main.c

系统任务管理器

/* GKrellM
|  Copyright (C) 1999-2006 Bill Wilson
|
|  Author:  Bill Wilson    [e-mail]
|  Latest versions might be found at:  http://gkrellm.net
|
|  This program is free software which I release under the GNU General Public
|  License. You may redistribute and/or modify this program under the terms
|  of that license as published by the Free Software Foundation; either
|  version 2 of the License, or (at your option) any later version.
|
|  This program is distributed in the hope that it will be useful,
|  but WITHOUT ANY WARRANTY; without even the implied warranty of
|  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
|  GNU General Public License for more details.  Version 2 is in the
|  COPYRIGHT file in the top level directory of this distribution.
| 
|  To get a copy of the GNU General Puplic License, write to the Free Software
|  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "gkrellmd.h"
#include "gkrellmd-private.h"

#include "../src/inet.h"

#ifndef HAVE_GETADDRINFO
struct addrinfo
	{
	int		ai_flags;		/* AI_PASSIVE, AI_CANONNAME, AI_NUMERICHOST */
	int		ai_family;		/* PF_xxx */
	int		ai_socktype;	/* SOCK_xxx */
	int		ai_protocol;	/* 0 or IPPROTO_xxx for IPv4 and IPv6 */
	size_t	ai_addrlen;		/* length of ai_addr */
	char	*ai_canonname;	/* canonical name for hostname */
	struct	sockaddr *ai_addr;	/* binary address */
	struct	addrinfo *ai_next;	/* next structure in linked list */
	};
#endif

#if !defined(IPV6_V6ONLY) && defined(IPV6_BINDV6ONLY)
#define	IPV6_V6ONLY	IPV6_BINDV6ONLY
#endif

struct GkrellmdConfig	_GK;
GkrellmdTicks			GK;

GList			*gkrellmd_client_list,
				*gkrellmd_plugin_config_list;

static GList	*allow_host_list;

static gboolean	detach_flag;

#if !defined(WIN32)
struct
	{
	uid_t	uid;
	uid_t	gid;
	}
	drop_privs = { 0, 0 };
#endif

static void
make_pidfile(void)
	{
#if !defined(WIN32)
	FILE	*f;

	if (!_GK.pidfile)
		return;
	f = fopen(_GK.pidfile, "w");
	if (f)
		{
		fprintf(f, "%d\n", getpid());
		fclose(f);
		}
	else
		fprintf(stderr, "gkrellmd: Can't create pidfile %s\n", _GK.pidfile);
#endif
	}

static void
remove_pidfile(void)
	{
#if !defined(WIN32)
	if (_GK.pidfile)
		unlink(_GK.pidfile);
#endif
	}

static void
cb_sigterm(gint sig)
	{
	remove_pidfile();
    exit(0);
	}

gint
gkrellmd_send_to_client(GkrellmdClient *client, gchar *buf)
	{
	gint	n;

	if (!client->alive)
		return 0;
#if defined(MSG_NOSIGNAL)
	n = send(client->fd, buf, strlen(buf), MSG_NOSIGNAL);
#else
	n = send(client->fd, buf, strlen(buf), 0);
#endif
	if (n < 0 && errno == EPIPE)
		{
		if (_GK.verbose)
			printf("Write on closed pipe to host %s\n", client->hostname);
		client->alive = FALSE;
		}
	return n;
	}

#if 0
static gint
getline(gint fd, gchar *buf, gint len)
	{
	fd_set			read_fds;
	struct timeval	tv;
	gchar			*s;
	gint			result, n;

	FD_ZERO(&read_fds);
	FD_SET(fd, &read_fds);
	tv.tv_usec = 0;
	tv.tv_sec = 15;
	s = buf;
	*s = '\0';
	for (n = 0; n < len - 1; ++n)
		{
		result = select(fd + 1, &read_fds, NULL, NULL, &tv);
		if (result <= 0 || read(fd, s, 1) != 1)
			break;
		if (*s == '\n')
			{
			*s = '\0';
			break;
			}
		*++s = '\0';
		}
	return n;
	}
#endif

#ifdef HAVE_GETADDRINFO
static gboolean
is_valid_reverse(char *addr, char *host, sa_family_t family)
	{
	struct addrinfo	hints, *res, *r;
	int		error, good;
	char		addrbuf[NI_MAXHOST];

