/
unixsock.c
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/
unixsock.c
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/**
* collectd - src/unixsock.c
* Copyright (C) 2007,2008 Florian octo Forster
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors:
* Florian octo Forster <octo at collectd.org>
**/
#include "collectd.h"
#include "plugin.h"
#include "utils/common/common.h"
#include "utils/cmds/flush.h"
#include "utils/cmds/getthreshold.h"
#include "utils/cmds/getval.h"
#include "utils/cmds/listval.h"
#include "utils/cmds/putnotif.h"
#include "utils/cmds/putval.h"
#include <sys/stat.h>
#include <sys/un.h>
#include <grp.h>
#ifndef UNIX_PATH_MAX
#define UNIX_PATH_MAX sizeof(((struct sockaddr_un *)0)->sun_path)
#endif
#define US_DEFAULT_PATH LOCALSTATEDIR "/run/" PACKAGE_NAME "-unixsock"
/*
* Private variables
*/
/* valid configuration file keys */
static const char *config_keys[] = {"SocketFile", "SocketGroup", "SocketPerms",
"DeleteSocket"};
static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
static int loop;
/* socket configuration */
static int sock_fd = -1;
static char *sock_file;
static char *sock_group;
static int sock_perms = S_IRWXU | S_IRWXG;
static bool delete_socket;
static pthread_t listen_thread = (pthread_t)0;
/*
* Functions
*/
static int us_open_socket(void) {
struct sockaddr_un sa = {0};
int status;
sock_fd = socket(PF_UNIX, SOCK_STREAM, 0);
if (sock_fd < 0) {
ERROR("unixsock plugin: socket failed: %s", STRERRNO);
return -1;
}
sa.sun_family = AF_UNIX;
sstrncpy(sa.sun_path, (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
sizeof(sa.sun_path));
DEBUG("unixsock plugin: socket path = %s", sa.sun_path);
if (delete_socket) {
errno = 0;
status = unlink(sa.sun_path);
if ((status != 0) && (errno != ENOENT)) {
WARNING("unixsock plugin: Deleting socket file \"%s\" failed: %s",
sa.sun_path, STRERRNO);
} else if (status == 0) {
INFO("unixsock plugin: Successfully deleted socket file \"%s\".",
sa.sun_path);
}
}
status = bind(sock_fd, (struct sockaddr *)&sa, sizeof(sa));
if (status != 0) {
ERROR("unixsock plugin: bind failed: %s", STRERRNO);
close(sock_fd);
sock_fd = -1;
return -1;
}
status = chmod(sa.sun_path, sock_perms);
if (status == -1) {
ERROR("unixsock plugin: chmod failed: %s", STRERRNO);
close(sock_fd);
sock_fd = -1;
return -1;
}
status = listen(sock_fd, 8);
if (status != 0) {
ERROR("unixsock plugin: listen failed: %s", STRERRNO);
close(sock_fd);
sock_fd = -1;
return -1;
}
do {
const char *grpname;
struct group *g;
struct group sg;
long int grbuf_size = sysconf(_SC_GETGR_R_SIZE_MAX);
if (grbuf_size <= 0)
grbuf_size = sysconf(_SC_PAGESIZE);
if (grbuf_size <= 0)
grbuf_size = 4096;
char grbuf[grbuf_size];
grpname = (sock_group != NULL) ? sock_group : COLLECTD_GRP_NAME;
g = NULL;
status = getgrnam_r(grpname, &sg, grbuf, sizeof(grbuf), &g);
if (status != 0) {
WARNING("unixsock plugin: getgrnam_r (%s) failed: %s", grpname,
STRERROR(status));
break;
}
if (g == NULL) {
WARNING("unixsock plugin: No such group: `%s'", grpname);
break;
}
if (chown((sock_file != NULL) ? sock_file : US_DEFAULT_PATH, (uid_t)-1,
g->gr_gid) != 0) {
WARNING("unixsock plugin: chown (%s, -1, %i) failed: %s",
(sock_file != NULL) ? sock_file : US_DEFAULT_PATH, (int)g->gr_gid,
STRERRNO);
}
} while (0);
return 0;
} /* int us_open_socket */
static void *us_handle_client(void *arg) {
int fdin;
int fdout;
FILE *fhin, *fhout;
fdin = *((int *)arg);
free(arg);
arg = NULL;
DEBUG("unixsock plugin: us_handle_client: Reading from fd #%i", fdin);
fdout = dup(fdin);
if (fdout < 0) {
ERROR("unixsock plugin: dup failed: %s", STRERRNO);
close(fdin);
pthread_exit((void *)1);
}
fhin = fdopen(fdin, "r");
if (fhin == NULL) {
ERROR("unixsock plugin: fdopen failed: %s", STRERRNO);
close(fdin);
close(fdout);
pthread_exit((void *)1);
return (void *)1;
}
fhout = fdopen(fdout, "w");
if (fhout == NULL) {
ERROR("unixsock plugin: fdopen failed: %s", STRERRNO);
fclose(fhin); /* this closes fdin as well */
close(fdout);
pthread_exit((void *)1);
return (void *)1;
}
/* change output buffer to line buffered mode */
if (setvbuf(fhout, NULL, _IOLBF, 0) != 0) {
ERROR("unixsock plugin: setvbuf failed: %s", STRERRNO);
fclose(fhin);
fclose(fhout);
pthread_exit((void *)1);
return (void *)0;
}
while (42) {
char buffer[1024];
char buffer_copy[1024];
char *fields[128];
