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Systemd/src/shared/socket-util.c
Zbigniew Jędrzejewski-Szmek bcb161b023 errno is positive 
Make sure we compare errno against positive error codes.
The ones in hwclock.c and install.c can have an impact, the
rest are unlikely to be hit or in code that isn't widely
used.

Also check that errno > 0, to help gcc know that we are
returning a negative error code.
2013-04-11 19:13:18 -04:00

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/*-*- 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 > 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.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);
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