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systemd/src/basic/socket-util.c
Daan De Meyer 0bac1ed242 tree-wide: Fix constness issues with newer glibc 
Latest glibc uses _Generic to have strstr() and other functions return
const char* or char* based on whether the input is a const char* or a
char*. This causes build failures as we previously always expected a char*.

Let's fix the compilation failures and add our own macros similar to glibc's
to have string functions that return a mutable or const pointer depending on
the input.
2025-11-25 20:49:39 +01:00

1992 lines
62 KiB
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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <fcntl.h>
#include <linux/if.h>
#include <linux/if_arp.h>
#include <mqueue.h>
#include <net/if.h>
#include <netdb.h>
#include <netinet/ip.h>
#include <poll.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include "alloc-util.h"
#include "errno-util.h"
#include "escape.h"
#include "fd-util.h"
#include "format-ifname.h"
#include "format-util.h"
#include "in-addr-util.h"
#include "io-util.h"
#include "log.h"
#include "memory-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "pidref.h"
#include "process-util.h"
#include "random-util.h"
#include "socket-util.h"
#include "sparse-endian.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "sysctl-util.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_inode_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_set_in_addr(
union sockaddr_union *u,
int family,
const union in_addr_union *a,
uint16_t port) {
assert(u);
assert(a);
switch (family) {
case AF_INET:
u->in = (struct sockaddr_in) {
.sin_family = AF_INET,
.sin_addr = a->in,
.sin_port = htobe16(port),
};
return 0;
case AF_INET6:
u->in6 = (struct sockaddr_in6) {
.sin6_family = AF_INET6,
.sin6_addr = a->in6,
.sin6_port = htobe16(port),
};
return 0;
default:
return -EAFNOSUPPORT;
}
}
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));
assert(ret);
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 {
const char *a = IN6_ADDR_TO_STRING(&sa->in6.sin6_addr);
if (include_port) {
if (asprintf(&p,
"[%s]:%u%s%s",
a,
be16toh(sa->in6.sin6_port),
sa->in6.sin6_scope_id != 0 ? "%" : "",
FORMAT_IFNAME_FULL(sa->in6.sin6_scope_id, FORMAT_IFNAME_IFINDEX)) < 0)
return -ENOMEM;
} else {
if (sa->in6.sin6_scope_id != 0)
p = strjoin(a, "%", FORMAT_IFNAME_FULL(sa->in6.sin6_scope_id, FORMAT_IFNAME_IFINDEX));
else
p = 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 = UCRED_INVALID;
/* 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(const struct sockaddr *sa, socklen_t salen, char **ret) {
char host[NI_MAXHOST];
int r;
assert(sa);
assert(salen >= sizeof(sa_family_t));
assert(ret);
r = getnameinfo(sa, salen, host, sizeof(host), /* service= */ NULL, /* service_len= */ 0, IDN_FLAGS);
if (r != 0) {
if (r == EAI_MEMORY)
return log_oom_debug();
if (r == EAI_SYSTEM)
log_debug_errno(errno, "getnameinfo() failed, ignoring: %m");
else
log_debug("getnameinfo() failed, ignoring: %s", gai_strerror(r));
return sockaddr_pretty(sa, salen, /* translate_ipv6= */ true, /* include_port= */ true, ret);
}
return strdup_to(ret, host);
}
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);
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 (!FLAGS_SET(flags, IFNAME_VALID_SPECIAL) && STR_IN_SET(p, "all", "default"))
