Differential D4277 Diff 10503 lib/libcasper/libcasper/libcasper_service.c

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lib/libcasper/libcasper/libcasper_service.c

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				/*-
				* Copyright (c) 2012 The FreeBSD Foundation
				* Copyright (c) 2015 Mariusz Zaborski <oshogbo@FreeBSD.org>
				* All rights reserved.
				*
				* This software was developed by Pawel Jakub Dawidek under sponsorship from
				* the FreeBSD Foundation.
				*
				* Redistribution and use in source and binary forms, with or without
				* modification, are permitted provided that the following conditions
				* are met:
				* 1. Redistributions of source code must retain the above copyright
				* notice, this list of conditions and the following disclaimer.
				* 2. Redistributions in binary form must reproduce the above copyright
				* notice, this list of conditions and the following disclaimer in the
				* documentation and/or other materials provided with the distribution.
				*
				* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
				* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
				* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
				* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
				* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
				* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
				* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
				* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
				* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
				* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
				* SUCH DAMAGE.
				*/

				#include <sys/cdefs.h>
				__FBSDID("$FreeBSD$");

				#include <sys/types.h>
				#include <sys/queue.h>
				#include <sys/socket.h>
				#include <sys/nv.h>

				#include <assert.h>
				#include <errno.h>
				#include <stdbool.h>
				#include <stdio.h>
				#include <stdlib.h>
				#include <string.h>
				#include <unistd.h>

				#include "libcasper_impl.h"
				#include "zygote.h"

				struct casper_service {
				struct service *cs_service;
				TAILQ_ENTRY(casper_service) cs_next;
				};

				static TAILQ_HEAD(, casper_service) casper_services =
				TAILQ_HEAD_INITIALIZER(casper_services);

				#define CORE_CASPER_NAME "core.casper"
				#define CSERVICE_IS_CORE(service) \
				(strcmp(service_name(service->cs_service), CORE_CASPER_NAME) == 0)

				static struct casper_service *
				service_find(const char *name)
				{
				struct casper_service *casserv;

				TAILQ_FOREACH(casserv, &casper_services, cs_next) {
				if (strcmp(service_name(casserv->cs_service), name) == 0)
				break;
				}
				return (casserv);
				}

				struct casper_service *
				service_register(const char name, service_limit_func_t limitfunc,
				service_command_func_t *commandfunc)
				{
				struct casper_service *casserv;

				if (commandfunc == NULL)
				return (NULL);
				if (name == NULL \|\| name[0] == '\0')
				return (NULL);
				if (service_find(name) != NULL)
				return (NULL);

				casserv = malloc(sizeof(*casserv));
				if (casserv == NULL)
				return (NULL);

				casserv->cs_service = service_alloc(name, limitfunc, commandfunc);
				if (casserv->cs_service == NULL) {
				free(casserv);
				return (NULL);
				}
				TAILQ_INSERT_TAIL(&casper_services, casserv, cs_next);

				return (casserv);
				}

				static bool
				casper_allowed_service(const nvlist_t limits, const char service)
				{

				if (limits == NULL)
				return (true);

				if (nvlist_exists_null(limits, service))
				return (true);

				return (false);
				}

				static int
				casper_limit(const nvlist_t oldlimits, const nvlist_t newlimits)
				{
				const char *name;
				int type;
				void *cookie;

				cookie = NULL;
				while ((name = nvlist_next(newlimits, &type, &cookie)) != NULL) {
				if (type != NV_TYPE_NULL)
				return (EINVAL);
				if (!casper_allowed_service(oldlimits, name))
				return (ENOTCAPABLE);
				}

				return (0);
				}

				static void
				service_execute(int chanfd)
				{
				struct service *service;
				nvlist_t *nvl;
				int procfd;

				nvl = nvlist_recv(chanfd, 0);
				if (nvl == NULL)
				exit(1);
				service = (struct service *)(uintptr_t)nvlist_take_number(nvl,
				"service");
				//XXX: We should remove this?
				procfd = nvlist_take_descriptor(nvl, "procfd");
				nvlist_destroy(nvl);

				service_start(service, chanfd);
				/* Not reached. */
				exit(1);
				}

				static int
				casper_command(const char cmd, const nvlist_t limits, nvlist_t *nvlin,
				nvlist_t *nvlout)
				{
				struct casper_service *casserv;
				const char *servname;
				nvlist_t *nvl;
				int chanfd, procfd, error;

				if (strcmp(cmd, "open") != 0)
				return (EINVAL);
				if (!nvlist_exists_string(nvlin, "service"))
				return (EINVAL);

				servname = nvlist_get_string(nvlin, "service");
				casserv = service_find(servname);
				if (casserv == NULL)
				return (ENOENT);

				if (!casper_allowed_service(limits, servname))
				return (ENOTCAPABLE);

				if (zygote_clone(service_execute, &chanfd, &procfd) == -1)
				return (errno);

				nvl = nvlist_create(0);
				nvlist_add_number(nvl, "service",
				(uint64_t)(uintptr_t)casserv->cs_service);
				nvlist_move_descriptor(nvl, "procfd", procfd);
				if (nvlist_send(chanfd, nvl) == -1) {
				error = errno;
				nvlist_destroy(nvl);
				close(chanfd);
				return (error);
				}
				nvlist_destroy(nvl);

				nvlist_move_descriptor(nvlout, "chanfd", chanfd);

				return (0);
				}

				static void
				service_register_core(int fd)
				{
				struct casper_service *casserv;
				struct service_connection *sconn;

				casserv = service_register(CORE_CASPER_NAME, casper_limit,
				casper_command);
				sconn = service_connection_add(casserv->cs_service, fd, NULL);
				if (sconn == NULL) {
				close(fd);
				abort();
				}
				}

				void
				casper_main_loop(int fd)
				{
				fd_set fds;
				struct casper_service *casserv;
				struct service_connection sconn, sconntmp;
				int sock, maxfd, ret;

				if (zygote_init() < 0)
				exit(1);

				/*
				* Register core services.
				*/
				service_register_core(fd);

				for (;;) {
				FD_ZERO(&fds);
				FD_SET(fd, &fds);
				maxfd = -1;
				TAILQ_FOREACH(casserv, &casper_services, cs_next) {
				/* We handle only core services. */
				if (!CSERVICE_IS_CORE(casserv))
				continue;
				for (sconn = service_connection_first(casserv->cs_service);
				sconn != NULL;
				sconn = service_connection_next(sconn)) {
				sock = service_connection_get_sock(sconn);
				FD_SET(sock, &fds);
				maxfd = sock > maxfd ? sock : maxfd;
				}
				}
				if (maxfd == -1) {
				/* Nothing to do. */
				exit(0);
				}
				maxfd++;


				assert(maxfd <= (int)FD_SETSIZE);
				ret = select(maxfd, &fds, NULL, NULL, NULL);
				assert(ret == -1 \|\| ret > 0); /* select() cannot timeout */
				if (ret == -1) {
				if (errno == EINTR)
				continue;
				exit(1);
				}

				TAILQ_FOREACH(casserv, &casper_services, cs_next) {
				/* We handle only core services. */
				if (!CSERVICE_IS_CORE(casserv))
				continue;
				for (sconn = service_connection_first(casserv->cs_service);
				sconn != NULL; sconn = sconntmp) {
				/*
				* Prepare for connection to be removed from
				* the list on failure.
				*/
				sconntmp = service_connection_next(sconn);
				sock = service_connection_get_sock(sconn);
				if (FD_ISSET(sock, &fds)) {
				service_message(casserv->cs_service,
				sconn);
				}
				}
				}
				}
				}