	/* Reject numeric addresses */
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = family;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
	if (getaddrinfo(host, NULL, &hints, &res) == 0)
		{
		freeaddrinfo(res);
		return 0;
		}

	/* Check for spoof */
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = family;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = AI_PASSIVE;
	if (getaddrinfo(host, NULL, &hints, &res) != 0)
		return 0;
	good = 0;
	for (r = res; good == 0 && r; r = r->ai_next)
		{
		error = getnameinfo(r->ai_addr, r->ai_addrlen,
				    addrbuf, sizeof(addrbuf), NULL, 0,
				    NI_NUMERICHOST | NI_WITHSCOPEID);
		if (error == 0 && strcmp(addr, addrbuf) == 0)
			{
			good = 1;
			break;
			}
		}
	freeaddrinfo(res);
	return good;
	}
#endif

/* Check for CIDR match.
 */
static gboolean
cidr_match(struct sockaddr *sa, socklen_t salen, char *allowed)
{
#ifdef HAVE_GETADDRINFO
	struct addrinfo hints, *res;
	struct sockaddr_storage	ss;
	char		*buf;
	char		*p, *ep;
	guchar		*addr, *pat;
	u_int32_t	mask;
	int			plen, i;
	gboolean	result;

	buf = g_strdup(allowed);
	plen = -1;
	if ((p = strchr(buf, '/')) != NULL)
		{
		plen = strtoul(p + 1, &ep, 10);
		if (errno != 0 || ep == NULL || *ep != '\0' || plen < 0)
			{
			g_free(buf);
			return FALSE;
			}
		*p = '\0';
		allowed = buf;
		}

	memset(&hints, 0, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
	result = getaddrinfo(allowed, NULL, &hints, &res);
	g_free(buf);
	if (result != 0)
		return FALSE;
	memcpy(&ss, res->ai_addr, res->ai_addrlen);
	freeaddrinfo(res);

	if (sa->sa_family != ((struct sockaddr *)&ss)->sa_family)
		return FALSE;
	switch (sa->sa_family)
		{
#if defined(INET6)
		case AF_INET6:
			if (plen < 0)
				plen = 128;
			if (plen > 128)
				return FALSE;
			if (((struct sockaddr_in6 *)&ss)->sin6_scope_id != 0 &&
			    ((struct sockaddr_in6 *)&ss)->sin6_scope_id !=
			    ((struct sockaddr_in6 *)sa)->sin6_scope_id)
				return FALSE;
			addr = (guchar *)&((struct sockaddr_in6 *)sa)->sin6_addr;
			pat = (guchar *)&((struct sockaddr_in6 *)&ss)->sin6_addr;
			i = 0;
			while (plen > 0)
				{
				if (plen < 32)
					{
					mask = htonl(~(0xffffffff >> plen));
					if ((*(u_int32_t *)&addr[i] & mask) !=
					    (*(u_int32_t *)&pat[i] & mask))
						return FALSE;
					break;
					}
				if (*(u_int32_t *)&addr[i] !=
				    *(u_int32_t *)&pat[i])
					return FALSE;
				i += 4;
				plen -= 32;
				}
			break;
#endif
		case AF_INET:
			if (plen < 0)
				plen = 32;
			if (plen > 32)
				return FALSE;
			addr = (guchar *)&((struct sockaddr_in *)sa)->sin_addr;
			pat = (guchar *)&((struct sockaddr_in *)&ss)->sin_addr;
			mask = htonl(~(0xffffffff >> plen));
			if ((*(u_int32_t *)addr & mask) !=
			    (*(u_int32_t *)pat & mask))
				return FALSE;
			break;
		default:
			return FALSE;
		}
	return TRUE;
#else
	return FALSE;
#endif
}

static gboolean
allow_host(GkrellmdClient *client, struct sockaddr *sa, socklen_t salen)
	{
	GList			*list;
#ifdef HAVE_GETADDRINFO
	int error;
	char hostbuf[NI_MAXHOST], addrbuf[NI_MAXHOST];
#else
	struct hostent	*hostent;
#endif
	gchar			buf[128];
	gchar			*hostname = NULL,
					*addr = NULL;
	gchar			*s, *allowed;

