |
| return -ENOMEM; |
| |
| p = strjoin("@", e); |
| } else { |
| if (path[path_len - 1] == '\0') |
| /* We expect a terminating NUL and don't print it */ |
| path_len --; |
| |
| p = cescape_length(path, path_len); |
| } |
| } |
| if (!p) |
| return -ENOMEM; |
| |
| break; |
| |
| case AF_VSOCK: |
| if (include_port) { |
| if (sa->vm.svm_cid == VMADDR_CID_ANY) |
| r = asprintf(&p, "vsock::%u", sa->vm.svm_port); |
| else |
| r = asprintf(&p, "vsock:%u:%u", sa->vm.svm_cid, sa->vm.svm_port); |
| } else |
| r = asprintf(&p, "vsock:%u", sa->vm.svm_cid); |
| if (r < 0) |
| return -ENOMEM; |
| break; |
| |
| default: |
| return -EOPNOTSUPP; |
| } |
| |
| *ret = p; |
| return 0; |
| } |
| |
| int getpeername_pretty(int fd, bool include_port, char **ret) { |
| union sockaddr_union sa; |
| socklen_t salen = sizeof(sa); |
| int r; |
| |
| assert(fd >= 0); |
| assert(ret); |
| |
| if (getpeername(fd, &sa.sa, &salen) < 0) |
| return -errno; |
| |
| if (sa.sa.sa_family == AF_UNIX) { |
| struct ucred ucred = {}; |
| |
| /* UNIX connection sockets are anonymous, so let's use |
| * PID/UID as pretty credentials instead */ |
| |
| r = getpeercred(fd, &ucred); |
| if (r < 0) |
| return r; |
| |
| if (asprintf(ret, "PID "PID_FMT"/UID "UID_FMT, ucred.pid, ucred.uid) < 0) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| /* For remote sockets we translate IPv6 addresses back to IPv4 |
| * if applicable, since that's nicer. */ |
| |
| return sockaddr_pretty(&sa.sa, salen, true, include_port, ret); |
| } |
| |
| int getsockname_pretty(int fd, char **ret) { |
| union sockaddr_union sa; |
| socklen_t salen = sizeof(sa); |
| |
| assert(fd >= 0); |
| assert(ret); |
| |
| if (getsockname(fd, &sa.sa, &salen) < 0) |
| return -errno; |
| |
| /* For local sockets we do not translate IPv6 addresses back |
| * to IPv6 if applicable, since this is usually used for |
| * listening sockets where the difference between IPv4 and |
| * IPv6 matters. */ |
| |
| return sockaddr_pretty(&sa.sa, salen, false, true, ret); |
| } |
| |
| int socknameinfo_pretty(union sockaddr_union *sa, socklen_t salen, char **_ret) { |
| int r; |
| char host[NI_MAXHOST], *ret; |
| |
| assert(_ret); |
| |
| r = getnameinfo(&sa->sa, salen, host, sizeof(host), NULL, 0, IDN_FLAGS); |
| if (r != 0) { |
| int saved_errno = errno; |
| |
| r = sockaddr_pretty(&sa->sa, salen, true, true, &ret); |
| if (r < 0) |
| return r; |
| |
| log_debug_errno(saved_errno, "getnameinfo(%s) failed: %m", ret); |
| } else { |
| ret = strdup(host); |
| if (!ret) |
| return -ENOMEM; |
| } |
| |
| *_ret = ret; |
| return 0; |
| } |
| |
| static const char* const netlink_family_table[] = { |
| [NETLINK_ROUTE] = "route", |
| [NETLINK_FIREWALL] = "firewall", |
| [NETLINK_INET_DIAG] = "inet-diag", |
| [NETLINK_NFLOG] = "nflog", |
| [NETLINK_XFRM] = "xfrm", |
| [NETLINK_SELINUX] = "selinux", |
| [NETLINK_ISCSI] = "iscsi", |
| [NETLINK_AUDIT] = "audit", |
| [NETLINK_FIB_LOOKUP] = "fib-lookup", |
| [NETLINK_CONNECTOR] = "connector", |
| [NETLINK_NETFILTER] = "netfilter", |
| [NETLINK_IP6_FW] = "ip6-fw", |
| [NETLINK_DNRTMSG] = "dnrtmsg", |
| [NETLINK_KOBJECT_UEVENT] = "kobject-uevent", |
| [NETLINK_GENERIC] = "generic", |
| [NETLINK_SCSITRANSPORT] = "scsitransport", |
| [NETLINK_ECRYPTFS] = "ecryptfs", |
| [NETLINK_RDMA] = "rdma", |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(netlink_family, int, INT_MAX); |
| |
