path: root/src/plugin.c

#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <errno.h>
#include <poll.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <rpcsvc/yp_prot.h>

#include <nspr.h>
#include <secport.h>
#include <plarenas.h>
#include <dirsrv/slapi-plugin.h>

#include "nis.h"
#include "plugin.h"
#include "portmap.h"
#include "schema.h"
#include "stream.h"

#define PACKAGE_VERSION "0.0"

/* the module initialization function */
static Slapi_PluginDesc
plugin_description = {
	.spd_id = "nis-plugin",
	.spd_vendor = "hamdingers.org",
	.spd_version = PACKAGE_VERSION,
	.spd_description = "NIS Service Plugin",
};

static void *
listener_thread(void *p)
{
	struct plugin_state *state = p;
	struct pollfd fds[4];
	int client, reqsize, i;
	char dgram[65536];
	struct sockaddr_storage client_addr;
	socklen_t client_addrlen;
	for (;;) {
		/* Set up for polling. */
		memset(&fds, 0, sizeof(fds));
		for (i = 0; i < state->n_listeners; i++) {
			fds[i].fd = state->listenfd[i];
			fds[i].events = POLLIN;
		}
		switch (poll(fds, state->n_listeners, -1) != -1) {
		case -1:
			return NULL;
			break;
		case 0:
			continue;
		default:
			/* Iterate over listening sockets with work for us. */
			for (i = 0; i < state->n_listeners; i++) {
				if ((fds[i].revents & POLLIN) == 0) {
					continue;
				}
				switch (state->sock_type[i]) {
				case SOCK_DGRAM:
					client_addrlen = sizeof(client_addr);
					reqsize = recvfrom(fds[i].fd,
							   dgram,
							   sizeof(dgram),
							   0,
							   (struct sockaddr *) &client_addr,
							   &client_addrlen);
					slapi_log_error(SLAPI_LOG_PLUGIN,
							plugin_description.spd_id,
							"datagram request\n");
					nis_process_request(state, fds[i].fd,
							    (struct sockaddr *)
							    &client_addr,
							    client_addrlen,
							    dgram, reqsize);
					break;
				case SOCK_STREAM:
					client = accept(fds[i].fd, NULL, NULL);
					if (client != -1) {
						slapi_log_error(SLAPI_LOG_PLUGIN,
								plugin_description.spd_id,
								"new stream request\n");
						stream_client_start(state,
								    client);
					}
					break;
				default:
					slapi_log_error(SLAPI_LOG_PLUGIN,
							plugin_description.spd_id,
							"unknown request\n");
					break;
				}
			}
		}
	}
	return state;
}

/* Start the plugin's work thread. */
static int
plugin_start(Slapi_PBlock *pb)
{
	struct plugin_state *state;
	const char *pname;
	int i, protocol;
	slapi_pblock_get(pb, SLAPI_PLUGIN_PRIVATE, &state);
	slapi_log_error(SLAPI_LOG_PLUGIN, "plugin_start",
			"plugin starting\n");
	/* Register the listener sockets with the portmapper. */
	if (state->resvport != -1) {
		for (i = 0; i < state->n_listeners; i++) {
			switch (state->sock_type[i]) {
			case SOCK_DGRAM:
				protocol = IPPROTO_UDP;
				pname = "UDP";
				break;
			case SOCK_STREAM:
				protocol = IPPROTO_TCP;
				pname = "TCP";
				break;
			default:
				protocol = IPPROTO_IP;
				pname = "IP";
				break;
			}
			if (protocol == IPPROTO_IP) {
				continue;
			}
			if (!portmap_register(state->resvport,
					      YPPROG, YPVERS, protocol,
					      state->listenport[i])) {
				slapi_log_error(SLAPI_LOG_PLUGIN,
						plugin_description.spd_id,
						"error registering %s service "
						"with portmap\n", pname);
			}
		}
	}
	/* Start a new listening thread to handle incoming traffic.  FIXME:
	 * switch to using NSPR's threading facilities. */
	if (pthread_create(&state->tid, NULL, &listener_thread, state) != 0) {
		slapi_log_error(SLAPI_LOG_PLUGIN,
				plugin_description.spd_id,
				"error starting listener thread\n");
		return -1;
	}
	slapi_log_error(SLAPI_LOG_PLUGIN, plugin_description.spd_id,
			"plugin startup completed\n");
	return 0;
}

/* Stop the plugin's work thread. */
static int
plugin_close(Slapi_PBlock *pb)
{
	struct plugin_state *state;
	slapi_pblock_get(pb, SLAPI_PLUGIN_PRIVATE, &state);
	if (state->resvport != -1) {
		/* Clear our registration with the portmapper. */
		portmap_unregister(state->resvport, YPPROG, YPVERS);
		close(state->resvport);
	}
	return 0;
}

static int
setup_listener_sockets(struct plugin_state **lstate)
{
	int sockfd = -1, err, i;
	struct plugin_state *state;
	PLArenaPool *arena = NULL;

	arena = PORT_NewArena(sizeof(double));
	if (arena == NULL) {
		goto failed;
	}
	state = PORT_ArenaZAlloc(arena, sizeof(*state));
	if (state == NULL) {
		goto failed;
	}
	state->arena = arena;

