diff options
Diffstat (limited to 'src/basic/socket-util.c')
| -rw-r--r-- | src/basic/socket-util.c | 1079 |
1 files changed, 0 insertions, 1079 deletions
diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c deleted file mode 100644 index 1662c04705..0000000000 --- a/src/basic/socket-util.c +++ /dev/null @@ -1,1079 +0,0 @@ -/*** - This file is part of systemd. - - Copyright 2010 Lennart Poettering - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#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 <string.h> -#include <unistd.h> - -#include "alloc-util.h" -#include "fd-util.h" -#include "fileio.h" -#include "formats-util.h" -#include "log.h" -#include "macro.h" -#include "missing.h" -#include "parse-util.h" -#include "path-util.h" -#include "socket-util.h" -#include "string-table.h" -#include "string-util.h" -#include "strv.h" -#include "user-util.h" -#include "utf8.h" -#include "util.h" - -int socket_address_parse(SocketAddress *a, const char *s) { - char *e, *n; - unsigned u; - int r; - - assert(a); - assert(s); - - zero(*a); - a->type = SOCK_STREAM; - - if (*s == '[') { - /* IPv6 in [x:.....:z]:p notation */ - - e = strchr(s+1, ']'); - if (!e) - return -EINVAL; - - n = strndupa(s+1, e-s-1); - - errno = 0; - if (inet_pton(AF_INET6, n, &a->sockaddr.in6.sin6_addr) <= 0) - return errno > 0 ? -errno : -EINVAL; - - e++; - if (*e != ':') - return -EINVAL; - - e++; - r = safe_atou(e, &u); - if (r < 0) - return r; - - if (u <= 0 || u > 0xFFFF) - return -EINVAL; - - a->sockaddr.in6.sin6_family = AF_INET6; - a->sockaddr.in6.sin6_port = htobe16((uint16_t)u); - a->size = sizeof(struct sockaddr_in6); - - } else if (*s == '/') { - /* AF_UNIX socket */ - - size_t l; - - l = strlen(s); - if (l >= sizeof(a->sockaddr.un.sun_path)) - return -EINVAL; - - a->sockaddr.un.sun_family = AF_UNIX; - memcpy(a->sockaddr.un.sun_path, s, l); - a->size = offsetof(struct sockaddr_un, sun_path) + l + 1; - - } else if (*s == '@') { - /* Abstract AF_UNIX socket */ - size_t l; - - l = strlen(s+1); - if (l >= sizeof(a->sockaddr.un.sun_path) - 1) - return -EINVAL; - - a->sockaddr.un.sun_family = AF_UNIX; - memcpy(a->sockaddr.un.sun_path+1, s+1, l); - a->size = offsetof(struct sockaddr_un, sun_path) + 1 + l; - - } else { - e = strchr(s, ':'); - if (e) { - r = safe_atou(e+1, &u); - if (r < 0) - return r; - - if (u <= 0 || u > 0xFFFF) - return -EINVAL; - - n = strndupa(s, e-s); - - /* IPv4 in w.x.y.z:p notation? */ - r = inet_pton(AF_INET, n, &a->sockaddr.in.sin_addr); - if (r < 0) - return -errno; - - if (r > 0) { - /* Gotcha, it's a traditional IPv4 address */ - a->sockaddr.in.sin_family = AF_INET; - a->sockaddr.in.sin_port = htobe16((uint16_t)u); - a->size = sizeof(struct sockaddr_in); - } else { - unsigned idx; - - if (strlen(n) > IF_NAMESIZE-1) - return -EINVAL; - - /* Uh, our last resort, an interface name */ - idx = if_nametoindex(n); - if (idx == 0) - return -EINVAL; - - a->sockaddr.in6.sin6_family = AF_INET6; - a->sockaddr.in6.sin6_port = htobe16((uint16_t)u); - a->sockaddr.in6.sin6_scope_id = idx; - a->sockaddr.in6.sin6_addr = in6addr_any; - a->size = sizeof(struct sockaddr_in6); - } - } else { - - /* Just a port */ - r = safe_atou(s, &u); - if (r < 0) - return r; - - if (u <= 0 || u > 0xFFFF) - return -EINVAL; - - if (socket_ipv6_is_supported()) { - a->sockaddr.in6.sin6_family = AF_INET6; - a->sockaddr.in6.sin6_port = htobe16((uint16_t)u); - a->sockaddr.in6.sin6_addr = in6addr_any; - a->size = sizeof(struct sockaddr_in6); - } else { - a->sockaddr.in.sin_family = AF_INET; - a->sockaddr.in.sin_port = htobe16((uint16_t)u); - a->sockaddr.in.sin_addr.s_addr = INADDR_ANY; - a->size = sizeof(struct sockaddr_in); - } - } - } - - return 0; -} - -int socket_address_parse_and_warn(SocketAddress *a, const char *s) { - SocketAddress b; - int r; - - /* Similar to socket_address_parse() but warns for IPv6 sockets when we don't support them. */ - - r = socket_address_parse(&b, s); - if (r < 0) - return r; - - if (!socket_ipv6_is_supported() && b.sockaddr.sa.sa_family == AF_INET6) { - log_warning("Binding to IPv6 address not available since kernel does not support IPv6."); - return -EAFNOSUPPORT; - } - - *a = b; - return 0; -} - -int socket_address_parse_netlink(SocketAddress *a, const char *s) { - int family; - unsigned group = 0; - _cleanup_free_ char *sfamily = NULL; - assert(a); - assert(s); - - zero(*a); - a->type = SOCK_RAW; - - errno = 0; - if (sscanf(s, "%ms %u", &sfamily, &group) < 1) - return