int fields_num;
errno = 0;
if (fgets(buffer, sizeof(buffer), fhin) == NULL) {
if ((errno == EINTR) || (errno == EAGAIN))
continue;
if (errno != 0) {
WARNING("unixsock plugin: failed to read from socket #%i: %s",
fileno(fhin), STRERRNO);
}
break;
}
size_t len = strlen(buffer);
while ((len > 0) &&
((buffer[len - 1] == '\n') || (buffer[len - 1] == '\r')))
buffer[--len] = '\0';
if (len == 0)
continue;
sstrncpy(buffer_copy, buffer, sizeof(buffer_copy));
fields_num =
strsplit(buffer_copy, fields, sizeof(fields) / sizeof(fields[0]));
if (fields_num < 1) {
fprintf(fhout, "-1 Internal error\n");
fclose(fhin);
fclose(fhout);
pthread_exit((void *)1);
return (void *)1;
}
if (strcasecmp(fields[0], "getval") == 0) {
cmd_handle_getval(fhout, buffer);
} else if (strcasecmp(fields[0], "getthreshold") == 0) {
handle_getthreshold(fhout, buffer);
} else if (strcasecmp(fields[0], "putval") == 0) {
cmd_handle_putval(fhout, buffer);
} else if (strcasecmp(fields[0], "listval") == 0) {
cmd_handle_listval(fhout, buffer);
} else if (strcasecmp(fields[0], "putnotif") == 0) {
handle_putnotif(fhout, buffer);
} else if (strcasecmp(fields[0], "flush") == 0) {
cmd_handle_flush(fhout, buffer);
} else {
if (fprintf(fhout, "-1 Unknown command: %s\n", fields[0]) < 0) {
WARNING("unixsock plugin: failed to write to socket #%i: %s",
fileno(fhout), STRERRNO);
break;
}
}
} /* while (fgets) */
DEBUG("unixsock plugin: us_handle_client: Exiting..");
fclose(fhin);
fclose(fhout);
pthread_exit((void *)0);
return (void *)0;
} /* void *us_handle_client */
static void *us_server_thread(void __attribute__((unused)) * arg) {
int status;
int *remote_fd;
pthread_t th;
if (us_open_socket() != 0)
pthread_exit((void *)1);
while (loop != 0) {
DEBUG("unixsock plugin: Calling accept..");
status = accept(sock_fd, NULL, NULL);
if (status < 0) {
if (errno == EINTR)
continue;
ERROR("unixsock plugin: accept failed: %s", STRERRNO);
close(sock_fd);
sock_fd = -1;
pthread_exit((void *)1);
}
remote_fd = malloc(sizeof(*remote_fd));
if (remote_fd == NULL) {
WARNING("unixsock plugin: malloc failed: %s", STRERRNO);
close(status);
continue;
}
*remote_fd = status;
DEBUG("Spawning child to handle connection on fd #%i", *remote_fd);
status = plugin_thread_create(&th, us_handle_client, (void *)remote_fd,
"unixsock conn");
if (status == 0) {
pthread_detach(th);
} else {
WARNING("unixsock plugin: pthread_create failed: %s", STRERRNO);
close(*remote_fd);
free(remote_fd);
continue;
}
} /* while (loop) */
close(sock_fd);
sock_fd = -1;
status = unlink((sock_file != NULL) ? sock_file : US_DEFAULT_PATH);
if (status != 0) {
NOTICE("unixsock plugin: unlink (%s) failed: %s",
(sock_file != NULL) ? sock_file : US_DEFAULT_PATH, STRERRNO);
}
return (void *)0;
} /* void *us_server_thread */
static int us_config(const char *key, const char *val) {
if (strcasecmp(key, "SocketFile") == 0) {
char *new_sock_file = strdup(val);
if (new_sock_file == NULL)
return 1;
sfree(sock_file);
sock_file = new_sock_file;
} else if (strcasecmp(key, "SocketGroup") == 0) {
char *new_sock_group = strdup(val);
if (new_sock_group == NULL)
return 1;
sfree(sock_group);
sock_group = new_sock_group;
} else if (strcasecmp(key, "SocketPerms") == 0) {
sock_perms = (int)strtol(val, NULL, 8);
} else if (strcasecmp(key, "DeleteSocket") == 0) {
if (IS_TRUE(val))
delete_socket = true;
else
delete_socket = false;
} else {
return -1;
}
return 0;
} /* int us_config */
static int us_init(void) {
static int have_init;
int status;
/* Initialize only once. */
if (have_init != 0)
return 0;
have_init = 1;
loop = 1;
status = plugin_thread_create(&listen_thread, us_server_thread, NULL,
"unixsock listen");
if (status != 0) {
ERROR("unixsock plugin: pthread_create failed: %s", STRERRNO);
return -1;
}
return 0;
} /* int us_init */
static int us_shutdown(void) {
void *ret;
loop = 0;
if (listen_thread != (pthread_t)0) {
pthread_kill(listen_thread, SIGTERM);
pthread_join(listen_thread, &ret);
listen_thread = (pthread_t)0;
}
plugin_unregister_init("unixsock");
plugin_unregister_shutdown("unixsock");
return 0;
} /* int us_shutdown */
void module_register(void) {
plugin_register_config("unixsock", us_config, config_keys, config_keys_num);
plugin_register_init("unixsock", us_init);
plugin_register_shutdown("unixsock", us_shutdown);
} /* void module_register (void) */