[PATCH v3 1/2] dix: Add facilities for client ID tracking.
Vignatti Tiago (Nokia-MS/Helsinki)
tiago.vignatti at nokia.com
Tue Oct 19 09:47:07 PDT 2010
On Fri, Oct 01, 2010 at 05:14:44PM +0200, ext Rami Ylimäki wrote:
> An interface is provided for figuring out the PID and process name of
> a client. Make some existing functionality from SELinux and IA
> extensions available for general use.
>
> Signed-off-by: Rami Ylimäki <rami.ylimaki at vincit.fi>
Reviewed-by: Tiago Vignatti <tiago.vignatti at nokia.com>
> ---
> configure.ac | 15 ++-
> dix/Makefile.am | 1 +
> dix/client.c | 345 ++++++++++++++++++++++++++++++++++++++++++
> dix/main.c | 3 +
> hw/xfree86/loader/sdksyms.sh | 1 +
> include/Makefile.am | 1 +
> include/client.h | 60 ++++++++
> include/dix-config.h.in | 3 +
> include/os.h | 3 +
> os/access.c | 76 +++++++++
> 10 files changed, 507 insertions(+), 1 deletions(-)
> create mode 100644 dix/client.c
> create mode 100644 include/client.h
>
> diff --git a/configure.ac b/configure.ac
> index 1a1f2d3..056d68f 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -645,6 +645,7 @@ AC_ARG_ENABLE(vbe, AS_HELP_STRING([--enable-vbe], [Build Xorg with VB
> AC_ARG_ENABLE(int10-module, AS_HELP_STRING([--enable-int10-module], [Build Xorg with int10 module (default: enabled)]), [INT10MODULE=$enableval], [INT10MODULE=yes])
> AC_ARG_ENABLE(windowswm, AS_HELP_STRING([--enable-windowswm], [Build XWin with WindowsWM extension (default: no)]), [WINDOWSWM=$enableval], [WINDOWSWM=no])
> AC_ARG_ENABLE(libdrm, AS_HELP_STRING([--enable-libdrm], [Build Xorg with libdrm support (default: enabled)]), [DRM=$enableval],[DRM=yes])
> +AC_ARG_ENABLE(clientids, AS_HELP_STRING([--disable-clientids], [Build Xorg with client ID tracking (default: enabled)]), [CLIENTIDS=$enableval], [CLIENTIDS=yes])
>
> dnl DDXes.
> AC_ARG_ENABLE(xorg, AS_HELP_STRING([--enable-xorg], [Build Xorg server (default: auto)]), [XORG=$enableval], [XORG=auto])
> @@ -999,6 +1000,18 @@ if test "x$RES" = xyes; then
> REQUIRED_MODULES="$REQUIRED_MODULES $RESOURCEPROTO"
> fi
>
> +# The XRes extension may support client ID tracking only if it has
> +# been specifically enabled. Client ID tracking is implicitly not
> +# supported if XRes extension is disabled.
> +AC_MSG_CHECKING([whether to track client ids])
> +if test "x$RES" = xyes && test "x$CLIENTIDS" = xyes; then
> + AC_DEFINE(CLIENTIDS, 1, [Support client ID tracking])
> +else
> + CLIENTIDS=no
> +fi
> +AC_MSG_RESULT([$CLIENTIDS])
> +AM_CONDITIONAL(CLIENTIDS, [test "x$CLIENTIDS" = xyes])
> +
> if test "x$GLX" = xyes; then
> PKG_CHECK_MODULES([XLIB], [x11])
> PKG_CHECK_MODULES([GL], $GLPROTO $LIBGL)
> @@ -1527,7 +1540,7 @@ if test "x$XNEST" = xyes; then
> if test "x$have_xnest" = xno; then
> AC_MSG_ERROR([Xnest build explicitly requested, but required modules not found.])