	/* Bind to a privileged port so that the portmapper will let us
	 * register after we've dropped to a non-root account.  We could reuse
	 * the datagram listening socket we'll create later. */
	state->resvport = socket(PF_INET, SOCK_DGRAM, 0);
	if (bindresvport(state->resvport, NULL) != 0) {
		slapi_log_error(SLAPI_LOG_PLUGIN,
				plugin_description.spd_id,
				"error setting up portmap client socket, %d\n",
				(int)getuid());
		close(state->resvport);
		state->resvport = -1;
	}

	/* Privileged port, datagram and stream, IPv4 and IPv6. */
	for (i = 0; i < 4; i++) {
		int sock_pf, sock_type, one = 1;
		struct sockaddr *addr;
		socklen_t addrlen;
		struct sockaddr_storage ss;
		struct sockaddr_in *addr4 = (struct sockaddr_in *) &ss;
		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) &ss;
		const char *sock_desc;
		u_int16_t *port;
		memset(&ss, 0, sizeof(ss));
		switch (i) {
		case 0:
			sock_pf = PF_INET;
			sock_type = SOCK_DGRAM;
			sock_desc = "udp";
			addr4->sin_family = AF_INET;
			port = &addr4->sin_port;
			break;
		case 1:
			sock_pf = PF_INET;
			sock_type = SOCK_STREAM;
			sock_desc = "tcp";
			addr4->sin_family = AF_INET;
			port = &addr4->sin_port;
			break;
		case 2:
			sock_pf = PF_INET6;
			sock_type = SOCK_DGRAM;
			sock_desc = "udp6";
			addr6->sin6_family = AF_INET6;
			port = &addr6->sin6_port;
			break;
		case 3:
			sock_pf = PF_INET6;
			sock_type = SOCK_STREAM;
			sock_desc = "tcp6";
			addr6->sin6_family = AF_INET6;
			port = &addr6->sin6_port;
			break;
		}
		sockfd = socket(sock_pf, sock_type, 0);
		if (sockfd == -1) {
			slapi_log_error(SLAPI_LOG_PLUGIN,
					plugin_description.spd_id,
					"error creating a %s socket\n",
					sock_desc);
			continue;
		}
		if (setsockopt(sockfd, IPPROTO_IP, SO_REUSEADDR,
			       &one, sizeof(one)) != 0) {
			slapi_log_error(SLAPI_LOG_PLUGIN,
					plugin_description.spd_id,
					"error marking %s socket for reuse\n",
					sock_desc);
		}
		if (bindresvport(sockfd, (struct sockaddr_in *) &ss) != 0) {
			slapi_log_error(SLAPI_LOG_PLUGIN,
					plugin_description.spd_id,
					"error binding %s socket to a "
					"privileged port: %s\n",
					sock_desc, strerror(errno));
			close(sockfd);
			continue;
		}
		if ((sock_type == SOCK_STREAM) && (listen(sockfd, 128) == -1)) {
			slapi_log_error(SLAPI_LOG_PLUGIN,
					plugin_description.spd_id,
					"error marking %s socket for "
					"listening: %s\n", sock_desc,
					strerror(errno));
			close(sockfd);
			continue;
		}
		if (i == 0) {
			state->resvport = sockfd;
		}
		state->listenfd[state->n_listeners] = sockfd;
		state->listenport[state->n_listeners] = ntohs(*port);
		state->sock_pf[state->n_listeners] = sock_pf;
		state->sock_type[state->n_listeners] = sock_type;
		slapi_log_error(SLAPI_LOG_PLUGIN,
				plugin_description.spd_id,
				"listening on port %d for %s%s clients\n",
				state->listenport[state->n_listeners],
				sock_type == SOCK_STREAM ? "tcp" : "udp",
				sock_pf == PF_INET6 ? "6" : "");
		state->n_listeners++;
	}
	slapi_log_error(SLAPI_LOG_PLUGIN,
			plugin_description.spd_id,
			"set up %d listening sockets\n", state->n_listeners);
	*lstate = state;
	return 0;
failed:
	err = errno;
	if (arena != NULL) {
		PORT_FreeArena(arena, PR_TRUE);
	}
	errno = err;
	return -1;
}

int
nis_plugin_init(Slapi_PBlock *pb)
{
	struct plugin_state *state = NULL;
	if (setup_listener_sockets(&state) == -1) {
		slapi_log_error(SLAPI_LOG_PLUGIN, plugin_description.spd_id,
				"error setting up listening sockets\n");
		return -1;
	}
	slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION, SLAPI_PLUGIN_VERSION_03);
	slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION, &plugin_description);
	slapi_pblock_set(pb, SLAPI_PLUGIN_START_FN, &plugin_start);
	slapi_pblock_set(pb, SLAPI_PLUGIN_CLOSE_FN, &plugin_close);
	slapi_pblock_get(pb, SLAPI_PLUGIN_IDENTITY, &state->plugin_identity);
	state->plugin_desc = &plugin_description;
	slapi_pblock_set(pb, SLAPI_PLUGIN_PRIVATE, state);
	slapi_log_error(SLAPI_LOG_PLUGIN, state->plugin_desc->spd_id,
			"registered plugin hooks\n");
	return 0;
}