| static const char* const socket_address_bind_ipv6_only_table[_SOCKET_ADDRESS_BIND_IPV6_ONLY_MAX] = { |
| [SOCKET_ADDRESS_DEFAULT] = "default", |
| [SOCKET_ADDRESS_BOTH] = "both", |
| [SOCKET_ADDRESS_IPV6_ONLY] = "ipv6-only" |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP(socket_address_bind_ipv6_only, SocketAddressBindIPv6Only); |
| |
| SocketAddressBindIPv6Only socket_address_bind_ipv6_only_or_bool_from_string(const char *n) { |
| int r; |
| |
| r = parse_boolean(n); |
| if (r > 0) |
| return SOCKET_ADDRESS_IPV6_ONLY; |
| if (r == 0) |
| return SOCKET_ADDRESS_BOTH; |
| |
| return socket_address_bind_ipv6_only_from_string(n); |
| } |
| |
| bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b) { |
| assert(a); |
| assert(b); |
| |
| if (a->sa.sa_family != b->sa.sa_family) |
| return false; |
| |
| if (a->sa.sa_family == AF_INET) |
| return a->in.sin_addr.s_addr == b->in.sin_addr.s_addr; |
| |
| if (a->sa.sa_family == AF_INET6) |
| return memcmp(&a->in6.sin6_addr, &b->in6.sin6_addr, sizeof(a->in6.sin6_addr)) == 0; |
| |
| if (a->sa.sa_family == AF_VSOCK) |
| return a->vm.svm_cid == b->vm.svm_cid; |
| |
| return false; |
| } |
| |
| int fd_set_sndbuf(int fd, size_t n, bool increase) { |
| int r, value; |
| socklen_t l = sizeof(value); |
| |
| if (n > INT_MAX) |
| return -ERANGE; |
| |
| r = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, &l); |
| if (r >= 0 && l == sizeof(value) && increase ? (size_t) value >= n*2 : (size_t) value == n*2) |
| return 0; |
| |
| /* First, try to set the buffer size with SO_SNDBUF. */ |
| r = setsockopt_int(fd, SOL_SOCKET, SO_SNDBUF, n); |
| if (r < 0) |
| return r; |
| |
| /* SO_SNDBUF above may set to the kernel limit, instead of the requested size. |
| * So, we need to check the actual buffer size here. */ |
| l = sizeof(value); |
| r = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, &l); |
| if (r >= 0 && l == sizeof(value) && increase ? (size_t) value >= n*2 : (size_t) value == n*2) |
| return 1; |
| |
| /* If we have the privileges we will ignore the kernel limit. */ |
| r = setsockopt_int(fd, SOL_SOCKET, SO_SNDBUFFORCE, n); |
| if (r < 0) |
| return r; |
| |
| return 1; |
| } |
| |
| int fd_set_rcvbuf(int fd, size_t n, bool increase) { |
| int r, value; |
| socklen_t l = sizeof(value); |
| |
| if (n > INT_MAX) |
| return -ERANGE; |
| |
| r = getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, &l); |
| if (r >= 0 && l == sizeof(value) && increase ? (size_t) value >= n*2 : (size_t) value == n*2) |
| return 0; |
| |
| /* First, try to set the buffer size with SO_RCVBUF. */ |
| r = setsockopt_int(fd, SOL_SOCKET, SO_RCVBUF, n); |
| if (r < 0) |
| return r; |
| |
| /* SO_RCVBUF above may set to the kernel limit, instead of the requested size. |
| * So, we need to check the actual buffer size here. */ |
| l = sizeof(value); |
| r = getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, &l); |
| if (r >= 0 && l == sizeof(value) && increase ? (size_t) value >= n*2 : (size_t) value == n*2) |
| return 1; |
| |
| /* If we have the privileges we will ignore the kernel limit. */ |
| r = setsockopt_int(fd, SOL_SOCKET, SO_RCVBUFFORCE, n); |
| if (r < 0) |
| return r; |
| |
| return 1; |
| } |
| |
| static const char* const ip_tos_table[] = { |
| [IPTOS_LOWDELAY] = "low-delay", |
| [IPTOS_THROUGHPUT] = "throughput", |
| [IPTOS_RELIABILITY] = "reliability", |
