#include "first.h"

#include "network.h"
#include "base.h"
#include "fdevent.h"
#include "log.h"
#include "connections.h"
#include "plugin.h"
#include "sock_addr.h"

#include "network_write.h"
#include "sys-socket.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

void
network_accept_tcp_nagle_disable (const int fd)
{
    static int noinherit_tcpnodelay = -1;
    int opt;

    if (!noinherit_tcpnodelay) /* TCP_NODELAY inherited from listen socket */
        return;

    if (noinherit_tcpnodelay < 0) {
        socklen_t optlen = sizeof(opt);
        if (0 == getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen)) {
            noinherit_tcpnodelay = !opt;
            if (opt)           /* TCP_NODELAY inherited from listen socket */
                return;
        }
    }

    opt = 1;
    (void)setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt));
}

static handler_t network_server_handle_fdevent(void *context, int revents) {
	server_socket * const srv_socket = (server_socket *)context;
	server * const srv = srv_socket->srv;
	connection *con;
	int loops;

	if (0 == (revents & FDEVENT_IN)) {
		log_error(srv->errh, __FILE__, __LINE__,
		  "strange event for server socket %d %d", srv_socket->fd, revents);
		return HANDLER_ERROR;
	}

	/* accept()s at most 100 connections directly
	 *
	 * we jump out after 100 to give the waiting connections a chance */
	if (srv->conns.used >= srv->max_conns) return HANDLER_GO_ON;
	loops = (int)(srv->max_conns - srv->conns.used + 1);
	if (loops > 100) loops = 101;

	while (--loops && NULL != (con = connection_accept(srv, srv_socket)))
		connection_state_machine(con);

	return HANDLER_GO_ON;
}

static void network_host_normalize_addr_str(buffer *host, sock_addr *addr) {
    buffer_clear(host);
    sock_addr_stringify_append_buffer(host, addr);
}

static int network_host_parse_addr(server *srv, sock_addr *addr, socklen_t *addr_len, buffer *host, int use_ipv6) {
    char *h;
    char *colon = NULL;
    const char *chost;
    sa_family_t family = use_ipv6 ? AF_INET6 : AF_INET;
    unsigned int port = srv->srvconf.port;
    if (buffer_string_is_empty(host)) {
        log_error(srv->errh, __FILE__, __LINE__,
          "value of $SERVER[\"socket\"] must not be empty");
        return -1;
    }
    h = host->ptr;
    if (h[0] == '/') {
      #ifdef HAVE_SYS_UN_H
        return (1 ==
                sock_addr_from_str_hints(addr,addr_len,h,AF_UNIX,0,srv->errh))
          ? 0
          : -1;
      #else
        log_error(srv, __FILE__, __LINE__,
          "ERROR: Unix Domain sockets are not supported.");
        return -1;
      #endif
    }
    buffer * const tb = srv->tmp_buf;
    buffer_copy_buffer(tb, host);
    h = tb->ptr;
    if (h[0] == '[') {
        family = AF_INET6;
        if ((h = strchr(h, ']'))) {
            *h++ = '\0';
            if (*h == ':') colon = h;
        } /*(else should not happen; validated in configparser.y)*/
        h = tb->ptr+1;
    }
    else {
        colon = strrchr(h, ':');
    }
    if (colon) {
        *colon++ = '\0';
        port = (unsigned int)strtol(colon, NULL, 10);
        if (port == 0 || port > 65535) {
            log_error(srv->errh, __FILE__, __LINE__,
              "port not set or out of range: %u", port);
            return -1;
        }
    }
    chost = *h ? h : family == AF_INET ? "0.0.0.0" : "::";
    if (1 !=
        sock_addr_from_str_hints(addr,addr_len,chost,family,port,srv->errh)) {
        return -1;
    }
    return 0;
}

static void network_srv_sockets_append(server *srv, server_socket *srv_socket) {
	if (srv->srv_sockets.used == srv->srv_sockets.size) {
		srv->srv_sockets.size += 4;
		srv->srv_sockets.ptr = realloc(srv->srv_sockets.ptr, srv->srv_sockets.size * sizeof(server_socket*));
		force_assert(NULL != srv->srv_sockets.ptr);
	}