errno > 0 ? -errno : -EINVAL; - - family = netlink_family_from_string(sfamily); - if (family < 0) - return -EINVAL; - - a->sockaddr.nl.nl_family = AF_NETLINK; - a->sockaddr.nl.nl_groups = group; - - a->type = SOCK_RAW; - a->size = sizeof(struct sockaddr_nl); - a->protocol = family; - - return 0; -} - -int socket_address_verify(const SocketAddress *a) { - assert(a); - - 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 (a->type != SOCK_STREAM && a->type != 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 (a->type != SOCK_STREAM && a->type != SOCK_DGRAM) - return -EINVAL; - - return 0; - - case AF_UNIX: - if (a->size < offsetof(struct sockaddr_un, sun_path)) - return -EINVAL; - - if (a->size > offsetof(struct sockaddr_un, sun_path)) { - - if (a->sockaddr.un.sun_path[0] != 0) { - char *e; - - /* path */ - e = memchr(a->sockaddr.un.sun_path, 0, sizeof(a->sockaddr.un.sun_path)); - if (!e) - return -EINVAL; - - if (a->size != offsetof(struct sockaddr_un, sun_path) + (e - a->sockaddr.un.sun_path) + 1) - return -EINVAL; - } - } - - if (a->type != SOCK_STREAM && a->type != SOCK_DGRAM && a->type != SOCK_SEQPACKET) - return -EINVAL; - - return 0; - - case AF_NETLINK: - - if (a->size != sizeof(struct sockaddr_nl)) - return -EINVAL; - - if (a->type != SOCK_RAW && a->type != 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); - 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 - a->type == SOCK_STREAM || - a->type == 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) < 0 || - socket_address_verify(b) < 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)) - 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; - - default: - /* Cannot compare, so we assume the addresses are different */ - return false; - } - - return true; -} - -bool socket_address_is(const SocketAddress *a, const char *s, int type) { - struct SocketAddress b; - - assert(a); - assert(s); - - if (socket_address_parse(&b, s) < 0) - return false; - - b.type = type; - - return socket_address_equal(a, &b); -} - -bool socket_address_is_netlink(const SocketAddress *a, const char *s) { - struct SocketAddress b; - - assert(a); - assert(s); - - if (socket_address_parse_netlink(&b, s) < 0) - return false; - - return socket_address_equal(a, &b); -} - -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; - - return a->sockaddr.un.sun_path; -} - -bool socket_ipv6_is_supported(void) { - if (access("/proc/net/if_inet6", F_OK) != 0) - return false; - - return true; -} - -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) { - union sockaddr_union *sa = (union sockaddr_union*) _sa; - - assert(sa); - - if (!IN_SET(sa->sa.sa_family, AF_INET, AF_INET6)) - return -EAFNOSUPPORT; - - return be16toh(sa->sa.sa_family == AF_INET6 ? sa->in6.sin6_port : sa->in.sin_port); -} - -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]; - - inet_ntop(AF_INET6, &sa->in6.sin6_addr, a, sizeof(a)); - - if (include_port) { - r = asprintf(&p, - "[%s]:%u", - a, - be16toh(sa->in6.sin6_port)); - if (r < 0) - return -ENOMEM; - } else { - p = strdup(a); - if (!p) - return -ENOMEM; - } - } - - break; - } - - case AF_UNIX: - if (salen <= offsetof(struct sockaddr_un, sun_path)) { - p = strdup("<unnamed>"); - if (!p) - return -ENOMEM; - - } else if (sa->un.sun_path[0] == 0) { - /* abstract */ - - /* FIXME: We assume we can print the - * socket path here and that it hasn't - * more than one NUL byte. That is - * actually an invalid assumption */ - - p = new(char, sizeof(sa->un.sun_path)+1); - if (!p) - return -ENOMEM; - - p[0] = '@'; - memcpy(p+1, sa->un.sun_path+1, sizeof(sa->un.sun_path)-1); - p[sizeof(sa->un.sun_path)] = 0; - - } else { - p = strndup(sa->un.sun_path, sizeof(sa->un.sun_path)); - if (!p) - 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, - NI_IDN|NI_IDN_USE_STD3_ASCII_RULES); - 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; -} - -int getnameinfo_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; - - return socknameinfo_pretty(&sa, salen, ret); -} - -int socket_address_unlink(SocketAddress *a) { - assert(a); - - if (socket_address_family(a) != AF_UNIX) - return 0; - - if (a->sockaddr.un.sun_path[0] == 0) - return 0; - - if (unlink(a->sockaddr.un.sun_path) < 0) - return -errno; - - return 1; -} - -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" -}; - -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); - -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; - - return false; -} - -int