| [IPTOS_LOWCOST] = "low-cost", |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos, int, 0xff); |
| |
| bool ifname_valid_char(char a) { |
| if ((unsigned char) a >= 127U) |
| return false; |
| |
| if ((unsigned char) a <= 32U) |
| return false; |
| |
| if (IN_SET(a, |
| ':', /* colons are used by the legacy "alias" interface logic */ |
| '/', /* slashes cannot work, since we need to use network interfaces in sysfs paths, and in paths slashes are separators */ |
| '%')) /* %d is used in the kernel's weird foo%d format string naming feature which we really really don't want to ever run into by accident */ |
| return false; |
| |
| return true; |
| } |
| |
| bool ifname_valid_full(const char *p, IfnameValidFlags flags) { |
| bool numeric = true; |
| |
| /* Checks whether a network interface name is valid. This is inspired by dev_valid_name() in the kernel sources |
| * but slightly stricter, as we only allow non-control, non-space ASCII characters in the interface name. We |
| * also don't permit names that only container numbers, to avoid confusion with numeric interface indexes. */ |
| |
| assert(!(flags & ~_IFNAME_VALID_ALL)); |
| |
| if (isempty(p)) |
| return false; |
| |
| /* A valid ifindex? If so, it's valid iff IFNAME_VALID_NUMERIC is set */ |
| if (parse_ifindex(p) >= 0) |
| return flags & IFNAME_VALID_NUMERIC; |
| |
| if (flags & IFNAME_VALID_ALTERNATIVE) { |
| if (strlen(p) >= ALTIFNAMSIZ) |
| return false; |
| } else { |
| if (strlen(p) >= IFNAMSIZ) |
| return false; |
| } |
| |
| if (dot_or_dot_dot(p)) |
| return false; |
| |
| /* Let's refuse "all" and "default" as interface name, to avoid collisions with the special sysctl |
| * directories /proc/sys/net/{ipv4,ipv6}/conf/{all,default} */ |
| if (STR_IN_SET(p, "all", "default")) |
| return false; |
| |
| for (const char *t = p; *t; t++) { |
| if (!ifname_valid_char(*t)) |
| return false; |
| |
| numeric = numeric && (*t >= '0' && *t <= '9'); |
| } |
| |
| /* It's fully numeric but didn't parse as valid ifindex above? if so, it must be too large or zero or |
| * so, let's refuse that. */ |
| if (numeric) |
| return false; |
| |
| return true; |
| } |
| |
| bool address_label_valid(const char *p) { |
| |
| if (isempty(p)) |
| return false; |
| |
| if (strlen(p) >= IFNAMSIZ) |
| return false; |
| |
| while (*p) { |
| if ((uint8_t) *p >= 127U) |
| return false; |
| |
| if ((uint8_t) *p <= 31U) |
| return false; |
| p++; |
| } |
| |
| return true; |
| } |
| |
| int getpeercred(int fd, struct ucred *ucred) { |
| socklen_t n = sizeof(struct ucred); |
| struct ucred u; |
| int r; |
| |
| assert(fd >= 0); |
| assert(ucred); |
| |
| r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &u, &n); |
| if (r < 0) |
| return -errno; |
| |
| if (n != sizeof(struct ucred)) |
| return -EIO; |
| |
| /* Check if the data is actually useful and not suppressed due to namespacing issues */ |
| if (!pid_is_valid(u.pid)) |
| return -ENODATA; |
| |
| /* Note that we don't check UID/GID here, as namespace translation works differently there: instead of |
| * receiving in "invalid" user/group we get the overflow UID/GID. */ |
| |
| *ucred = u; |
| return 0; |
| } |
| |
| int getpeersec(int fd, char **ret) { |
| _cleanup_free_ char *s = NULL; |
| socklen_t n = 64; |
| |
| assert(fd >= 0); |
| assert(ret); |
| |
| for (;;) { |
| s = new0(char, n+1); |
| if (!s) |
| return -ENOMEM; |
| |