	srv->srv_sockets.ptr[srv->srv_sockets.used++] = srv_socket;
}

typedef struct {
    /* global or per-socket config; not patched per connection */
    int listen_backlog;
    unsigned char ssl_enabled;
    unsigned char use_ipv6;
    unsigned char set_v6only; /* set_v6only is only a temporary option */
    unsigned char defer_accept;
    const buffer *socket_perms;
    const buffer *bsd_accept_filter;
} network_socket_config;

typedef struct {
    PLUGIN_DATA;
    network_socket_config defaults;
    network_socket_config conf;
} network_plugin_data;

static void network_merge_config_cpv(network_socket_config * const pconf, const config_plugin_value_t * const cpv) {
    switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
      case 0: /* ssl.engine */
        pconf->ssl_enabled = (0 != cpv->v.u);
        break;
      case 1: /* server.listen-backlog */
        pconf->listen_backlog = (int)cpv->v.u;
        break;
      case 2: /* server.socket-perms */
        pconf->socket_perms = cpv->v.b;
        break;
      case 3: /* server.bsd-accept-filter */
        pconf->bsd_accept_filter = cpv->v.b;
        break;
      case 4: /* server.defer-accept */
        pconf->defer_accept = (0 != cpv->v.u);
        break;
      case 5: /* server.use-ipv6 */
        pconf->use_ipv6 = (0 != cpv->v.u);
        break;
      case 6: /* server.set-v6only */
        pconf->set_v6only = (0 != cpv->v.u);
        break;
      default:/* should not happen */
        return;
    }
}

static void network_merge_config(network_socket_config * const pconf, const config_plugin_value_t *cpv) {
    do {
        network_merge_config_cpv(pconf, cpv);
    } while ((++cpv)->k_id != -1);
}

static int network_server_init(server *srv, network_socket_config *s, buffer *host_token, size_t sidx, int stdin_fd) {
	server_socket *srv_socket;
	const char *host;
	socklen_t addr_len = sizeof(sock_addr);
	sock_addr addr;
	int family = 0;
	int set_v6only = 0;

	if (buffer_string_is_empty(host_token)) {
		log_error(srv->errh, __FILE__, __LINE__,
		  "value of $SERVER[\"socket\"] must not be empty");
		return -1;
	}

	/* check if we already know this socket, and if yes, don't init it
	 * (optimization: check strings here to filter out exact matches;
	 *  binary addresses are matched further below) */
	for (uint32_t i = 0; i < srv->srv_sockets.used; ++i) {
		if (buffer_is_equal(srv->srv_sockets.ptr[i]->srv_token, host_token)) {
			return 0;
		}
	}

	host = host_token->ptr;
	if ((s->use_ipv6 && (*host == '\0' || *host == ':')) || (host[0] == '[' && host[1] == ']')) {
		log_error(srv->errh, __FILE__, __LINE__,
		  "warning: please use server.use-ipv6 only for hostnames, "
		  "not without server.bind / empty address; your config will "
		  "break if the kernel default for IPV6_V6ONLY changes");
	}
	if (*host == '[') s->use_ipv6 = 1;

	memset(&addr, 0, sizeof(addr));
	if (-1 != stdin_fd) {
		if (-1 == getsockname(stdin_fd, (struct sockaddr *)&addr, &addr_len)) {
			log_perror(srv->errh, __FILE__, __LINE__, "getsockname()");
			return -1;
		}
	} else if (0 != network_host_parse_addr(srv, &addr, &addr_len, host_token, s->use_ipv6)) {
		return -1;
	}

	family = sock_addr_get_family(&addr);