> fi
> - XNEST_LIBS="$FB_LIB $FIXES_LIB $MI_LIB $XEXT_LIB $DBE_LIB $RECORD_LIB $GLX_LIBS $RANDR_LIB $RENDER_LIB $DAMAGE_LIB $MIEXT_DAMAGE_LIB $MIEXT_SHADOW_LIB $XI_LIB $XKB_LIB $XKB_STUB_LIB $COMPOSITE_LIB $DIX_LIB $MAIN_LIB $OS_LIB"
> + XNEST_LIBS="$FB_LIB $FIXES_LIB $MI_LIB $XEXT_LIB $DBE_LIB $RECORD_LIB $GLX_LIBS $RANDR_LIB $RENDER_LIB $DAMAGE_LIB $MIEXT_DAMAGE_LIB $MIEXT_SHADOW_LIB $XI_LIB $XKB_LIB $XKB_STUB_LIB $COMPOSITE_LIB $MAIN_LIB $DIX_LIB $OS_LIB"
> XNEST_SYS_LIBS="$XNESTMODULES_LIBS $GLX_SYS_LIBS"
> AC_SUBST([XNEST_LIBS])
> AC_SUBST([XNEST_SYS_LIBS])
> diff --git a/dix/Makefile.am b/dix/Makefile.am
> index 5e2dad7..49e41d0 100644
> --- a/dix/Makefile.am
> +++ b/dix/Makefile.am
> @@ -8,6 +8,7 @@ libmain_la_SOURCES = \
> libdix_la_SOURCES = \
> atom.c \
> colormap.c \
> + client.c \
> cursor.c \
> deprecated.c \
> devices.c \
> diff --git a/dix/client.c b/dix/client.c
> new file mode 100644
> index 0000000..1016a56
> --- /dev/null
> +++ b/dix/client.c
> @@ -0,0 +1,345 @@
> +/*
> + * 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. Use GetClient* to query information and
> + * GetClientIds*Cbs to register for notifications.
> + *
> + * Author: Rami Ylimäki <rami.ylimaki at vincit.fi>
> + */
> +
> +#include "client.h"
> +
> +#ifdef CLIENTIDS
> +
> +#include "os.h"
> +#include "dixstruct.h"
> +
> +/* Key for identifying ID information for a client. */
> +static DevPrivateKeyRec ClientIdsPrivKeyRec;
> +static DevPrivateKey ClientIdsPrivKey = &ClientIdsPrivKeyRec;
> +
> +/**
> + * @return Client private holding PID and command line string. Error
> + * (NULL) if PID is not available for the client.
> + */
> +ClientIdsPrivatePtr GetClientIds(ClientPtr client)
> +{
> + PrivatePtr *privates = &(client)->devPrivates;
> + pointer priv = dixLookupPrivate(privates, ClientIdsPrivKey);
> + return (ClientIdsPrivatePtr) priv;
> +}
> +
> +/* Called after PID and command line string have been determined for a
> + * client (all clients, including remote clients, except server
> + * client). You may call GetClientPid and GetClientCmd after this
> + * notification. */
> +static CallbackListPtr ClientIdsReservedCbs = NULL;
> +
> +/**
> + * @return Publisher of client ID allocation notifications.
> + *
> + * @see AddCallback
> + */
> +CallbackListPtr *GetClientIdsReservedCbs(void)
> +{
> + return &ClientIdsReservedCbs;
> +}
> +
> +/* Called before PID and command line string will be invalidated for a
> + * client (all clients, including remote clients, except server
> + * client). GetClientPid and GetClientCmd will return errors when
> + * called after this notification. */
> +static CallbackListPtr ClientIdsReleasedCbs = NULL;
> +
> +/**
> + * @return Publisher of client ID deallocation notifications.
> + *
> + * @see AddCallback
> + */
> +CallbackListPtr *GetClientIdsReleasedCbs(void)
> +{
> + return &ClientIdsReleasedCbs;
> +}
> +
> +/**
> + * 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
> + */
> +static pid_t DetermineClientPid(ClientPtr client)
> +{
> + /* The implementation is essentially a wrapper. However, we wan't
> + * to keep the wrapper for documentation purposes since it
> + * clarifies the intended usage pattern. */
> + return GetPidFromClient(client);
> +}
> +
> +/**
> + * 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 GetClientCmd to determine the string at
> + * other times.
> + *
> + * @param[in] pid Process ID of a client.