return false;
for (const char *t = p; *t; t++) {
if (!ifname_valid_char(*t))
return false;
numeric = numeric && ascii_isdigit(*t);
}
/* 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;
assert(fd >= 0);
assert(ucred);
if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &u, &n) < 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) {
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) * 64U;
_cleanup_free_ gid_t *d = NULL;
assert(fd >= 0);
assert(ret);
long ngroups_max = sysconf(_SC_NGROUPS_MAX);
if (ngroups_max > 0)
n = MAX(n, sizeof(gid_t) * (socklen_t) ngroups_max);
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 (n > INT_MAX)
return -E2BIG;
*ret = TAKE_PTR(d);
return (int) n;
}
int getpeerpidfd(int fd) {
socklen_t n = sizeof(int);
int pidfd = -EBADF;
assert(fd >= 0);
if (getsockopt(fd, SOL_SOCKET, SO_PEERPIDFD, &pidfd, &n) < 0)
return -errno;
if (n != sizeof(int))
return -EIO;
return pidfd;
}
int getpeerpidref(int fd, PidRef *ret) {
int r;
assert(fd >= 0);
assert(ret);
int pidfd = getpeerpidfd(fd);
if (pidfd < 0) {
if (!ERRNO_IS_NEG_NOT_SUPPORTED(pidfd))
return pidfd;
struct ucred ucred;
r = getpeercred(fd, &ucred);
if (r < 0)
return r;
return pidref_set_pid(ret, ucred.pid);
}
return pidref_set_pidfd_consume(ret, pidfd);
}
ssize_t send_many_fds_iov_sa(
int transport_fd,
int *fds_array, size_t n_fds_array,
const struct iovec *iov, size_t iovlen,
const struct sockaddr *sa, socklen_t len,
int flags) {
_cleanup_free_ struct cmsghdr *cmsg = NULL;
struct msghdr mh = {
.msg_name = (struct sockaddr*) sa,
.msg_namelen = len,
.msg_iov = (struct iovec *)iov,
.msg_iovlen = iovlen,
};
ssize_t k;
assert(transport_fd >= 0);
assert(fds_array || n_fds_array == 0);
/* The kernel will reject sending more than SCM_MAX_FD FDs at once */
if (n_fds_array > SCM_MAX_FD)
return -E2BIG;
/* We need either an FD array or data to send. If there's nothing, return an error. */
if (n_fds_array == 0 && !iov)
return -EINVAL;
if (n_fds_array > 0) {
mh.msg_controllen = CMSG_SPACE(sizeof(int) * n_fds_array);
mh.msg_control = cmsg = malloc(mh.msg_controllen);
if (!cmsg)
return -ENOMEM;
*cmsg = (struct cmsghdr) {
.cmsg_len = CMSG_LEN(sizeof(int) * n_fds_array),
.cmsg_level = SOL_SOCKET,
.cmsg_type = SCM_RIGHTS,
};
memcpy(CMSG_DATA(cmsg), fds_array, sizeof(int) * n_fds_array);
}
k = sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags);
if (k < 0)
return (ssize_t) -errno;
return k;
}
ssize_t send_one_fd_iov_sa(
int transport_fd,
int fd,
const 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 = (struct iovec *)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_many_fds_iov(
int transport_fd,
struct iovec *iov, size_t iovlen,
int **ret_fds_array, size_t *ret_n_fds_array,
int flags) {
CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(int) * SCM_MAX_FD)) control;
struct msghdr mh = {
.msg_control = &control,
.msg_controllen = sizeof(control),
.msg_iov = iov,
.msg_iovlen = iovlen,
};
_cleanup_free_ int *fds_array = NULL;
size_t n_fds_array = 0;
struct cmsghdr *cmsg;
ssize_t k;
assert(transport_fd >= 0);
assert(ret_fds_array);
assert(ret_n_fds_array);
/*
* Receive many FDs via @transport_fd. We don't care for the transport-type. We retrieve all the FDs
* at once. This is best used in combination with send_many_fds().
