Edit
IABSD.fr/xenocara/xserver/os/client.c
matthieu
- xserver/os/client.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 #ifdef __APPLE__ #include <dispatch/dispatch.h> #include <errno.h> #include <sys/sysctl.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) { #if !defined(__APPLE__) && !defined(__OpenBSD__) char path[PATH_MAX + 1]; int totsize = 0; int fd = 0; #endif if (cmdname) *cmdname = NULL; if (cmdargs) *cmdargs = NULL; if (pid == -1) return; #if defined (__APPLE__) { static dispatch_once_t once; static int argmax; dispatch_once(&once, ^{ int mib[2]; size_t len; mib[0] = CTL_KERN; mib[1] = KERN_ARGMAX; len = sizeof(argmax); if (sysctl(mib, 2, &argmax, &len, NULL, 0) == -1) { ErrorF("Unable to dynamically determine kern.argmax, using ARG_MAX (%d)\n", ARG_MAX); argmax = ARG_MAX; } }); int mib[3]; size_t len = argmax; int32_t argc = -1; char * const procargs = malloc(len); if (!procargs) { ErrorF("Failed to allocate memory (%lu bytes) for KERN_PROCARGS2 result for pid %d: %s\n", len, pid, strerror(errno)); return; } mib[0] = CTL_KERN; mib[1] = KERN_PROCARGS2; mib[2] = pid; if (sysctl(mib, 3, procargs, &len, NULL, 0) == -1) { ErrorF("Failed to determine KERN_PROCARGS2 for pid %d: %s\n", pid, strerror(errno)); free(procargs); return; } if (len < sizeof(argc) || len > argmax) { ErrorF("Erroneous length returned when querying KERN_PROCARGS2 for pid %d: %zu\n", pid, len); free(procargs); return; } /* Ensure we have a failsafe NUL termination just in case the last entry * was not actually NUL terminated. */ procargs[len-1] = '\0'; /* Setup our iterator */ char *is = procargs; /* The first element in the buffer is argc as a 32bit int. When using * the older KERN_PROCARGS, this is omitted, and one needs to guess * (usually by checking for an `=` character) when we start seeing * envvars instead of arguments. */ argc = *(int32_t *)is; is += sizeof(argc); /* The very next string is the executable path. Skip over it since * this function wants to return argv[0] and argv[1...n]. */ is += strlen(is) + 1; /* Skip over extra NUL characters to get to the start of argv[0] */ for (; (is < &procargs[len]) && !(*is); is++); if (! (is < &procargs[len])) { ErrorF("Arguments were not returned when querying KERN_PROCARGS2 for pid %d: %zu\n", pid, len); free(procargs); return; } if (cmdname) { *cmdname = strdup(is); } /* Jump over argv[0] and point to argv[1] */ is += strlen(is) + 1; if (cmdargs && is < &procargs[len]) { char *args = is; /* Remove the NUL terminators except the last one */ for (int i = 1; i < argc - 1; i++) { /* Advance to the NUL terminator */ is += strlen(is); /* Change the NUL to a space, ensuring we don't accidentally remove the terminal NUL */ if (is < &procargs[len-1]) { *is = ' '; } } *cmdargs = strdup(args); } free(procargs); } #elif 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); if (cmdname) { if (argv == NULL || argv[0] == NULL) return; else *cmdname = strdup(argv[0]); } if (cmdargs) { i = 1; while (argv[i] != NULL) { len += strlen(argv[i]) + 1; i++; } *cmdargs = calloc(1, len); i = 1; while (argv[i] != NULL) { strlcat(*(char **)cmdargs, argv[i], len); strlcat(*(char **)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'; /* Construct 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; }