> + *
> + * @return Client command line string. Error (NULL) if command line
> + * string can't be determined for the client. You must release
> + * the string by calling free when it's not used anymore.
> + *
> + * @see GetClientCmd
> + */
> +static const char *DetermineClientCmd(pid_t pid)
> +{
> + /* The implementation is essentially a wrapper. However, we wan't
> + * to keep the wrapper for documentation purposes since it
> + * clarifies the intended usage pattern. */
> + return GetCommandFromPid(pid);
> +}
> +
> +/**
> + * Called when a new client connects. Allocates a private for the
> + * client and fills it with ID information.
> + *
> + * @param[in] client Recently connected client.
> + */
> +static void ReserveClientIds(ClientPtr client)
> +{
> + ClientIdsPrivatePtr priv = NULL;
> + pid_t pid = -1;
> +
> + if (client == NullClient)
> + return;
> +
> + /* Allocate private structure only if PID is available. */
> + pid = DetermineClientPid(client);
> + if (pid != -1)
> + {
> + priv = malloc(sizeof(ClientIdsPrivateRec));
> + if (priv)
> + {
> + priv->pid = pid;
> + priv->cmdline = DetermineClientCmd(pid);
> + }
> + }
> +
> + DebugF("client(%lx): Reserved pid(%d).\n",
> + client->clientAsMask, priv ? priv->pid : -1);
> + DebugF("client(%lx): Reserved cmdline(%s).\n",
> + client->clientAsMask, (priv && priv->cmdline) ? priv->cmdline : "NULL");
> +
> + dixSetPrivate(&(client)->devPrivates, ClientIdsPrivKey, priv);
> +}
> +
> +/**
> + * Called when an existing client disconnects. Frees client ID
> + * information as well as the client private.
> + *
> + * @param[in] client Recently disconnected client.
> + */
> +static void ReleaseClientIds(ClientPtr client)
> +{
> + ClientIdsPrivatePtr priv = NULL;
> +
> + if (client == NullClient)
> + return;
> +
> + priv = GetClientIds(client);
> + if (!priv)
> + return;
> +
> + DebugF("client(%lx): Released pid(%d).\n",
> + client->clientAsMask, priv ? priv->pid : -1);
> + DebugF("client(%lx): Released cmdline(%s).\n",
> + client->clientAsMask, (priv && priv->cmdline) ? priv->cmdline : "NULL");
> +
> + free((void *) priv->cmdline); /* const char * */
> + free(priv);
> + dixSetPrivate(&(client)->devPrivates, ClientIdsPrivKey, NULL);
> +}
> +
> +/**
> + * Called when new client connects or existing client disconnects.
> + *
> + * @param[in] pcbl Publisher of client state change notifications.
> + * @param[in] nulldata Unused private callback data.
> + * @param[in] calldata Information about client whose state changed.
> + *
> + * @see GetClientIdsReservedCbs
> + * @see GetClientIdsReleasedCbs
> + */
> +static void ClientIdsChanged(CallbackListPtr *pcbl, pointer nulldata, pointer calldata)
> +{
> + NewClientInfoRec *pci = (NewClientInfoRec *)calldata;
> + ClientPtr client = pci->client;
> +
> + switch (client->clientState)
> + {
> + case ClientStateGone:
> + case ClientStateRetained:
> + /* Notify subscribers that client IDs will be released before
> + * they are actually released. */
> + CallCallbacks(&ClientIdsReleasedCbs, client);
> + ReleaseClientIds(client);
> + break;
> + case ClientStateInitial:
> + /* Reserve client IDs and notify subscribers about new IDs
> + * afterwards. */
> + ReserveClientIds(client);
> + CallCallbacks(&ClientIdsReservedCbs, client);
> + break;
> + default:
> + break;
> + }
> +}
> +
> +/**
> + * Starts tracking of client connections and disconnections. After
> + * initialization, PID and command line strings are determined and
> + * cached for each connected client. Call this before any clients have
> + * connected.
> + *
> + * @param[in] server Recently initialized server client.