      #ifdef HAVE_IPV6
	if (*host != '\0' && AF_INET6 == family) {
		if (s->set_v6only) {
			set_v6only = 1;
		} else {
			log_error(srv->errh, __FILE__, __LINE__,
			  "warning: server.set-v6only will be removed soon, "
			  "update your config to have different sockets for ipv4 and ipv6");
		}
	}
      #endif

	network_host_normalize_addr_str(host_token, &addr);
	host = host_token->ptr;

	if (srv->srvconf.preflight_check) {
		return 0;
	}

	/* check if we already know this socket (after potential DNS resolution), and if yes, don't init it */
	for (uint32_t i = 0; i < srv->srv_sockets.used; ++i) {
		if (0 == memcmp(&srv->srv_sockets.ptr[i]->addr, &addr, sizeof(addr))) {
			return 0;
		}
	}

	srv_socket = calloc(1, sizeof(*srv_socket));
	force_assert(NULL != srv_socket);
	memcpy(&srv_socket->addr, &addr, addr_len);
	srv_socket->fd = -1;
	srv_socket->sidx = sidx;
	srv_socket->is_ssl = s->ssl_enabled;
	srv_socket->srv = srv;
	srv_socket->srv_token = buffer_init_buffer(host_token);

	network_srv_sockets_append(srv, srv_socket);

	if (srv->sockets_disabled) { /* lighttpd -1 (one-shot mode) */
		return 0;
	}

	if (srv->srvconf.systemd_socket_activation) {
		for (uint32_t i = 0; i < srv->srv_sockets_inherited.used; ++i) {
			if (0 != memcmp(&srv->srv_sockets_inherited.ptr[i]->addr, &srv_socket->addr, addr_len)) continue;
			if ((unsigned short)~0u == srv->srv_sockets_inherited.ptr[i]->sidx) {
				srv->srv_sockets_inherited.ptr[i]->sidx = sidx;
			}
			stdin_fd = srv->srv_sockets_inherited.ptr[i]->fd;
			break;
		}
	}

	if (-1 != stdin_fd) {
		srv_socket->fd = stdin_fd;
		if (-1 == fdevent_fcntl_set_nb_cloexec(stdin_fd)) {
			log_perror(srv->errh, __FILE__, __LINE__, "fcntl");
			return -1;
		}
	} else
#ifdef HAVE_SYS_UN_H
	if (AF_UNIX == family) {
		/* check if the socket exists and try to connect to it. */
		force_assert(host); /*(static analysis hint)*/
		if (-1 == (srv_socket->fd = fdevent_socket_cloexec(AF_UNIX, SOCK_STREAM, 0))) {
			log_perror(srv->errh, __FILE__, __LINE__, "socket");
			return -1;
		}
		if (0 == connect(srv_socket->fd, (struct sockaddr *) &(srv_socket->addr), addr_len)) {
			log_error(srv->errh, __FILE__, __LINE__,
			  "server socket is still in use: %s", host);
			return -1;
		}

		/* connect failed */
		switch(errno) {
		case ECONNREFUSED:
			unlink(host);
			break;
		case ENOENT:
			break;
		default:
			log_perror(srv->errh, __FILE__, __LINE__,
			  "testing socket failed: %s", host);
			return -1;
		}

		if (-1 == fdevent_fcntl_set_nb(srv_socket->fd)) {
			log_perror(srv->errh, __FILE__, __LINE__, "fcntl");
			return -1;
		}
	} else
#endif
	{
		if (-1 == (srv_socket->fd = fdevent_socket_nb_cloexec(family, SOCK_STREAM, IPPROTO_TCP))) {
			log_perror(srv->errh, __FILE__, __LINE__, "socket");
			return -1;
		}
	}

#ifdef HAVE_IPV6
		if (set_v6only && -1 == stdin_fd) {
				int val = 1;
				if (-1 == setsockopt(srv_socket->fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val))) {
					log_perror(srv->errh, __FILE__, __LINE__, "setsockopt(IPV6_V6ONLY)");
					return -1;
				}
		}
#endif

	/* */
	srv->cur_fds = srv_socket->fd;

	if (fdevent_set_so_reuseaddr(srv_socket->fd, 1) < 0) {
		log_perror(srv->errh, __FILE__, __LINE__, "setsockopt(SO_REUSEADDR)");
		return -1;
	}

	if (family != AF_UNIX) {
		if (fdevent_set_tcp_nodelay(srv_socket->fd, 1) < 0) {
			log_perror(srv->errh, __FILE__, __LINE__, "setsockopt(TCP_NODELAY)");
			return -1;
		}
	}

