diff options
Diffstat (limited to 'xorg-server/os/client.c')
| -rw-r--r-- | xorg-server/os/client.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/xorg-server/os/client.c b/xorg-server/os/client.c new file mode 100644 index 000000000..1311855d5 --- /dev/null +++ b/xorg-server/os/client.c @@ -0,0 +1,310 @@ +/* + * 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" + +/** + * 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 cmdsize = 0; + int argsize = 0; + int fd = 0; + + if (cmdname) + *cmdname = NULL; + if (cmdargs) + *cmdargs = NULL; + + if (pid == -1) + return; + + /* 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) + return; + + /* Read the contents of /proc/pid/cmdline. It should contain the + * process name and arguments. */ + totsize = read(fd, path, sizeof(path)); + if (totsize <= 0) + return; + if (close(fd) < 0) + return; + path[totsize - 1] = '\0'; + + /* Contruct the process name without arguments. */ + cmdsize = strlen(path) + 1; + if (cmdname) + { + char *name = malloc(cmdsize); + if (name) + { + strncpy(name, path, cmdsize); + name[cmdsize - 1] = '\0'; + *cmdname = name; + } + } + + /* Construct the arguments for client process. */ + argsize = totsize - cmdsize; + if (cmdargs && (argsize > 0)) + { + char *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; + } + } +} + +/** + * 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", + client->clientAsMask, client->clientIds->pid); + DebugF("client(%lx): Reserved cmdname(%s) and cmdargs(%s).\n", + 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", + client->clientAsMask, client->clientIds->pid); + DebugF("client(%lx): Released cmdline(%s) and cmdargs(%s).\n", + 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; +} |