1 files changed, 183 insertions, 1 deletions

diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index 312512ba1d..684ac765f5 100644
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -23,20 +23,22 @@
 #include <errno.h>
 #include <net/if.h>
 #include <netdb.h>
+#include <netinet/ip.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/types.h>
 #include <unistd.h>
 
+#include "fd-util.h"
 #include "fileio.h"
 #include "formats-util.h"
 #include "macro.h"
 #include "missing.h"
 #include "path-util.h"
+#include "socket-util.h"
 #include "string-util.h"
 #include "util.h"
-#include "socket-util.h"
 
 int socket_address_parse(SocketAddress *a, const char *s) {
         char *e, *n;
@@ -749,3 +751,183 @@ bool sockaddr_equal(const union sockaddr_union *a, const union sockaddr_union *b
 
         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);
+
+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(int transport_fd, int 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;
+
+        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);
+}