#ifdef HAVE_GETADDRINFO
	error = getnameinfo(sa, salen, addrbuf, sizeof(addrbuf),
			    NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID);
	if (error == 0)
		{
		addr = addrbuf;
		error = getnameinfo(sa, salen, hostbuf, sizeof(hostbuf),
				    NULL, 0, NI_NAMEREQD);
		if (error == 0 &&
		    is_valid_reverse(addrbuf, hostbuf, sa->sa_family))
			hostname = hostbuf;
		}
#else
	hostent = gethostbyaddr((gchar *)&((struct sockaddr_in *)sa)->sin_addr,
				sizeof(struct in_addr), AF_INET);
	if (hostent)
		hostname = hostent->h_name;
	addr = inet_ntoa(((struct sockaddr_in *)sa)->sin_addr);
#endif

	client->hostname = g_strdup(hostname ? hostname : addr);

	if (!allow_host_list)
		return TRUE;

	for (list = allow_host_list; list; list = list->next)
		{
		allowed = (gchar *) list->data;
		if (   (hostname && !strcmp(hostname, allowed))
			|| (addr && !strcmp(addr, allowed))
			|| !strcmp("ALL", allowed)
		   )
			return TRUE;

		if (addr && cidr_match(sa, salen, allowed))
			return TRUE;

		/* Check for simple IPv4 subnet match.  Worry later about ranges and
		|  other hosts_access type patterns.
		*/
		if (   addr
			&& (s = strrchr(allowed, (int) '.')) != NULL
			&& *(s + 1) == '*' && *(s + 2) == '\0'
			&& !strncmp(addr, allowed, (gint) (s - allowed + 1))
		   )
				return TRUE;
		}

	snprintf(buf, sizeof(buf), _("Connection not allowed from %s\n"),
			hostname ? hostname : addr);
	fprintf(stderr, "gkrellmd: %s", buf),
	gkrellmd_send_to_client(client, "<error>\n");
	gkrellmd_send_to_client(client, buf);
	return FALSE;
	}

  /* client sends line: gkrellm x.y.z
  */
static GkrellmdClient *
accept_client(gint fd, struct sockaddr *sa, socklen_t salen)
	{
	GkrellmdClient	*client;
	gchar			buf[64], name[32];
	gboolean		client_limit;
	gint			err;

	client = g_new0(GkrellmdClient, 1);
	client->fd = fd;
	client->alive = TRUE;
	client_limit = (g_list_length(gkrellmd_client_list) >= _GK.max_clients);

	if (!allow_host(client, sa, salen) || client_limit)
		{
		if (client_limit)
			{
			fprintf(stderr, _("gkrellmd: too many clients, rejecting %s\n"),
					client->hostname);
			gkrellmd_send_to_client(client,
						"<error>\nClient limit exceeded.\n");
			}
		g_free(client->hostname);
		g_free(client);
		return NULL;
		}
	err = recv(fd, buf, sizeof(buf), 0);
	if (err > 0)
		buf[err] = '\0';
	else
		buf[0] = '\0';
	//getline(fd, buf, sizeof(buf));

	if (_GK.verbose)
		printf(_("connect string from client: %s\n"), buf);

	if (   sscanf(buf, "%31s %d.%d.%d", name, &client->major_version,
					&client->minor_version, &client->rev_version) == 4
		&& !strcmp(name, "gkrellm")
	   )
		{
		gkrellmd_client_list = g_list_append(gkrellmd_client_list, client);
		return client;
		}
	fprintf(stderr, _("gkrellmd: bad connect line from %s: %s\n"),
				client->hostname, buf);
	gkrellmd_send_to_client(client, "<error>\nBad connect string!");

	g_free(client->hostname);
	g_free(client);
	return NULL;
	}

static void
remove_client(gint fd)
	{
	GList			*list;
	GkrellmdClient	*client;

	for (list = gkrellmd_client_list; list; list = list->next)
		{
		client = (GkrellmdClient *) list->data;
		if (client->fd == fd)
			{
			if (_GK.verbose)
				printf("Removing client %s\n", client->hostname);
			close(fd);
			g_free(client->hostname);
			g_free(client);
			gkrellmd_client_list = g_list_remove(gkrellmd_client_list, client);
			break;
			}
		}
	}