| if (getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n) >= 0) |
| break; |
| |
| if (errno != ERANGE) |
| return -errno; |
| |
| s = mfree(s); |
| } |
| |
| if (isempty(s)) |
| return -EOPNOTSUPP; |
| |
| *ret = TAKE_PTR(s); |
| |
| return 0; |
| } |
| |
| int getpeergroups(int fd, gid_t **ret) { |
| socklen_t n = sizeof(gid_t) * 64; |
| _cleanup_free_ gid_t *d = NULL; |
| |
| assert(fd >= 0); |
| assert(ret); |
| |
| for (;;) { |
| d = malloc(n); |
| if (!d) |
| return -ENOMEM; |
| |
| if (getsockopt(fd, SOL_SOCKET, SO_PEERGROUPS, d, &n) >= 0) |
| break; |
| |
| if (errno != ERANGE) |
| return -errno; |
| |
| d = mfree(d); |
| } |
| |
| assert_se(n % sizeof(gid_t) == 0); |
| n /= sizeof(gid_t); |
| |
| if ((socklen_t) (int) n != n) |
| return -E2BIG; |
| |
| *ret = TAKE_PTR(d); |
| |
| return (int) n; |
| } |
| |
| ssize_t send_one_fd_iov_sa( |
| int transport_fd, |
| int fd, |
| struct iovec *iov, size_t iovlen, |
| const struct sockaddr *sa, socklen_t len, |
| int flags) { |
| |
| CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int))) control = {}; |
| struct msghdr mh = { |
| .msg_name = (struct sockaddr*) sa, |
| .msg_namelen = len, |
| .msg_iov = iov, |
| .msg_iovlen = iovlen, |
| }; |
| ssize_t k; |
| |
| assert(transport_fd >= 0); |
| |
| /* |
| * We need either an FD or data to send. |
| * If there's nothing, return an error. |
| */ |
| if (fd < 0 && !iov) |
| return -EINVAL; |
| |
| if (fd >= 0) { |
| struct cmsghdr *cmsg; |
| |
| mh.msg_control = &control; |
| mh.msg_controllen = sizeof(control); |
| |
| cmsg = CMSG_FIRSTHDR(&mh); |
| cmsg->cmsg_level = SOL_SOCKET; |
| cmsg->cmsg_type = SCM_RIGHTS; |
| cmsg->cmsg_len = CMSG_LEN(sizeof(int)); |
| memcpy(CMSG_DATA(cmsg), &fd, sizeof(int)); |
| } |
| k = sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags); |
| if (k < 0) |
| return (ssize_t) -errno; |
| |
| return k; |
| } |
| |
| int send_one_fd_sa( |
| int transport_fd, |
| int fd, |
| const struct sockaddr *sa, socklen_t len, |
| int flags) { |
| |
| assert(fd >= 0); |
| |
| return (int) send_one_fd_iov_sa(transport_fd, fd, NULL, 0, sa, len, flags); |
| } |
| |
| ssize_t receive_one_fd_iov( |
| int transport_fd, |
| struct iovec *iov, size_t iovlen, |
| int flags, |
| int *ret_fd) { |
| |
| CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int))) control; |
| struct msghdr mh = { |
| .msg_control = &control, |
| .msg_controllen = sizeof(control), |
| .msg_iov = iov, |
| .msg_iovlen = iovlen, |
| }; |
| struct cmsghdr *found; |
| ssize_t k; |
| |
| assert(transport_fd >= 0); |
| assert(ret_fd); |
| |
| /* |
| * Receive a single FD via @transport_fd. We don't care for |
| * the transport-type. We retrieve a single FD at most, so for |
| * packet-based transports, the caller must ensure to send |
| * only a single FD per packet. This is best used in |
| * combination with send_one_fd(). |
| */ |
| |
| k = recvmsg_safe(transport_fd, &mh, MSG_CMSG_CLOEXEC | flags); |
| if (k < 0) |
| return k; |
| |
| found = cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, CMSG_LEN(sizeof(int))); |
| if (!found) { |
| cmsg_close_all(&mh); |
| |
| /* If didn't receive an FD or any data, return an error. */ |
| if (k == 0) |
| return -EIO; |
| } |
| |
| if (found) |
| *ret_fd = *(int*) CMSG_DATA(found); |
| else |
| *ret_fd = -1; |
| |
| return k; |
| } |
| |
| int receive_one_fd(int transport_fd, int flags) { |
| int fd; |
| ssize_t k; |
| |