	if (-1 != stdin_fd) { } else
	if (0 != bind(srv_socket->fd, (struct sockaddr *) &(srv_socket->addr), addr_len)) {
		log_perror(srv->errh, __FILE__, __LINE__,
		  "can't bind to socket: %s", host);
		return -1;
	}

	if (-1 != stdin_fd) { } else
	if (AF_UNIX == family && !buffer_string_is_empty(s->socket_perms)) {
		mode_t m = 0;
		for (char *str = s->socket_perms->ptr; *str; ++str) {
			m <<= 3;
			m |= (*str - '0');
		}
		if (0 != m && -1 == chmod(host, m)) {
			log_perror(srv->errh, __FILE__, __LINE__,
			  "chmod(\"%s\", %s)", host, s->socket_perms->ptr);
		}
	}

	if (-1 != stdin_fd) { } else
	if (-1 == listen(srv_socket->fd, s->listen_backlog)) {
		log_perror(srv->errh, __FILE__, __LINE__, "listen");
		return -1;
	}

	if (s->ssl_enabled) {
#ifdef TCP_DEFER_ACCEPT
	} else if (s->defer_accept) {
		int v = s->defer_accept;
		if (-1 == setsockopt(srv_socket->fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &v, sizeof(v))) {
			log_perror(srv->errh, __FILE__, __LINE__, "can't set TCP_DEFER_ACCEPT");
		}
#endif
#if defined(__FreeBSD__) || defined(__NetBSD__) \
 || defined(__OpenBSD__) || defined(__DragonFly__)
	} else if (!buffer_is_empty(s->bsd_accept_filter)
		   && (buffer_is_equal_string(s->bsd_accept_filter, CONST_STR_LEN("httpready"))
			|| buffer_is_equal_string(s->bsd_accept_filter, CONST_STR_LEN("dataready")))) {
#ifdef SO_ACCEPTFILTER
		/* FreeBSD accf_http filter */
		struct accept_filter_arg afa;
		memset(&afa, 0, sizeof(afa));
		strncpy(afa.af_name, s->bsd_accept_filter->ptr, sizeof(afa.af_name));
		if (setsockopt(srv_socket->fd, SOL_SOCKET, SO_ACCEPTFILTER, &afa, sizeof(afa)) < 0) {
			if (errno != ENOENT) {
				log_perror(srv->errh, __FILE__, __LINE__,
				  "can't set accept-filter '%s'", s->bsd_accept_filter->ptr);
			}
		}
#endif
#endif
	}

	return 0;
}

int network_close(server *srv) {
	for (uint32_t i = 0; i < srv->srv_sockets.used; ++i) {
		server_socket *srv_socket = srv->srv_sockets.ptr[i];
		if (srv_socket->fd != -1) {
			network_unregister_sock(srv, srv_socket);
			close(srv_socket->fd);
		}

		buffer_free(srv_socket->srv_token);

		free(srv_socket);
	}

	free(srv->srv_sockets.ptr);
	srv->srv_sockets.ptr = NULL;
	srv->srv_sockets.used = 0;
	srv->srv_sockets.size = 0;

	for (uint32_t i = 0; i < srv->srv_sockets_inherited.used; ++i) {
		server_socket *srv_socket = srv->srv_sockets_inherited.ptr[i];
		if (srv_socket->fd != -1 && srv_socket->sidx != (unsigned short)~0u) {
			close(srv_socket->fd);
		}

		buffer_free(srv_socket->srv_token);

		free(srv_socket);
	}

	free(srv->srv_sockets_inherited.ptr);
	srv->srv_sockets_inherited.ptr = NULL;
	srv->srv_sockets_inherited.used = 0;
	srv->srv_sockets_inherited.size = 0;

	return 0;
}

static int network_socket_activation_nfds(server *srv, network_socket_config *s, int nfds) {
    buffer *host = buffer_init();
    socklen_t addr_len;
    sock_addr addr;
    int rc = 0;
    nfds += 3; /* #define SD_LISTEN_FDS_START 3 */
    for (int fd = 3; fd < nfds; ++fd) {
        addr_len = sizeof(sock_addr);
        if (-1 == (rc = getsockname(fd, (struct sockaddr *)&addr, &addr_len))) {
            log_perror(srv->errh, __FILE__, __LINE__,
              "socket activation getsockname()");
            break;
        }
        network_host_normalize_addr_str(host, &addr);
        rc = network_server_init(srv, s, host, 0, fd);
        if (0 != rc) break;
        srv->srv_sockets.ptr[srv->srv_sockets.used-1]->sidx = (unsigned short)~0u;
    }
    buffer_free(host);
    memcpy(&srv->srv_sockets_inherited, &srv->srv_sockets, sizeof(server_socket_array));
    memset(&srv->srv_sockets, 0, sizeof(server_socket_array));
    return rc;
}

