xenocara/xserver/os/client.c
2019-07-27 07:57:06 +00:00

406 lines
12 KiB
C

/*
* Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). All
* rights reserved.
* Copyright (c) 1993, 2010, Oracle and/or its affiliates. All rights reserved.
*
* 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.
*/
/**
* @file
*
* This file contains functionality for identifying clients by various
* means. The primary purpose of identification is to simply aid in
* finding out which clients are using X server and how they are using
* it. For example, it's often necessary to monitor what requests
* clients are executing (to spot bad behaviour) and how they are
* allocating resources in X server (to spot excessive resource
* usage).
*
* This framework automatically allocates information, that can be
* used for client identification, when a client connects to the
* server. The information is freed when the client disconnects. The
* allocated information is just a collection of various IDs, such as
* PID and process name for local clients, that are likely to be
* useful in analyzing X server usage.
*
* Users of the framework can query ID information about clients at
* any time. To avoid repeated polling of IDs the users can also
* subscribe for notifications about the availability of ID
* information. IDs have been allocated before ClientStateCallback is
* called with ClientStateInitial state. Similarly the IDs will be
* released after ClientStateCallback is called with ClientStateGone
* state.
*
* Author: Rami Ylimäki <rami.ylimaki@vincit.fi>
*/
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "client.h"
#include "os.h"
#include "dixstruct.h"
#ifdef __sun
#include <errno.h>
#include <procfs.h>
#endif
#ifdef __OpenBSD__
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/types.h>
#include <kvm.h>
#include <limits.h>
#endif
/**
* Try to determine a PID for a client from its connection
* information. This should be called only once when new client has
* connected, use GetClientPid to determine the PID at other times.
*
* @param[in] client Connection linked to some process.
*
* @return PID of the client. Error (-1) if PID can't be determined
* for the client.
*
* @see GetClientPid
*/
pid_t
DetermineClientPid(struct _Client * client)
{
LocalClientCredRec *lcc = NULL;
pid_t pid = -1;
if (client == NullClient)
return pid;
if (client == serverClient)
return getpid();
if (GetLocalClientCreds(client, &lcc) != -1) {
if (lcc->fieldsSet & LCC_PID_SET)
pid = lcc->pid;
FreeLocalClientCreds(lcc);
}
return pid;
}
/**
* Try to determine a command line string for a client based on its
* PID. Note that mapping PID to a command hasn't been implemented for
* some operating systems. This should be called only once when a new
* client has connected, use GetClientCmdName/Args to determine the
* string at other times.
*
* @param[in] pid Process ID of a client.
* @param[out] cmdname Client process name without arguments. You must
* release this by calling free. On error NULL is
* returned. Pass NULL if you aren't interested in
* this value.
* @param[out] cmdargs Arguments to client process. Useful for
* identifying a client that is executed from a
* launcher program. You must release this by
* calling free. On error NULL is returned. Pass
* NULL if you aren't interested in this value.
*
* @see GetClientCmdName/Args
*/
void
DetermineClientCmd(pid_t pid, const char **cmdname, const char **cmdargs)
{
char path[PATH_MAX + 1];
int totsize = 0;
int fd = 0;
if (cmdname)
*cmdname = NULL;
if (cmdargs)
*cmdargs = NULL;
if (pid == -1)
return;
#if defined(__OpenBSD__)
/* on OpenBSD use kvm_getargv() */
{
kvm_t *kd;
char errbuf[_POSIX2_LINE_MAX];
char **argv;
struct kinfo_proc *kp;
size_t len = 0;
int i, n;
kd = kvm_open(NULL, NULL, NULL, KVM_NO_FILES, errbuf);
if (kd == NULL)
return;
kp = kvm_getprocs(kd, KERN_PROC_PID, pid, sizeof(struct kinfo_proc),
&n);
if (n != 1)
return;
argv = kvm_getargv(kd, kp, 0);
*cmdname = strdup(argv[0]);
i = 1;
while (argv[i] != NULL) {
len += strlen(argv[i]) + 1;
i++;
}
*cmdargs = calloc(1, len);
i = 1;
while (argv[i] != NULL) {
strlcat(*cmdargs, argv[i], len);
strlcat(*cmdargs, " ", len);
i++;
}
kvm_close(kd);
}
#else /* Linux using /proc/pid/cmdline */
/* Check if /proc/pid/cmdline exists. It's not supported on all
* operating systems. */
if (snprintf(path, sizeof(path), "/proc/%d/cmdline", pid) < 0)
return;
fd = open(path, O_RDONLY);
if (fd < 0)
#ifdef __sun
goto fallback;
#else
return;
#endif
/* Read the contents of /proc/pid/cmdline. It should contain the
* process name and arguments. */
totsize = read(fd, path, sizeof(path));
close(fd);
if (totsize <= 0)
return;
path[totsize - 1] = '\0';
/* Contruct the process name without arguments. */
if (cmdname) {
*cmdname = strdup(path);
}
/* Construct the arguments for client process. */
if (cmdargs) {
int cmdsize = strlen(path) + 1;
int argsize = totsize - cmdsize;
char *args = NULL;
if (argsize > 0)
args = malloc(argsize);
if (args) {
int i = 0;
for (i = 0; i < (argsize - 1); ++i) {
const char c = path[cmdsize + i];
args[i] = (c == '\0') ? ' ' : c;
}
args[argsize - 1] = '\0';
*cmdargs = args;
}
}
return;
#endif
#ifdef __sun /* Solaris */
fallback:
/* Solaris prior to 11.3.5 does not support /proc/pid/cmdline, but
* makes information similar to what ps shows available in a binary
* structure in the /proc/pid/psinfo file. */
if (snprintf(path, sizeof(path), "/proc/%d/psinfo", pid) < 0)
return;
fd = open(path, O_RDONLY);
if (fd < 0) {
ErrorF("Failed to open %s: %s\n", path, strerror(errno));
return;
}
else {
psinfo_t psinfo = { 0 };
char *sp;
totsize = read(fd, &psinfo, sizeof(psinfo_t));
close(fd);
if (totsize <= 0)
return;
/* pr_psargs is the first PRARGSZ (80) characters of the command
* line string - assume up to the first space is the command name,
* since it's not delimited. While there is also pr_fname, that's
* more limited, giving only the first 16 chars of the basename of
* the file that was exec'ed, thus cutting off many long gnome
* command names, or returning "isapython2.6" for all python scripts.