| k = receive_one_fd_iov(transport_fd, NULL, 0, flags, &fd); |
| if (k == 0) |
| return fd; |
| |
| /* k must be negative, since receive_one_fd_iov() only returns |
| * a positive value if data was received through the iov. */ |
| assert(k < 0); |
| return (int) k; |
| } |
| |
| ssize_t next_datagram_size_fd(int fd) { |
| ssize_t l; |
| int k; |
| |
| /* This is a bit like FIONREAD/SIOCINQ, however a bit more powerful. The difference being: recv(MSG_PEEK) will |
| * actually cause the next datagram in the queue to be validated regarding checksums, which FIONREAD doesn't |
| * do. This difference is actually of major importance as we need to be sure that the size returned here |
| * actually matches what we will read with recvmsg() next, as otherwise we might end up allocating a buffer of |
| * the wrong size. */ |
| |
| l = recv(fd, NULL, 0, MSG_PEEK|MSG_TRUNC); |
| if (l < 0) { |
| if (IN_SET(errno, EOPNOTSUPP, EFAULT)) |
| goto fallback; |
| |
| return -errno; |
| } |
| if (l == 0) |
| goto fallback; |
| |
| return l; |
| |
| fallback: |
| k = 0; |
| |
| /* Some sockets (AF_PACKET) do not support null-sized recv() with MSG_TRUNC set, let's fall back to FIONREAD |
| * for them. Checksums don't matter for raw sockets anyway, hence this should be fine. */ |
| |
| if (ioctl(fd, FIONREAD, &k) < 0) |
| return -errno; |
| |
| return (ssize_t) k; |
| } |
| |
| /* Put a limit on how many times will attempt to call accept4(). We loop |
| * only on "transient" errors, but let's make sure we don't loop forever. */ |
| #define MAX_FLUSH_ITERATIONS 1024 |
| |
| int flush_accept(int fd) { |
| |
| int r, b; |
| socklen_t l = sizeof(b); |
| |
| /* Similar to flush_fd() but flushes all incoming connections by accepting and immediately closing |
| * them. */ |
| |
| if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &b, &l) < 0) |
| return -errno; |
| |
| assert(l == sizeof(b)); |
| if (!b) /* Let's check if this socket accepts connections before calling accept(). accept4() can |
| * return EOPNOTSUPP if the fd is not a listening socket, which we should treat as a fatal |
| * error, or in case the incoming TCP connection triggered a network issue, which we want to |
| * treat as a transient error. Thus, let's rule out the first reason for EOPNOTSUPP early, so |
| * we can loop safely on transient errors below. */ |
| return -ENOTTY; |
| |
| for (unsigned iteration = 0;; iteration++) { |
| int cfd; |
| |
| r = fd_wait_for_event(fd, POLLIN, 0); |
| if (r < 0) { |
| if (r == -EINTR) |
| continue; |
| |
| return r; |
| } |
| if (r == 0) |
| return 0; |
| |
| if (iteration >= MAX_FLUSH_ITERATIONS) |
| return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), |
| "Failed to flush connections within " STRINGIFY(MAX_FLUSH_ITERATIONS) " iterations."); |
| |
| cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); |
| if (cfd < 0) { |
| if (errno == EAGAIN) |
| return 0; |
| |
| if (ERRNO_IS_ACCEPT_AGAIN(errno)) |
| continue; |
| |
| return -errno; |
| } |
| |
| safe_close(cfd); |
| } |
| } |
| |
| struct cmsghdr* cmsg_find(struct msghdr *mh, int level, int type, socklen_t length) { |
| struct cmsghdr *cmsg; |
| |
| assert(mh); |
| |
| CMSG_FOREACH(cmsg, mh) |
| if (cmsg->cmsg_level == level && |
| cmsg->cmsg_type == type && |
| (length == (socklen_t) -1 || length == cmsg->cmsg_len)) |
| return cmsg; |
| |
| return NULL; |
| } |
| |
| int socket_ioctl_fd(void) { |