*/
k = recvmsg_safe(transport_fd, &mh, MSG_CMSG_CLOEXEC | flags);
if (k < 0)
return k;
CMSG_FOREACH(cmsg, &mh)
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
size_t n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
if (!GREEDY_REALLOC_APPEND(fds_array, n_fds_array, CMSG_TYPED_DATA(cmsg, int), n)) {
cmsg_close_all(&mh);
return -ENOMEM;
}
}
if (n_fds_array == 0) {
cmsg_close_all(&mh);
/* If didn't receive an FD or any data, return an error. */
if (k == 0)
return -EIO;
}
*ret_fds_array = TAKE_PTR(fds_array);
*ret_n_fds_array = n_fds_array;
return k;
}
int receive_many_fds(int transport_fd, int **ret_fds_array, size_t *ret_n_fds_array, int flags) {
ssize_t k;
k = receive_many_fds_iov(transport_fd, NULL, 0, ret_fds_array, ret_n_fds_array, flags);
if (k == 0)
return 0;
/* k must be negative, since receive_many_fds_iov() only returns a positive value if data was received
* through the iov. */
assert(k < 0);
return (int) k;
}
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 = *CMSG_TYPED_DATA(found, int);
else
*ret_fd = -EBADF;
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);
}
}
ssize_t flush_mqueue(int fd) {
_cleanup_free_ char *buf = NULL;
struct mq_attr attr;
ssize_t count = 0;
int r;
assert(fd >= 0);
/* Similar to flush_fd() but flushes all messages from a POSIX message queue. */
for (;;) {
ssize_t l;
r = fd_wait_for_event(fd, POLLIN, /* timeout= */ 0);
if (r < 0) {
if (r == -EINTR)
continue;
return r;
}
if (r == 0)
return count;
if (!buf) {
/* Buffer must be at least as large as mq_msgsize. */
if (mq_getattr(fd, &attr) < 0)
return -errno;
buf = malloc(attr.mq_msgsize);
if (!buf)
return -ENOMEM;
}
l = mq_receive(fd, buf, attr.mq_msgsize, /* msg_prio = */ NULL);
if (l < 0) {
if (errno == EINTR)
continue;
if (errno == EAGAIN)
return count;
return -errno;
}
count += l;
}
}
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;
}
void* cmsg_find_and_copy_data(struct msghdr *mh, int level, int type, void *buf, size_t buf_len) {
struct cmsghdr *cmsg;
assert(mh);
assert(buf);
assert(buf_len > 0);
/* This is similar to cmsg_find_data(), but copy the found data to buf. This should be typically used
* when reading possibly unaligned data such as timestamp, as time_t is 64-bit and size_t is 32-bit on
* RISCV32. See issue #27241. */
cmsg = cmsg_find(mh, level, type, CMSG_LEN(buf_len));
if (!cmsg)
return NULL;
return memcpy_safe(buf, CMSG_DATA(cmsg), buf_len);
}
size_t sockaddr_ll_len(const struct sockaddr_ll *sa) {
/* Certain hardware address types (e.g Infiniband) do not fit into sll_addr
* (8 bytes) and run over the structure. This function returns the correct size that
* must be passed to kernel. */
assert(sa->sll_family == AF_PACKET);
size_t mac_len = sizeof(sa->sll_addr);
if (be16toh(sa->sll_hatype) == ARPHRD_ETHER)
mac_len = MAX(mac_len, (size_t) ETH_ALEN);
if (be16toh(sa->sll_hatype) == ARPHRD_INFINIBAND)
mac_len = MAX(mac_len, (size_t) INFINIBAND_ALEN);
return offsetof(struct sockaddr_ll, sll_addr) + mac_len;
}
size_t sockaddr_un_len(const struct sockaddr_un *sa) {
/* Covers only file system and abstract AF_UNIX socket addresses, but not unnamed socket addresses. */
assert(sa->sun_family == AF_UNIX);
return offsetof(struct sockaddr_un, sun_path) +
(sa->sun_path[0] == 0 ?
