/* SPDX-License-Identifier: LGPL-2.1+ */

#include <errno.h>

#include <netinet/in.h>

#include <stdbool.h>

#include <stddef.h>

#include <string.h>

#include <sys/socket.h>

#include <sys/un.h>

#include <unistd.h>

#include "alloc-util.h"

#include "fd-util.h"

#include "fs-util.h"

#include "log.h"

#include "macro.h"

#include "missing.h"

#include "mkdir.h"

#include "selinux-util.h"

#include "socket-util.h"

#include "umask-util.h"

int socket_address_listen(

                const SocketAddress *a,

                int flags,

                int backlog,

                SocketAddressBindIPv6Only only,

                const char *bind_to_device,

                bool reuse_port,

                bool free_bind,

                bool transparent,

                mode_t directory_mode,

                mode_t socket_mode,

                const char *label) {

        _cleanup_close_ int fd = -1;

        const char *p;

        int r;

        assert(a);

        r = socket_address_verify(a, true);

        if (r < 0)

                return r;

        if (socket_address_family(a) == AF_INET6 && !socket_ipv6_is_supported())

                return -EAFNOSUPPORT;

        if (label) {

                r = mac_selinux_create_socket_prepare(label);

                if (r < 0)

                        return r;

        }

        fd = socket(socket_address_family(a), a->type | flags, a->protocol);

        r = fd < 0 ? -errno : 0;

        if (label)

                mac_selinux_create_socket_clear();

        if (r < 0)

                return r;

        if (socket_address_family(a) == AF_INET6 && only != SOCKET_ADDRESS_DEFAULT) {

                r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_V6ONLY, only == SOCKET_ADDRESS_IPV6_ONLY);

                if (r < 0)

                        return r;

        }

        if (IN_SET(socket_address_family(a), AF_INET, AF_INET6)) {

                if (bind_to_device) {

                        r = socket_bind_to_ifname(fd, bind_to_device);

                        if (r < 0)

                                return r;

                }

                if (reuse_port) {

                        r = setsockopt_int(fd, SOL_SOCKET, SO_REUSEPORT, true);

                        if (r < 0)

                                log_warning_errno(r, "SO_REUSEPORT failed: %m");

                }

                if (free_bind) {

                        r = setsockopt_int(fd, IPPROTO_IP, IP_FREEBIND, true);

                        if (r < 0)

                                log_warning_errno(r, "IP_FREEBIND failed: %m");

                }

                if (transparent) {

                        r = setsockopt_int(fd, IPPROTO_IP, IP_TRANSPARENT, true);

                        if (r < 0)

                                log_warning_errno(r, "IP_TRANSPARENT failed: %m");

                }

        }

        r = setsockopt_int(fd, SOL_SOCKET, SO_REUSEADDR, true);

        if (r < 0)

                return r;

        p = socket_address_get_path(a);

        if (p) {

                /* Create parents */

                (void) mkdir_parents_label(p, directory_mode);

                /* Enforce the right access mode for the socket */

                RUN_WITH_UMASK(~socket_mode) {

                        r = mac_selinux_bind(fd, &a->sockaddr.sa, a->size);

                        if (r == -EADDRINUSE) {

                                /* Unlink and try again */

                                if (unlink(p) < 0)

                                        return r; /* didn't work, return original error */

                                r = mac_selinux_bind(fd, &a->sockaddr.sa, a->size);

                        }

                        if (r < 0)

                                return r;

                }

        } else {

                if (bind(fd, &a->sockaddr.sa, a->size) < 0)

                        return -errno;

        }

        if (socket_address_can_accept(a))

                if (listen(fd, backlog) < 0)

                        return -errno;

        /* Let's trigger an inotify event on the socket node, so that anyone waiting for this socket to be connectable

         * gets notified */

        if (p)

                (void) touch(p);

        r = fd;

        fd = -1;

        return r;

}

int make_socket_fd(int log_level, const char* address, int type, int flags) {

        SocketAddress a;

        int fd, r;

        r = socket_address_parse(&a, address);

        if (r < 0)

                return log_error_errno(r, "Failed to parse socket address \"%s\": %m", address);

        a.type = type;

        fd = socket_address_listen(&a, type | flags, SOMAXCONN, SOCKET_ADDRESS_DEFAULT,

                                   NULL, false, false, false, 0755, 0644, NULL);

        if (fd < 0 || log_get_max_level() >= log_level) {

                _cleanup_free_ char *p = NULL;

                r = socket_address_print(&a, &p);

                if (r < 0)

                        return log_error_errno(r, "socket_address_print(): %m");

                if (fd < 0)

                        log_error_errno(fd, "Failed to listen on %s: %m", p);

                else

                        log_full(log_level, "Listening on %s", p);

        }

        return fd;

}