src/shared/: split AF_UNIX/AF_VSOCK address parsing into src/basic/

We'll use it from libsystemd0 later, but AF_INET/6 requires some
netlink calls and thus the additional library dependency

src/basic/socket-util.c

@@ -1472,3 +1472,71 @@ int connect_unix_path(int fd, int dir_fd, const char *path) {
 
         return RET_NERRNO(connect(fd, &sa.sa, salen));
 }
+
+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_parse_vsock(SocketAddress *ret_address, const char *s) {
+        /* AF_VSOCK socket in vsock:cid:port notation */
+        _cleanup_free_ char *n = NULL;
+        char *e, *cid_start;
+        unsigned port, cid;
+        int r;
+
+        assert(ret_address);
+        assert(s);
+
+        cid_start = startswith(s, "vsock:");
+        if (!cid_start)
+                return -EPROTO;
+
+        e = strchr(cid_start, ':');
+        if (!e)
+                return -EINVAL;
+
+        r = safe_atou(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 = safe_atou(n, &cid);
+                if (r < 0)
+                        return r;
+        }
+
+        *ret_address = (SocketAddress) {
+                .sockaddr.vm = {
+                        .svm_cid = cid,
+                        .svm_family = AF_VSOCK,
+                        .svm_port = port,
+                },
+                .size = sizeof(struct sockaddr_vm),
+        };
+
+        return 0;
+}

src/basic/socket-util.h

@@ -336,3 +336,9 @@ int socket_get_mtu(int fd, int af, size_t *ret);
 #define UCRED_INVALID { .pid = 0, .uid = UID_INVALID, .gid = GID_INVALID }
 
 int connect_unix_path(int fd, int dir_fd, const char *path);
+
+/* Parses AF_UNIX and AF_VSOCK addresses. AF_INET[6] require some netlink calls, so it cannot be in
+ * src/basic/ and is done from 'socket_local_address from src/shared/. Return -EPROTO in case of
+ * protocol mismatch. */
+int socket_address_parse_unix(SocketAddress *ret_address, const char *s);
+int socket_address_parse_vsock(SocketAddress *ret_address, const char *s);