static int network_socket_activation_from_env(server *srv, network_socket_config *s) {
    char *listen_pid = getenv("LISTEN_PID");
    char *listen_fds = getenv("LISTEN_FDS");
    pid_t lpid = listen_pid ? (pid_t)strtoul(listen_pid,NULL,10) : 0;
    int nfds = listen_fds ? atoi(listen_fds) : 0;
    int rc = (lpid == getpid() && nfds > 0)
      ? network_socket_activation_nfds(srv, s, nfds)
      : 0;
    unsetenv("LISTEN_PID");
    unsetenv("LISTEN_FDS");
    unsetenv("LISTEN_FDNAMES");
    /*(upon graceful restart, unsetenv will result in no-op above)*/
    return rc;
}

int network_init(server *srv, int stdin_fd) {
    /*(network params used during setup (from $SERVER["socket"] condition))*/
    static const config_plugin_keys_t cpk[] = {
      { CONST_STR_LEN("ssl.engine"),
        T_CONFIG_BOOL,
        T_CONFIG_SCOPE_CONNECTION }
     ,{ CONST_STR_LEN("server.listen-backlog"),
        T_CONFIG_INT,
        T_CONFIG_SCOPE_CONNECTION }
     ,{ CONST_STR_LEN("server.socket-perms"),
        T_CONFIG_STRING,
        T_CONFIG_SCOPE_CONNECTION }
     ,{ CONST_STR_LEN("server.bsd-accept-filter"),
        T_CONFIG_STRING,
        T_CONFIG_SCOPE_CONNECTION }
     ,{ CONST_STR_LEN("server.defer-accept"),
        T_CONFIG_BOOL,
        T_CONFIG_SCOPE_CONNECTION }
     ,{ CONST_STR_LEN("server.use-ipv6"),
        T_CONFIG_BOOL,
        T_CONFIG_SCOPE_CONNECTION }
     ,{ CONST_STR_LEN("server.set-v6only"),
        T_CONFIG_BOOL,
        T_CONFIG_SCOPE_CONNECTION }
     ,{ NULL, 0,
        T_CONFIG_UNSET,
        T_CONFIG_SCOPE_UNSET }
    };

  #ifdef __WIN32
    WSADATA wsaData;
    WORD wVersionRequested = MAKEWORD(2, 2);
    if (0 != WSAStartup(wVersionRequested, &wsaData)) {
        /* Tell the user that we could not find a usable WinSock DLL */
        return -1;
    }
  #endif

    if (0 != network_write_init(srv)) return -1;

    network_plugin_data np;
    memset(&np, 0, sizeof(network_plugin_data));
    network_plugin_data *p = &np;

    if (!config_plugin_values_init(srv, p, cpk, "network"))
        return HANDLER_ERROR;

    p->defaults.listen_backlog = 1024;
    p->defaults.defer_accept = 0;
    p->defaults.use_ipv6 = 0;
    p->defaults.set_v6only = 1;

    /* initialize p->defaults from global config context */
    if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
        const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
        if (-1 != cpv->k_id)
            network_merge_config(&p->defaults, cpv);
    }

    int rc = 0;
    do {

        if (srv->srvconf.systemd_socket_activation) {
            for (uint32_t i = 0; i < srv->srv_sockets_inherited.used; ++i) {
                srv->srv_sockets_inherited.ptr[i]->sidx = (unsigned short)~0u;
            }
            rc = network_socket_activation_from_env(srv, &p->defaults);
            if (0 != rc) break;
            if (0 == srv->srv_sockets_inherited.used) {
                srv->srvconf.systemd_socket_activation = 0;
            }
        }