1 + strnlen(sa->sun_path+1, sizeof(sa->sun_path)-1) :
strnlen(sa->sun_path, sizeof(sa->sun_path))+1);
}
size_t sockaddr_len(const union sockaddr_union *sa) {
switch (sa->sa.sa_family) {
case AF_INET:
return sizeof(struct sockaddr_in);
case AF_INET6:
return sizeof(struct sockaddr_in6);
case AF_UNIX:
return sockaddr_un_len(&sa->un);
case AF_PACKET:
return sockaddr_ll_len(&sa->ll);
case AF_NETLINK:
return sizeof(struct sockaddr_nl);
case AF_VSOCK:
return sizeof(struct sockaddr_vm);
default:
assert_not_reached();
}
}
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 path[0] == '@' ? -EINVAL : -ENAMETOOLONG; /* return a recognizable error if this is
* too long to fit into a sockaddr_un, but
* is a file system path, and thus might be
* connectible via O_PATH indirection. */
*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 getsockopt_int(int fd, int level, int optname, int *ret) {
int v;
socklen_t sl = sizeof(v);
assert(fd >= 0);
assert(ret);
if (getsockopt(fd, level, optname, &v, &sl) < 0)
return negative_errno();
if (sl != sizeof(v))
return -EIO;
*ret = v;
return 0;
}
int socket_bind_to_ifname(int fd, const char *ifname) {
assert(fd >= 0);
/* Call with NULL to drop binding */
return RET_NERRNO(setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen_ptr(ifname)));
}
int socket_bind_to_ifindex(int fd, int ifindex) {
assert(fd >= 0);
if (ifindex <= 0)
/* Drop binding */
return RET_NERRNO(setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, NULL, 0));
return setsockopt_int(fd, SOL_SOCKET, SO_BINDTOIFINDEX, ifindex);
}
int socket_autobind(int fd, char **ret_name) {
_cleanup_free_ char *name = NULL;
uint64_t random;
int r;
/* Generate a random abstract socket name and bind fd to it. This is modeled after the kernel
* "autobind" feature, but uses 64-bit random number internally. */
assert(fd >= 0);
random = random_u64();
if (asprintf(&name, "@%" PRIu64, random) < 0)
return -ENOMEM;
union sockaddr_union sa;
assert_cc(DECIMAL_STR_MAX(uint64_t) < sizeof(sa.un.sun_path));
r = sockaddr_un_set_path(&sa.un, name);
if (r < 0)
return r;
if (bind(fd, &sa.sa, r) < 0)
return -errno;
if (ret_name)
*ret_name = TAKE_PTR(name);
return 0;
}
ssize_t recvmsg_safe(int sockfd, struct msghdr *msg, int flags) {
ssize_t n;
/* A wrapper around recvmsg() that checks for MSG_CTRUNC and MSG_TRUNC, and turns them into an error,
* in a reasonably safe way, closing any received fds in the error path.
*
* Note that unlike our usual coding style this might modify *msg on failure. */
assert(sockfd >= 0);
assert(msg);
n = recvmsg(sockfd, msg, flags);
if (n < 0)
return -errno;
if (FLAGS_SET(msg->msg_flags, MSG_CTRUNC) ||
(!FLAGS_SET(flags, MSG_PEEK) && FLAGS_SET(msg->msg_flags, MSG_TRUNC))) {
cmsg_close_all(msg);
return FLAGS_SET(msg->msg_flags, MSG_CTRUNC) ? -ECHRNG : -EXFULL;
}
return n;
}
int socket_get_family(int fd) {
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) {
if (af == AF_UNSPEC) {
af = socket_get_family(fd);
if (af < 0)
return af;
}
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);
if (af == AF_UNSPEC) {
af = socket_get_family(fd);
if (af < 0)
return af;
}
switch (af) {
case AF_INET:
return RET_NERRNO(setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)));
case AF_INET6:
return RET_NERRNO(setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)));
default:
return -EAFNOSUPPORT;
}
