summaryrefslogtreecommitdiff
path: root/src/basic/socket-util.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/basic/socket-util.c')
-rw-r--r--src/basic/socket-util.c350
1 files changed, 257 insertions, 93 deletions
diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index a913102e13..91bf801cdf 100644
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -15,6 +15,7 @@
#include <unistd.h>
#include "alloc-util.h"
+#include "escape.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-util.h"
@@ -50,14 +51,16 @@ static const char* const socket_address_type_table[] = {
DEFINE_STRING_TABLE_LOOKUP(socket_address_type, int);
int socket_address_parse(SocketAddress *a, const char *s) {
- char *e, *n;
+ _cleanup_free_ char *n = NULL;
+ char *e;
int r;
assert(a);
assert(s);
- zero(*a);
- a->type = SOCK_STREAM;
+ *a = (SocketAddress) {
+ .type = SOCK_STREAM,
+ };
if (*s == '[') {
uint16_t port;
@@ -68,7 +71,9 @@ int socket_address_parse(SocketAddress *a, const char *s) {
if (!e)
return -EINVAL;
- n = strndupa(s+1, e-s-1);
+ n = strndup(s+1, e-s-1);
+ if (!n)
+ return -ENOMEM;
errno = 0;
if (inet_pton(AF_INET6, n, &a->sockaddr.in6.sin6_addr) <= 0)
@@ -93,7 +98,9 @@ int socket_address_parse(SocketAddress *a, const char *s) {
size_t l;
l = strlen(s);
- if (l >= sizeof(a->sockaddr.un.sun_path))
+ if (l >= sizeof(a->sockaddr.un.sun_path)) /* Note that we refuse non-NUL-terminated sockets when
+ * parsing (the kernel itself is less strict here in what it
+ * accepts) */
return -EINVAL;
a->sockaddr.un.sun_family = AF_UNIX;
@@ -105,7 +112,11 @@ int socket_address_parse(SocketAddress *a, const char *s) {
size_t l;
l = strlen(s+1);
- if (l >= sizeof(a->sockaddr.un.sun_path) - 1)
+ if (l >= sizeof(a->sockaddr.un.sun_path) - 1) /* Note that we refuse non-NUL-terminated sockets here
+ * when parsing, even though abstract namespace sockets
+ * explicitly allow embedded NUL bytes and don't consider
+ * them special. But it's simply annoying to debug such
+ * sockets. */
return -EINVAL;
a->sockaddr.un.sun_family = AF_UNIX;
@@ -125,7 +136,10 @@ int socket_address_parse(SocketAddress *a, const char *s) {
if (r < 0)
return r;
- n = strndupa(cid_start, e - cid_start);
+ n = strndup(cid_start, e - cid_start);
+ if (!n)
+ return -ENOMEM;
+
if (!isempty(n)) {
r = safe_atou(n, &a->sockaddr.vm.svm_cid);
if (r < 0)
@@ -146,7 +160,9 @@ int socket_address_parse(SocketAddress *a, const char *s) {
if (r < 0)
return r;
- n = strndupa(s, e-s);
+ n = strndup(s, e-s);
+ if (!n)
+ return -ENOMEM;
/* IPv4 in w.x.y.z:p notation? */
r = inet_pton(AF_INET, n, &a->sockaddr.in.sin_addr);
@@ -246,9 +262,12 @@ int socket_address_parse_netlink(SocketAddress *a, const char *s) {
return 0;
}
-int socket_address_verify(const SocketAddress *a) {
+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:
@@ -278,19 +297,29 @@ int socket_address_verify(const SocketAddress *a) {
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)) {
-
- 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) &&
+ 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 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;
}
}
@@ -329,7 +358,10 @@ int socket_address_print(const SocketAddress *a, char **ret) {
assert(a);
assert(ret);
- r = socket_address_verify(a);
+ 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;
@@ -362,8 +394,8 @@ bool socket_address_equal(const SocketAddress *a, const SocketAddress *b) {
assert(b);
/* Invalid addresses are unequal to all */
- if (socket_address_verify(a) < 0 ||
- socket_address_verify(b) < 0)
+ if (socket_address_verify(a, false) < 0 ||
+ socket_address_verify(b, false) < 0)
return false;
if (a->type != b->type)
@@ -474,6 +506,10 @@ const char* socket_address_get_path(const SocketAddress *a) {
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;
}