        /* process srv->srvconf.bindhost
         * (skip if systemd socket activation is enabled and bindhost is empty;
         *  do not additionally listen on "*") */
        if (!srv->srvconf.systemd_socket_activation
            || !buffer_string_is_empty(srv->srvconf.bindhost)) {
            buffer *b = buffer_init();
            buffer_copy_buffer(b, srv->srvconf.bindhost);
            if (b->ptr[0] != '/') { /*(skip adding port if unix socket path)*/
                buffer_append_string_len(b, CONST_STR_LEN(":"));
                buffer_append_int(b, srv->srvconf.port);
            }

            rc = (-1 == stdin_fd || 0 == srv->srv_sockets.used)
              ? network_server_init(srv, &p->defaults, b, 0, stdin_fd)
              : close(stdin_fd);/*(graceful restart listening to "/dev/stdin")*/
            buffer_free(b);
            if (0 != rc) break;
        }

        /* check for $SERVER["socket"] */
        for (uint32_t i = 1; i < srv->config_context->used; ++i) {
            config_cond_info cfginfo;
            config_get_config_cond_info(&cfginfo, i);
            if (COMP_SERVER_SOCKET != cfginfo.comp) continue;/* not our stage */

            buffer *host_token;
            *(const buffer **)&host_token = cfginfo.string;
            /*(cfginfo.string is modified during config)*/

            memcpy(&p->conf, &p->defaults, sizeof(network_socket_config));
            for (int j = !p->cvlist[0].v.u2[1]; j < p->nconfig; ++j) {
                if ((int)i != p->cvlist[j].k_id) continue;
                const config_plugin_value_t *cpv =
                  p->cvlist + p->cvlist[j].v.u2[0];
                network_merge_config(&p->conf, cpv);
                break;
            }

            if (cfginfo.cond == CONFIG_COND_EQ) {
                rc = network_server_init(srv, &p->conf, host_token, i, -1);
                if (0 != rc) break;
            }
            else if (cfginfo.cond == CONFIG_COND_NE) {
                socklen_t addr_len = sizeof(sock_addr);
                sock_addr addr;
                rc = network_host_parse_addr(srv, &addr, &addr_len,
                                             host_token, p->conf.use_ipv6);
                if (0 != rc) break;
                network_host_normalize_addr_str(host_token, &addr);
            }
        }
        if (0 != rc) break;

        if (srv->srvconf.systemd_socket_activation) {
            /* activate any inherited sockets not explicitly listed in config */
            server_socket *srv_socket;
            for (uint32_t i = 0; i < srv->srv_sockets_inherited.used; ++i) {
                    if ((unsigned short)~0u
                        != srv->srv_sockets_inherited.ptr[i]->sidx)
                        continue;
                    srv->srv_sockets_inherited.ptr[i]->sidx = 0;
                srv_socket = calloc(1, sizeof(server_socket));
                force_assert(NULL != srv_socket);
                memcpy(srv_socket, srv->srv_sockets_inherited.ptr[i],
                       sizeof(server_socket));
                network_srv_sockets_append(srv, srv_socket);
            }
        }

    } while (0);

    free(p->cvlist);
    return rc;
}

void network_unregister_sock(server *srv, server_socket *srv_socket) {
	fdnode *fdn = srv_socket->fdn;
	if (NULL == fdn) return;
	fdevent_fdnode_event_del(srv->ev, fdn);
	fdevent_unregister(srv->ev, fdn->fd);
	srv_socket->fdn = NULL;
}

int network_register_fdevents(server *srv) {
	if (-1 == fdevent_reset(srv->ev)) {
		return -1;
	}

	if (srv->sockets_disabled) return 0; /* lighttpd -1 (one-shot mode) */

	/* register fdevents after reset */
	for (uint32_t i = 0; i < srv->srv_sockets.used; ++i) {
		server_socket *srv_socket = srv->srv_sockets.ptr[i];

		srv_socket->fdn = fdevent_register(srv->ev, srv_socket->fd, network_server_handle_fdevent, srv_socket);
		fdevent_fdnode_event_set(srv->ev, srv_socket->fdn, FDEVENT_IN);
	}
	return 0;
}