}
int socket_set_option(int fd, int af, int opt_ipv4, int opt_ipv6, int val) {
if (af == AF_UNSPEC) {
af = socket_get_family(fd);
if (af < 0)
return af;
}
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) {
af = socket_get_family(fd);
if (af < 0)
return af;
}
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;
}
static int connect_unix_path_simple(int fd, const char *path) {
union sockaddr_union sa = {
.un.sun_family = AF_UNIX,
};
size_t l;
assert(fd >= 0);
assert(path);
l = strlen(path);
assert(l > 0);
assert(l < sizeof(sa.un.sun_path));
memcpy(sa.un.sun_path, path, l + 1);
return RET_NERRNO(connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + l + 1));
}
static int connect_unix_inode(int fd, int inode_fd) {
assert(fd >= 0);
assert(inode_fd >= 0);
return connect_unix_path_simple(fd, FORMAT_PROC_FD_PATH(inode_fd));
}
int connect_unix_path(int fd, int dir_fd, const char *path) {
_cleanup_close_ int inode_fd = -EBADF;
assert(fd >= 0);
assert(dir_fd == AT_FDCWD || dir_fd >= 0);
/* Connects to the specified AF_UNIX socket in the file system. Works around the 108 byte size limit
* in sockaddr_un, by going via O_PATH if needed. This hence works for any kind of path. */
if (!path)
return connect_unix_inode(fd, dir_fd); /* If no path is specified, then dir_fd refers to the socket inode to connect to. */
/* Refuse zero length path early, to make sure AF_UNIX stack won't mistake this for an abstract
* namespace path, since first char is NUL */
if (isempty(path))
return -EINVAL;
/* Shortcut for the simple case */
if (dir_fd == AT_FDCWD && strlen(path) < sizeof_field(struct sockaddr_un, sun_path))
return connect_unix_path_simple(fd, path);
/* If dir_fd is specified, then we need to go the indirect O_PATH route, because connectat() does not
* exist. If the path is too long, we also need to take the indirect route, since we can't fit this
* into a sockaddr_un directly. */
inode_fd = openat(dir_fd, path, O_PATH|O_CLOEXEC);
if (inode_fd < 0)
return -errno;
return connect_unix_inode(fd, inode_fd);
}
int socket_address_parse_unix(SocketAddress *ret_address, const char *s) {
struct sockaddr_un un;
int r;
assert(ret_address);
assert(s);
if (!IN_SET(*s, '/', '@'))
return -EPROTO;
r = sockaddr_un_set_path(&un, s);
if (r < 0)
return r;
*ret_address = (SocketAddress) {
.sockaddr.un = un,
.size = r,
};
return 0;
}
int socket_address_equal_unix(const char *a, const char *b) {
SocketAddress socket_a, socket_b;
int r;
assert(a);
assert(b);
r = socket_address_parse_unix(&socket_a, a);
if (r < 0)
return r;
r = socket_address_parse_unix(&socket_b, b);
if (r < 0)
return r;
return sockaddr_equal(&socket_a.sockaddr, &socket_b.sockaddr);
}
int vsock_parse_port(const char *s, unsigned *ret) {
int r;
assert(ret);
if (!s)
return -EINVAL;
unsigned u;
r = safe_atou(s, &u);
if (r < 0)
return r;
/* Port 0 is apparently valid and not special in AF_VSOCK (unlike on IP). But VMADDR_PORT_ANY
* (UINT32_MAX) is. Hence refuse that. */
if (u == VMADDR_PORT_ANY)
return -EINVAL;
*ret = u;
return 0;
}
int vsock_parse_cid(const char *s, unsigned *ret) {
assert(ret);
if (!s)
return -EINVAL;
/* Parsed an AF_VSOCK "CID". This is a 32bit entity, and the usual type is "unsigned". We recognize
* the three special CIDs as strings, and otherwise parse the numeric CIDs. */
if (streq(s, "hypervisor"))
*ret = VMADDR_CID_HYPERVISOR;