*/
psinfo.pr_psargs[PRARGSZ - 1] = '\0';
sp = strchr(psinfo.pr_psargs, ' ');
if (sp)
*sp++ = '\0';
if (cmdname)
*cmdname = strdup(psinfo.pr_psargs);
if (cmdargs && sp)
*cmdargs = strdup(sp);
}
#endif
}
/**
* Called when a new client connects. Allocates client ID information.
*
* @param[in] client Recently connected client.
*/
void
ReserveClientIds(struct _Client *client)
{
#ifdef CLIENTIDS
if (client == NullClient)
return;
assert(!client->clientIds);
client->clientIds = calloc(1, sizeof(ClientIdRec));
if (!client->clientIds)
return;
client->clientIds->pid = DetermineClientPid(client);
if (client->clientIds->pid != -1)
DetermineClientCmd(client->clientIds->pid, &client->clientIds->cmdname,
&client->clientIds->cmdargs);
DebugF("client(%lx): Reserved pid(%d).\n",
(unsigned long) client->clientAsMask, client->clientIds->pid);
DebugF("client(%lx): Reserved cmdname(%s) and cmdargs(%s).\n",
(unsigned long) client->clientAsMask,
client->clientIds->cmdname ? client->clientIds->cmdname : "NULL",
client->clientIds->cmdargs ? client->clientIds->cmdargs : "NULL");
#endif /* CLIENTIDS */
}
/**
* Called when an existing client disconnects. Frees client ID
* information.
*
* @param[in] client Recently disconnected client.
*/
void
ReleaseClientIds(struct _Client *client)
{
#ifdef CLIENTIDS
if (client == NullClient)
return;
if (!client->clientIds)
return;
DebugF("client(%lx): Released pid(%d).\n",
(unsigned long) client->clientAsMask, client->clientIds->pid);
DebugF("client(%lx): Released cmdline(%s) and cmdargs(%s).\n",
(unsigned long) client->clientAsMask,
client->clientIds->cmdname ? client->clientIds->cmdname : "NULL",
client->clientIds->cmdargs ? client->clientIds->cmdargs : "NULL");
free((void *) client->clientIds->cmdname); /* const char * */
free((void *) client->clientIds->cmdargs); /* const char * */
free(client->clientIds);
client->clientIds = NULL;
#endif /* CLIENTIDS */
}
/**
* Get cached PID of a client.
*
* param[in] client Client whose PID has been already cached.
*
* @return Cached client PID. Error (-1) if called:
* - before ClientStateInitial client state notification
* - after ClientStateGone client state notification
* - for remote clients
*
* @see DetermineClientPid
*/
pid_t
GetClientPid(struct _Client *client)
{
if (client == NullClient)
return -1;
if (!client->clientIds)
return -1;
return client->clientIds->pid;
}
/**
* Get cached command name string of a client.
*
* param[in] client Client whose command line string has been already
* cached.
*
* @return Cached client command name. Error (NULL) if called:
* - before ClientStateInitial client state notification
* - after ClientStateGone client state notification
* - for remote clients
* - on OS that doesn't support mapping of PID to command line
*
* @see DetermineClientCmd
*/
const char *
GetClientCmdName(struct _Client *client)
{
if (client == NullClient)
return NULL;
if (!client->clientIds)
return NULL;
return client->clientIds->cmdname;
}
/**
* Get cached command arguments string of a client.
*
* param[in] client Client whose command line string has been already
* cached.
*
* @return Cached client command arguments. Error (NULL) if called:
* - before ClientStateInitial client state notification
* - after ClientStateGone client state notification
* - for remote clients
* - on OS that doesn't support mapping of PID to command line
*
* @see DetermineClientCmd
*/
const char *
GetClientCmdArgs(struct _Client *client)
{
if (client == NullClient)
return NULL;
if (!client->clientIds)
return NULL;
return client->clientIds->cmdargs;
}