fd_inc_sndbuf(int fd, size_t n) { - int r, value; - socklen_t l = sizeof(value); - - r = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, &l); - if (r >= 0 && l == sizeof(value) && (size_t) value >= n*2) - return 0; - - /* If we have the privileges we will ignore the kernel limit. */ - - value = (int) n; - if (setsockopt(fd, SOL_SOCKET, SO_SNDBUFFORCE, &value, sizeof(value)) < 0) - if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, sizeof(value)) < 0) - return -errno; - - return 1; -} - -int fd_inc_rcvbuf(int fd, size_t n) { - int r, value; - socklen_t l = sizeof(value); - - r = getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, &l); - if (r >= 0 && l == sizeof(value) && (size_t) value >= n*2) - return 0; - - /* If we have the privileges we will ignore the kernel limit. */ - - value = (int) n; - if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &value, sizeof(value)) < 0) - if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, sizeof(value)) < 0) - return -errno; - 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(const char *p) { - 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. */ - - if (isempty(p)) - return false; - - if (strlen(p) >= IFNAMSIZ) - return false; - - if (STR_IN_SET(p, ".", "..")) - return false; - - while (*p) { - if ((unsigned char) *p >= 127U) - return false; - - if ((unsigned char) *p <= 32U) - return false; - - if (*p == ':' || *p == '/') - return false; - - numeric = numeric && (*p >= '0' && *p <= '9'); - p++; - } - - if (numeric) - return false; - - 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 (u.pid <= 0) - return -ENODATA; - if (u.uid == UID_INVALID) - return -ENODATA; - if (u.gid == GID_INVALID) - return -ENODATA; - - *ucred = u; - return 0; -} - -int getpeersec(int fd, char **ret) { - socklen_t n = 64; - char *s; - int r; - - assert(fd >= 0); - assert(ret); - - s = new0(char, n); - if (!s) - return -ENOMEM; - - r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n); - if (r < 0) { - free(s); - - if (errno != ERANGE) - return -errno; - - s = new0(char, n); - if (!s) - return -ENOMEM; - - r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n); - if (r < 0) { - free(s); - return -errno; - } - } - - if (isempty(s)) { - free(s); - return -EOPNOTSUPP; - } - - *ret = s; - return 0; -} - -int send_one_fd_sa( - int transport_fd, - int fd, - const struct sockaddr *sa, socklen_t len, - int flags) { - - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int))]; - } control = {}; - struct msghdr mh = { - .msg_name = (struct sockaddr*) sa, - .msg_namelen = len, - .msg_control = &control, - .msg_controllen = sizeof(control), - }; - struct cmsghdr *cmsg; - - assert(transport_fd >= 0); - assert(fd >= 0); - - 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)); - - mh.msg_controllen = CMSG_SPACE(sizeof(int)); - if (sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags) < 0) - return -errno; - - return 0; -} - -int receive_one_fd(int transport_fd, int flags) { - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int))]; - } control = {}; - struct msghdr mh = { - .msg_control = &control, - .msg_controllen = sizeof(control), - }; - struct cmsghdr *cmsg, *found = NULL; - - assert(transport_fd >= 0); - - /* - * 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(). - */ - - if (recvmsg(transport_fd, &mh, MSG_NOSIGNAL | MSG_CMSG_CLOEXEC | flags) < 0) - return -errno; - - CMSG_FOREACH(cmsg, &mh) { - if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_RIGHTS && - cmsg->cmsg_len == CMSG_LEN(sizeof(int))) { - assert(!found); - found = cmsg; - break; - } - } - - if (!found) { - cmsg_close_all(&mh); - return -EIO; - } - - return *(int*) CMSG_DATA(found); -} - -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 (errno == EOPNOTSUPP || errno == 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; -} - -int flush_accept(int fd) { - - struct pollfd pollfd = { - .fd = fd, - .events = POLLIN, - }; - int r; - - - /* Similar to flush_fd() but flushes all incoming connection by accepting them and immediately closing them. */ - - for (;;) { - int cfd; - - r = poll(&pollfd, 1, 0); - if (r < 0) { - if (errno == EINTR) - continue; - - return -errno; - - } else if (r == 0) - return 0; - - cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); - if (cfd < 0) { - if (errno == EINTR) - continue; - - if (errno == EAGAIN) - return 0; - - return -errno; - } - - 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; -} |