else if (streq(s, "local"))
*ret = VMADDR_CID_LOCAL;
else if (streq(s, "host"))
*ret = VMADDR_CID_HOST;
else
return safe_atou(s, ret);
return 0;
}
int socket_address_parse_vsock(SocketAddress *ret_address, const char *s) {
/* AF_VSOCK socket in vsock:cid:port notation */
_cleanup_free_ char *n = NULL;
const char *e, *cid_start;
unsigned port, cid;
int type, r;
assert(ret_address);
assert(s);
if ((cid_start = startswith(s, "vsock:")))
type = 0;
else if ((cid_start = startswith(s, "vsock-dgram:")))
type = SOCK_DGRAM;
else if ((cid_start = startswith(s, "vsock-seqpacket:")))
type = SOCK_SEQPACKET;
else if ((cid_start = startswith(s, "vsock-stream:")))
type = SOCK_STREAM;
else
return -EPROTO;
e = strchr(cid_start, ':');
if (!e)
return -EINVAL;
r = vsock_parse_port(e+1, &port);
if (r < 0)
return r;
n = strndup(cid_start, e - cid_start);
if (!n)
return -ENOMEM;
if (isempty(n))
cid = VMADDR_CID_ANY;
else {
r = vsock_parse_cid(n, &cid);
if (r < 0)
return r;
}
*ret_address = (SocketAddress) {
.sockaddr.vm = {
.svm_family = AF_VSOCK,
.svm_cid = cid,
.svm_port = port,
},
.type = type,
.size = sizeof(struct sockaddr_vm),
};
return 0;
}
int vsock_get_local_cid(unsigned *ret) {
_cleanup_close_ int vsock_fd = -EBADF;
vsock_fd = open("/dev/vsock", O_RDONLY|O_CLOEXEC);
if (vsock_fd < 0)
return log_debug_errno(errno, "Failed to open %s: %m", "/dev/vsock");
unsigned tmp;
if (ioctl(vsock_fd, IOCTL_VM_SOCKETS_GET_LOCAL_CID, &tmp) < 0)
return log_debug_errno(errno, "Failed to query local AF_VSOCK CID: %m");
log_debug("Local AF_VSOCK CID: %u", tmp);
/* If ret == NULL, we're just want to check if AF_VSOCK is available, so accept
* any address. Otherwise, filter out special addresses that are cannot be used
* to identify _this_ machine from the outside. */
if (ret && IN_SET(tmp, VMADDR_CID_LOCAL, VMADDR_CID_HOST))
return log_debug_errno(SYNTHETIC_ERRNO(EADDRNOTAVAIL),
"IOCTL_VM_SOCKETS_GET_LOCAL_CID returned special value (%u), ignoring.", tmp);
if (ret)
*ret = tmp;
return 0;
}
int netlink_socket_get_multicast_groups(int fd, size_t *ret_len, uint32_t **ret_groups) {
_cleanup_free_ uint32_t *groups = NULL;
socklen_t len = 0, old_len;
assert(fd >= 0);
if (getsockopt(fd, SOL_NETLINK, NETLINK_LIST_MEMBERSHIPS, NULL, &len) < 0)
return -errno;
if (len == 0)
goto finalize;
groups = new0(uint32_t, len);
if (!groups)
return -ENOMEM;
old_len = len;
if (getsockopt(fd, SOL_NETLINK, NETLINK_LIST_MEMBERSHIPS, groups, &len) < 0)
return -errno;
if (old_len != len)
return -EIO;
finalize:
if (ret_len)
*ret_len = len;
if (ret_groups)
*ret_groups = TAKE_PTR(groups);
return 0;
}
int socket_get_cookie(int fd, uint64_t *ret) {
assert(fd >= 0);
uint64_t cookie = 0;
socklen_t cookie_len = sizeof(cookie);
if (getsockopt(fd, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len) < 0)
return -errno;
assert(cookie_len == sizeof(cookie));
if (ret)
*ret = cookie;
return 0;
}
void cmsg_close_all(struct msghdr *mh) {
assert(mh);
struct cmsghdr *cmsg;
CMSG_FOREACH(cmsg, mh) {
if (cmsg->cmsg_level != SOL_SOCKET)
continue;
if (cmsg->cmsg_type == SCM_RIGHTS)
close_many(CMSG_TYPED_DATA(cmsg, int),
(cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int));
else if (cmsg->cmsg_type == SCM_PIDFD) {
assert(cmsg->cmsg_len == CMSG_LEN(sizeof(int)));
safe_close(*CMSG_TYPED_DATA(cmsg, int));
}
}
}
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