socket-util.c revision 2ca0435be9359bde3020eeb528c2a6d72ac1e0b0
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
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 <assert.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <net/if.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stddef.h>
#include <sys/ioctl.h>
#include "macro.h"
#include "util.h"
#include "mkdir.h"
#include "path-util.h"
#include "socket-util.h"
#include "missing.h"
#include "fileio.h"
int socket_address_parse(SocketAddress *a, const char *s) {
int r;
char *e, *n;
unsigned u;
assert(a);
assert(s);
zero(*a);
a->type = SOCK_STREAM;
if (*s == '[') {
/* IPv6 in [x:.....:z]:p notation */
if (!socket_ipv6_is_supported()) {
log_warning("Binding to IPv6 address not available since kernel does not support IPv6.");
return -EAFNOSUPPORT;
}
if (!(e = strchr(s+1, ']')))
return -EINVAL;
if (!(n = strndup(s+1, e-s-1)))
return -ENOMEM;
errno = 0;
if (inet_pton(AF_INET6, n, &a->sockaddr.in6.sin6_addr) <= 0) {
free(n);
return errno != 0 ? -errno : -EINVAL;
}
free(n);
e++;
if (*e != ':')
return -EINVAL;
e++;
if ((r = safe_atou(e, &u)) < 0)
return r;
if (u <= 0 || u > 0xFFFF)
return -EINVAL;
a->sockaddr.in6.sin6_family = AF_INET6;
a->sockaddr.in6.sin6_port = htons((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 {
if ((e = strchr(s, ':'))) {
if ((r = safe_atou(e+1, &u)) < 0)
return r;
if (u <= 0 || u > 0xFFFF)
return -EINVAL;
if (!(n = strndup(s, e-s)))
return -ENOMEM;
/* IPv4 in w.x.y.z:p notation? */
if ((r = inet_pton(AF_INET, n, &a->sockaddr.in4.sin_addr)) < 0) {
free(n);
return -errno;
}
if (r > 0) {
/* Gotcha, it's a traditional IPv4 address */
free(n);
a->sockaddr.in4.sin_family = AF_INET;
a->sockaddr.in4.sin_port = htons((uint16_t) u);
a->size = sizeof(struct sockaddr_in);
} else {
unsigned idx;
if (strlen(n) > IF_NAMESIZE-1) {
free(n);
return -EINVAL;
}
/* Uh, our last resort, an interface name */
idx = if_nametoindex(n);
free(n);
if (idx == 0)
return -EINVAL;
if (!socket_ipv6_is_supported()) {
log_warning("Binding to interface is not available since kernel does not support IPv6.");
return -EAFNOSUPPORT;
}
a->sockaddr.in6.sin6_family = AF_INET6;
a->sockaddr.in6.sin6_port = htons((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 = htons((uint16_t) u);
a->sockaddr.in6.sin6_addr = in6addr_any;
a->size = sizeof(struct sockaddr_in6);
} else {
a->sockaddr.in4.sin_family = AF_INET;
a->sockaddr.in4.sin_port = htons((uint16_t) u);
a->sockaddr.in4.sin_addr.s_addr = INADDR_ANY;
a->size = sizeof(struct sockaddr_in);
}
}
}
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 ? -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.in4.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 */
if (!(e = memchr(a->sockaddr.un.sun_path, 0, sizeof(a->sockaddr.un.sun_path))))
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 **p) {
int r;
assert(a);
assert(p);
if ((r = socket_address_verify(a)) < 0)
return r;
switch (socket_address_family(a)) {
case AF_INET: {
char *ret;
if (!(ret = new(char, INET_ADDRSTRLEN+1+5+1)))
return -ENOMEM;
if (!inet_ntop(AF_INET, &a->sockaddr.in4.sin_addr, ret, INET_ADDRSTRLEN)) {
free(ret);
return -errno;
}
sprintf(strchr(ret, 0), ":%u", ntohs(a->sockaddr.in4.sin_port));
*p = ret;
return 0;
}
case AF_INET6: {
char *ret;
if (!(ret = new(char, 1+INET6_ADDRSTRLEN+2+5+1)))
return -ENOMEM;
ret[0] = '[';
if (!inet_ntop(AF_INET6, &a->sockaddr.in6.sin6_addr, ret+1, INET6_ADDRSTRLEN)) {
free(ret);
return -errno;
}
sprintf(strchr(ret, 0), "]:%u", ntohs(a->sockaddr.in6.sin6_port));
*p = ret;
return 0;
}
case AF_UNIX: {
char *ret;
if (a->size <= offsetof(struct sockaddr_un, sun_path)) {
if (!(ret = strdup("<unnamed>")))
return -ENOMEM;
} else if (a->sockaddr.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 */