| int fd; |
| |
| /* Create a socket to invoke the various network interface ioctl()s on. Traditionally only AF_INET was good for |
| * that. Since kernel 4.6 AF_NETLINK works for this too. We first try to use AF_INET hence, but if that's not |
| * available (for example, because it is made unavailable via SECCOMP or such), we'll fall back to the more |
| * generic AF_NETLINK. */ |
| |
| fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC, 0); |
| if (fd < 0) |
| fd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, NETLINK_GENERIC); |
| if (fd < 0) |
| return -errno; |
| |
| return fd; |
| } |
| |
| int sockaddr_un_unlink(const struct sockaddr_un *sa) { |
| const char *p, * nul; |
| |
| assert(sa); |
| |
| if (sa->sun_family != AF_UNIX) |
| return -EPROTOTYPE; |
| |
| if (sa->sun_path[0] == 0) /* Nothing to do for abstract sockets */ |
| return 0; |
| |
| /* The path in .sun_path is not necessarily NUL terminated. Let's fix that. */ |
| nul = memchr(sa->sun_path, 0, sizeof(sa->sun_path)); |
| if (nul) |
| p = sa->sun_path; |
| else |
| p = memdupa_suffix0(sa->sun_path, sizeof(sa->sun_path)); |
| |
| if (unlink(p) < 0) |
| return -errno; |
| |
| return 1; |
| } |
| |
| int sockaddr_un_set_path(struct sockaddr_un *ret, const char *path) { |
| size_t l; |
| |
| assert(ret); |
| assert(path); |
| |
| /* Initialize ret->sun_path from the specified argument. This will interpret paths starting with '@' as |
| * abstract namespace sockets, and those starting with '/' as regular filesystem sockets. It won't accept |
| * anything else (i.e. no relative paths), to avoid ambiguities. Note that this function cannot be used to |
| * reference paths in the abstract namespace that include NUL bytes in the name. */ |
| |
| l = strlen(path); |
| if (l < 2) |
| return -EINVAL; |
| if (!IN_SET(path[0], '/', '@')) |
| return -EINVAL; |
| |
| /* Don't allow paths larger than the space in sockaddr_un. Note that we are a tiny bit more restrictive than |
| * the kernel is: we insist on NUL termination (both for abstract namespace and regular file system socket |
| * addresses!), which the kernel doesn't. We do this to reduce chance of incompatibility with other apps that |
| * do not expect non-NUL terminated file system path. */ |
| if (l+1 > sizeof(ret->sun_path)) |
| return -EINVAL; |
| |
| *ret = (struct sockaddr_un) { |
| .sun_family = AF_UNIX, |
| }; |
| |
| if (path[0] == '@') { |
| /* Abstract namespace socket */ |
| memcpy(ret->sun_path + 1, path + 1, l); /* copy *with* trailing NUL byte */ |
| return (int) (offsetof(struct sockaddr_un, sun_path) + l); /* 🔥 *don't* 🔥 include trailing NUL in size */ |
| |
| } else { |
| assert(path[0] == '/'); |
| |
| /* File system socket */ |
| memcpy(ret->sun_path, path, l + 1); /* copy *with* trailing NUL byte */ |
| return (int) (offsetof(struct sockaddr_un, sun_path) + l + 1); /* include trailing NUL in size */ |
| } |
| } |
| |
| int socket_bind_to_ifname(int fd, const char *ifname) { |
| assert(fd >= 0); |
| |
| /* Call with NULL to drop binding */ |
| |
| if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen_ptr(ifname)) < 0) |
| return -errno; |
| |
| return 0; |
| } |
| |
| int socket_bind_to_ifindex(int fd, int ifindex) { |
| char ifname[IF_NAMESIZE + 1]; |
| int r; |
| |
| assert(fd >= 0); |
| |
| if (ifindex <= 0) { |
| /* Drop binding */ |
| if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, NULL, 0) < 0) |