@@ -543,7 +579,13 @@ int sockaddr_port(const struct sockaddr *_sa, unsigned *ret_port) {
}
}
-int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_ipv6, bool include_port, char **ret) {
+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;
@@ -614,42 +656,51 @@ int sockaddr_pretty(const struct sockaddr *_sa, socklen_t salen, bool translate_
}
case AF_UNIX:
- if (salen <= offsetof(struct sockaddr_un, sun_path)) {
+ 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>");
- 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;
+ 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[0] = '@';
- memcpy(p+1, sa->un.sun_path+1, sizeof(sa->un.sun_path)-1);
- p[sizeof(sa->un.sun_path)] = 0;
+ p = strjoin("@", e);
+ } else {
+ if (path[path_len - 1] == '\0')
+ /* We expect a terminating NUL and don't print it */
+ path_len --;
- } else {
- p = strndup(sa->un.sun_path, sizeof(sa->un.sun_path));
- if (!p)
- return -ENOMEM;
+ p = cescape_length(path, path_len);
+ }
}
+ if (!p)
+ return -ENOMEM;
break;
case AF_VSOCK:
- if (include_port)
- r = asprintf(&p,
- "vsock:%u:%u",
- sa->vm.svm_cid,
- sa->vm.svm_port);
- else
+ 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;
@@ -739,21 +790,6 @@ int socknameinfo_pretty(union sockaddr_union *sa, socklen_t salen, char **_ret)
return 0;
}
-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",
@@ -826,10 +862,11 @@ int fd_inc_sndbuf(int fd, size_t n) {
/* 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;
+ if (setsockopt_int(fd, SOL_SOCKET, SO_SNDBUF, n) < 0) {
+ r = setsockopt_int(fd, SOL_SOCKET, SO_SNDBUFFORCE, n);
+ if (r < 0)
+ return r;
+ }
return 1;
}
@@ -844,10 +881,12 @@ int fd_inc_rcvbuf(int fd, size_t n) {
/* 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;
+ if (setsockopt_int(fd, SOL_SOCKET, SO_RCVBUF, n) < 0) {
+ r = setsockopt_int(fd, SOL_SOCKET, SO_RCVBUFFORCE, n);
+ if (r < 0)
+ return r;
+ }
+
return 1;
}
@@ -1003,9 +1042,10 @@ int getpeergroups(int fd, gid_t **ret) {
return (int) n;
}
-int send_one_fd_sa(
+ssize_t send_one_fd_iov_sa(
int transport_fd,
int fd,
+ struct iovec *iov, size_t iovlen,
const struct sockaddr *sa, socklen_t len,
int flags) {
@@ -1016,28 +1056,58 @@ int send_one_fd_sa(
struct msghdr mh = {
.msg_name = (struct sockaddr*) sa,
.msg_namelen = len,
- .msg_control = &control,
- .msg_controllen = sizeof(control),
+ .msg_iov = iov,
+ .msg_iovlen = iovlen,
};
- struct cmsghdr *cmsg;
+ ssize_t k;
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));
+ /*
+ * 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_controllen = CMSG_SPACE(sizeof(int));
- if (sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags) < 0)
- return -errno;
+ mh.msg_control = &control;
+ mh.msg_controllen = sizeof(control);
- return 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));
+ }
+ k = sendmsg(transport_fd, &mh, MSG_NOSIGNAL | flags);
+ if (k < 0)
+ return (ssize_t) -errno;
+
+ return k;
}
-int receive_one_fd(int transport_fd, int flags) {
+int send_one_fd_sa(
+ int transport_fd,
+ int fd,
+ const struct sockaddr *sa, socklen_t len,
+ int flags) {
+
+ assert(fd >= 0);
+
+ return (int) send_one_fd_iov_sa(transport_fd, fd, NULL, 0, sa, len, flags);
+}
+
+ssize_t receive_one_fd_iov(
+ int transport_fd,
+ struct iovec *iov, size_t iovlen,
+ int flags,
+ int *ret_fd) {
+
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(int))];
@@ -1045,10 +1115,14 @@ int receive_one_fd(int transport_fd, int flags) {
struct msghdr mh = {
.msg_control = &control,
.msg_controllen = sizeof(control),
+ .msg_iov = iov,
+ .msg_iovlen = iovlen,
};
struct cmsghdr *cmsg, *found = NULL;
+ ssize_t k;
assert(transport_fd >= 0);
+ assert(ret_fd);
/*
* Receive a single FD via @transport_fd. We don't care for
@@ -1058,8 +1132,9 @@ int receive_one_fd(int transport_fd, int flags) {
* combination with send_one_fd().