static gint
parse_config(gchar *config, gchar *arg)
	{
	if (!strcmp(config, "clear-hosts") || !strcmp(config, "c"))
		{
		gkrellm_free_glist_and_data(&allow_host_list);
		return 0;
		}
	if (!strcmp(config, "detach") || !strcmp(config, "d"))
		{
		detach_flag = TRUE;
		return 0;
		}
	if (!arg || !*arg)
		return -1;
	if (!strcmp(config, "update-hz") || !strcmp(config, "u"))
		_GK.update_HZ = atoi(arg);
	else if (!strcmp(config, "port") || !strcmp(config, "P"))
		_GK.server_port = atoi(arg);
	else if (!strcmp(config, "max-clients") || !strcmp(config, "m"))
		_GK.max_clients = atoi(arg);
	else if (!strcmp(config, "allow-host") || !strcmp(config, "a"))
		allow_host_list = g_list_append(allow_host_list, g_strdup(arg));
	else if (!strcmp(config, "plugin-enable") || !strcmp(config, "pe"))
		gkrellmd_plugin_enable_list
				= g_list_append(gkrellmd_plugin_enable_list, g_strdup(arg));
	else if (!strcmp(config, "plugin") || !strcmp(config, "p"))
		_GK.command_line_plugin = g_strdup(arg);
	else if (!strcmp(config, "io-timeout"))
		_GK.io_timeout = atoi(arg);
	else if (!strcmp(config, "reconnect-timeout"))
		_GK.reconnect_timeout = atoi(arg);
	else if (!strcmp(config, "fs-interval"))
		_GK.fs_interval = atoi(arg);
	else if (!strcmp(config, "nfs-interval"))
		_GK.nfs_interval = atoi(arg);
	else if (!strcmp(config, "inet-interval"))
		_GK.inet_interval = atoi(arg);
	else if (!strcmp(config, "mbmon-port"))
		_GK.mbmon_port = atoi(arg);
	else if (!strcmp(config, "net-timer"))
		_GK.net_timer = g_strdup(arg);
	else if (!strcmp(config, "debug-level") || !strcmp(config, "debug"))
		_GK.debug_level = (gint) strtoul(arg, NULL, 0);
#if !defined(WIN32)
	else if (!strcmp(config, "pidfile"))
		_GK.pidfile = g_strdup(arg);
	else if (!strcmp(config, "mailbox"))
		gkrellmd_add_mailbox(arg);
	else if (!strcmp(config, "user") || !strcmp(config, "U"))
		{
		struct passwd *tmp;

		if ((tmp = getpwnam(arg)) != (struct passwd*) 0)
			drop_privs.uid = tmp->pw_uid;
		else
			return -1;
		}
	else if (!strcmp(config, "group") || !strcmp(config, "G"))
		{
		struct group *tmp;

		if ((tmp = getgrnam(arg)) != (struct group*) 0)
			drop_privs.gid = tmp->gr_gid;
		else
			return -1;
		}
#endif
	else
		return -1;
	return 1;
	}

static void
load_config(gchar *path)
	{
	FILE			*f;
	PluginConfigRec	*cfg;
	gchar			buf[128], config[32], arg[128];
	gchar			*s, *plugin_config_block = NULL;

	f = fopen(path, "r");
	if (!f)
		return;
	while (fgets(buf, sizeof(buf), f))
		{
		if (!buf[0] || buf[0] == '#')
			continue;
		if (buf[0] == '[' || buf[0] == '<')
			{
			if (buf[1] == '/')
				{
				g_free(plugin_config_block);
				plugin_config_block = NULL;
				}
			else
				{
				if (   (s = strchr(buf, ']')) != NULL
					|| (s = strchr(buf, '>')) != NULL
				   )
					*s = '\0';
				plugin_config_block = g_strdup(&buf[1]);
				}
			continue;
			}
		if (plugin_config_block)
			{
			cfg = g_new0(PluginConfigRec, 1);
			cfg->name = g_strdup(plugin_config_block);
			if ((s = strchr(buf, '\n')) != NULL)
				*s = '\0';
			cfg->line = g_strdup(buf);
			gkrellmd_plugin_config_list
						= g_list_append(gkrellmd_plugin_config_list, cfg);
			}
		else	/* main gkrellmd config line */