| return -errno; |
| |
| return 0; |
| } |
| |
| r = setsockopt_int(fd, SOL_SOCKET, SO_BINDTOIFINDEX, ifindex); |
| if (r != -ENOPROTOOPT) |
| return r; |
| |
| /* Fall back to SO_BINDTODEVICE on kernels < 5.0 which didn't have SO_BINDTOIFINDEX */ |
| if (!format_ifname(ifindex, ifname)) |
| return -errno; |
| |
| return socket_bind_to_ifname(fd, ifname); |
| } |
| |
| ssize_t recvmsg_safe(int sockfd, struct msghdr *msg, int flags) { |
| ssize_t n; |
| |
| /* A wrapper around recvmsg() that checks for MSG_CTRUNC, and turns it into an error, in a reasonably |
| * safe way, closing any SCM_RIGHTS fds in the error path. |
| * |
| * Note that unlike our usual coding style this might modify *msg on failure. */ |
| |
| n = recvmsg(sockfd, msg, flags); |
| if (n < 0) |
| return -errno; |
| |
| if (FLAGS_SET(msg->msg_flags, MSG_CTRUNC)) { |
| cmsg_close_all(msg); |
| return -EXFULL; /* a recognizable error code */ |
| } |
| |
| return n; |
| } |
| |
| int socket_get_family(int fd, int *ret) { |
| int af; |
| socklen_t sl = sizeof(af); |
| |
| if (getsockopt(fd, SOL_SOCKET, SO_DOMAIN, &af, &sl) < 0) |
| return -errno; |
| |
| if (sl != sizeof(af)) |
| return -EINVAL; |
| |
| return af; |
| } |
| |
| int socket_set_recvpktinfo(int fd, int af, bool b) { |
| int r; |
| |
| if (af == AF_UNSPEC) { |
| r = socket_get_family(fd, &af); |
| if (r < 0) |
| return r; |
| } |
| |
| switch (af) { |
| |
| case AF_INET: |
| return setsockopt_int(fd, IPPROTO_IP, IP_PKTINFO, b); |
| |
| case AF_INET6: |
| return setsockopt_int(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, b); |
| |
| case AF_NETLINK: |
| return setsockopt_int(fd, SOL_NETLINK, NETLINK_PKTINFO, b); |
| |
| case AF_PACKET: |
| return setsockopt_int(fd, SOL_PACKET, PACKET_AUXDATA, b); |
| |
| default: |
| return -EAFNOSUPPORT; |
| } |
| } |
| |
| int socket_set_unicast_if(int fd, int af, int ifi) { |
| be32_t ifindex_be = htobe32(ifi); |
| int r; |
| |
| if (af == AF_UNSPEC) { |
| r = socket_get_family(fd, &af); |
| if (r < 0) |
| return r; |
| } |
| |
| switch (af) { |
| |
| case AF_INET: |
| if (setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)) < 0) |
| return -errno; |
| |
| return 0; |
| |
| case AF_INET6: |
| if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)) < 0) |
| return -errno; |
| |
| return 0; |
| |
| default: |
| return -EAFNOSUPPORT; |
| } |
| } |
| |
| int systemd_socket_set_option(int fd, int af, int opt_ipv4, int opt_ipv6, int val) { |
| int r; |
| |
| if (af == AF_UNSPEC) { |
| r = socket_get_family(fd, &af); |
| if (r < 0) |
| return r; |
| } |
| |
| switch (af) { |
| |
| case AF_INET: |
| return setsockopt_int(fd, IPPROTO_IP, opt_ipv4, val); |
| |
| case AF_INET6: |
| return setsockopt_int(fd, IPPROTO_IPV6, opt_ipv6, val); |
| |
| default: |
| return -EAFNOSUPPORT; |
| } |
| } |
| |
| int socket_get_mtu(int fd, int af, size_t *ret) { |
| int mtu, r; |
| |
| if (af == AF_UNSPEC) { |
| r = socket_get_family(fd, &af); |
| if (r < 0) |
| return r; |
| } |
| |
| switch (af) { |
| |
| case AF_INET: |
| r = getsockopt_int(fd, IPPROTO_IP, IP_MTU, &mtu); |
| break; |
| |
| case AF_INET6: |
| r = getsockopt_int(fd, IPPROTO_IPV6, IPV6_MTU, &mtu); |
| break; |
| |
| default: |
| return -EAFNOSUPPORT; |
| } |
| |
| if (r < 0) |
| return r; |
| if (mtu <= 0) |
| return -EINVAL; |
| |
| *ret = (size_t) mtu; |
| return 0; |
| } |