if (!(ret = new(char, sizeof(a->sockaddr.un.sun_path)+1)))
return -ENOMEM;
ret[0] = '@';
memcpy(ret+1, a->sockaddr.un.sun_path+1, sizeof(a->sockaddr.un.sun_path)-1);
ret[sizeof(a->sockaddr.un.sun_path)] = 0;
} else {
if (!(ret = strdup(a->sockaddr.un.sun_path)))
return -ENOMEM;
}
*p = ret;
return 0;
}
case AF_NETLINK: {
char _cleanup_free_ *sfamily = NULL;
r = netlink_family_to_string_alloc(a->protocol, &sfamily);
if (r < 0)
return r;
r = asprintf(p, "%s %u", sfamily, a->sockaddr.nl.nl_groups);
if (r < 0)
return -ENOMEM;
return 0;
}
default:
return -EINVAL;
}
}
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 (a->size != b->size)
return false;
if (socket_address_family(a) != socket_address_family(b))
return false;
switch (socket_address_family(a)) {
case AF_INET:
if (a->sockaddr.in4.sin_addr.s_addr != b->sockaddr.in4.sin_addr.s_addr)
return false;
if (a->sockaddr.in4.sin_port != b->sockaddr.in4.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->sockaddr.un.sun_path[0] == 0) != (b->sockaddr.un.sun_path[0] == 0))
return false;
if (a->sockaddr.un.sun_path[0]) {
if (!strneq(a->sockaddr.un.sun_path, b->sockaddr.un.sun_path, sizeof(a->sockaddr.un.sun_path)))
return false;
} else {
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);
}
bool socket_address_needs_mount(const SocketAddress *a, const char *prefix) {
assert(a);
if (socket_address_family(a) != AF_UNIX)
return false;
if (a->sockaddr.un.sun_path[0] == 0)
return false;
return path_startswith(a->sockaddr.un.sun_path, prefix);
}
bool socket_ipv6_is_supported(void) {
char *l = 0;
bool enabled;
if (access("/sys/module/ipv6", F_OK) != 0)
return 0;
/* If we can't check "disable" parameter, assume enabled */
if (read_one_line_file("/sys/module/ipv6/parameters/disable", &l) < 0)
return 1;
/* If module was loaded with disable=1 no IPv6 available */
enabled = l[0] == '0';
free(l);
return enabled;
}
bool socket_address_matches_fd(const SocketAddress *a, int fd) {
union sockaddr_union sa;
socklen_t salen = sizeof(sa), solen;
int protocol, type;
assert(a);
assert(fd >= 0);
if (getsockname(fd, &sa.sa, &salen) < 0)
return false;
if (sa.sa.sa_family != a->sockaddr.sa.sa_family)
return false;
solen = sizeof(type);
if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &type, &solen) < 0)
return false;
if (type != a->type)
return false;
if (a->protocol != 0) {
solen = sizeof(protocol);
if (getsockopt(fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &solen) < 0)
return false;
if (protocol != a->protocol)
return false;
}
switch (sa.sa.sa_family) {
case AF_INET:
return sa.in4.sin_port == a->sockaddr.in4.sin_port &&
sa.in4.sin_addr.s_addr == a->sockaddr.in4.sin_addr.s_addr;
case AF_INET6:
return sa.in6.sin6_port == a->sockaddr.in6.sin6_port &&
memcmp(&sa.in6.sin6_addr, &a->sockaddr.in6.sin6_addr, sizeof(struct in6_addr)) == 0;
case AF_UNIX:
return salen == a->size &&
memcmp(sa.un.sun_path, a->sockaddr.un.sun_path, salen - offsetof(struct sockaddr_un, sun_path)) == 0;
}
return false;
}
int make_socket_fd(const char* address, int flags) {
SocketAddress a;
int fd, r;
char _cleanup_free_ *p = NULL;
r = socket_address_parse(&a, address);
if (r < 0) {
log_error("failed to parse socket: %s", strerror(-r));
return r;
}
fd = socket(socket_address_family(&a), flags, 0);
if (fd < 0) {
log_error("socket(): %m");
return -errno;
}
r = socket_address_print(&a, &p);
if (r < 0) {
log_error("socket_address_print(): %s", strerror(-r));
return r;
}
log_info("Listening on %s", p);
r = bind(fd, &a.sockaddr.sa, a.size);
if (r < 0) {
log_error("bind to %s: %m", address);
return -errno;
}
r = listen(fd, SOMAXCONN);
if (r < 0) {
log_error("listen on %s: %m", address);
return -errno;
}
return fd;
}
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);