*/
- if (recvmsg(transport_fd, &mh, MSG_CMSG_CLOEXEC | flags) < 0)
- return -errno;
+ k = recvmsg(transport_fd, &mh, MSG_CMSG_CLOEXEC | flags);
+ if (k < 0)
+ return (ssize_t) -errno;
CMSG_FOREACH(cmsg, &mh) {
if (cmsg->cmsg_level == SOL_SOCKET &&
@@ -1071,12 +1146,33 @@ int receive_one_fd(int transport_fd, int flags) {
}
}
- if (!found) {
+ if (!found)
cmsg_close_all(&mh);
+
+ /* If didn't receive an FD or any data, return an error. */
+ if (k == 0 && !found)
return -EIO;
- }
- return *(int*) CMSG_DATA(found);
+ if (found)
+ *ret_fd = *(int*) CMSG_DATA(found);
+ else
+ *ret_fd = -1;
+
+ return k;
+}
+
+int receive_one_fd(int transport_fd, int flags) {
+ int fd;
+ ssize_t k;
+
+ k = receive_one_fd_iov(transport_fd, NULL, 0, flags, &fd);
+ if (k == 0)
+ return fd;
+
+ /* k must be negative, since receive_one_fd_iov() only returns
+ * a positive value if data was received through the iov. */
+ assert(k < 0);
+ return (int) k;
}
ssize_t next_datagram_size_fd(int fd) {
@@ -1181,3 +1277,71 @@ int socket_ioctl_fd(void) {
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 == 0)
+ return -EINVAL;
+ if (!IN_SET(path[0], '/', '@'))
+ return -EINVAL;
+ if (path[1] == 0)
+ return -EINVAL;
+
+ /* Don't allow paths larger than the space in sockaddr_un. Note that we are a tiny bit more restrictive than
+ * the kernel is: we insist on NUL termination (both for abstract namespace and regular file system socket
+ * addresses!), which the kernel doesn't. We do this to reduce chance of incompatibility with other apps that
+ * do not expect non-NUL terminated file system path*/
+ if (l+1 > sizeof(ret->sun_path))
+ return -EINVAL;
+
+ *ret = (struct sockaddr_un) {
+ .sun_family = AF_UNIX,
+ };
+
+ if (path[0] == '@') {
+ /* Abstract namespace socket */
+ memcpy(ret->sun_path + 1, path + 1, l); /* copy *with* trailing NUL byte */
+ return (int) (offsetof(struct sockaddr_un, sun_path) + l); /* 🔥 *don't* 🔥 include trailing NUL in size */
+
+ } else {
+ assert(path[0] == '/');
+
+ /* File system socket */
+ memcpy(ret->sun_path, path, l + 1); /* copy *with* trailing NUL byte */
+ return (int) (offsetof(struct sockaddr_un, sun_path) + l + 1); /* include trailing NUL in size */
+ }
+}
View Lorry Controller Status