> + */
> +void InitClientIds(ClientPtr server)
> +{
> + if (!dixRegisterPrivateKey(ClientIdsPrivKey, PRIVATE_CLIENT, 0))
> + FatalError("Can't register client IDs private.\n");
> +
> + if (!AddCallback(&ClientStateCallback, ClientIdsChanged, NULL))
> + FatalError("Can't track client IDs.\n");
> +
> + ReserveClientIds(server);
> +}
> +
> +/**
> + * Stops tracking clients. Call this after all clients have
> + * disconnected.
> + *
> + * @param[in] server Server client that is about to be cleaned up.
> + */
> +void CloseClientIds(ClientPtr server)
> +{
> + if (!DeleteCallback(&ClientStateCallback, ClientIdsChanged, NULL))
> + LogMessage(X_ERROR, "Can't stop tracking client IDs.\n");
> +
> + DeleteCallbackList(&ClientIdsReservedCbs);
> + DeleteCallbackList(&ClientIdsReleasedCbs);
> +
> + ReleaseClientIds(server);
> +}
> +
> +/**
> + * 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 ClientIdsReservedCbs notification
> + * - after ClientIdsReleasedCbs notification
> + * - for remote clients
> + *
> + * @see DetermineClientPid
> + */
> +pid_t GetClientPid(ClientPtr client)
> +{
> + ClientIdsPrivatePtr priv = NULL;
> +
> + if (client == NullClient)
> + return -1;
> +
> + priv = GetClientIds(client);
> + if (!priv)
> + return -1;
> +
> + return priv->pid;
> +}
> +
> +/**
> + * Get cached command line string of a client.
> + *
> + * param[in] client Client whose command line string caching has been
> + * attempted previously.
> + *
> + * @return Cached client command line. Error (NULL) if called:
> + * - before ClientIdsReservedCbs notification
> + * - after ClientIdsReleasedCbs notification
> + * - for remote clients
> + * - on OS that doesn't support mapping of PID to command line
> + *
> + * @see DetermineClientCmd
> + */
> +const char *GetClientCmd(ClientPtr client)
> +{
> + ClientIdsPrivatePtr priv = NULL;
> +
> + if (client == NullClient)
> + return NULL;
> +
> + priv = GetClientIds(client);
> + if (!priv)
> + return NULL;
> +
> + return priv->cmdline;
> +}
> +
> +#else /* CLIENTIDS */
> +
> +void InitClientIds(ClientPtr server)
> +{
> +}
> +
> +void CloseClientIds(ClientPtr server)
> +{
> +}
> +
> +#endif /* CLIENTIDS */
> diff --git a/dix/main.c b/dix/main.c
> index 5c46dc1..b46433b 100644
> --- a/dix/main.c
> +++ b/dix/main.c
> @@ -104,6 +104,7 @@ Equipment Corporation.
> #include "extnsionst.h"
> #include "privates.h"
> #include "registry.h"
> +#include "client.h"
> #ifdef PANORAMIX
> #include "panoramiXsrv.h"
> #else
> @@ -260,6 +261,7 @@ int main(int argc, char *argv[], char *envp[])
> InitCoreDevices();
> InitInput(argc, argv);
> InitAndStartDevices();
> + InitClientIds(serverClient);
>
> dixSaveScreens(serverClient, SCREEN_SAVER_FORCER, ScreenSaverReset);
>
> @@ -325,6 +327,7 @@ int main(int argc, char *argv[], char *envp[])
> screenInfo.numScreens = i;
> }
>
> + CloseClientIds(serverClient);
> dixFreePrivates(serverClient->devPrivates, PRIVATE_CLIENT);
> serverClient->devPrivates = NULL;
>
> diff --git a/hw/xfree86/loader/sdksyms.sh b/hw/xfree86/loader/sdksyms.sh
> index 13c5ae5..6463182 100755
> --- a/hw/xfree86/loader/sdksyms.sh
> +++ b/hw/xfree86/loader/sdksyms.sh
> @@ -264,6 +264,7 @@ cat > sdksyms.c << EOF
> #include "colormap.h"
> #include "colormapst.h"
> #include "hotplug.h"
> +#include "client.h"
> #include "cursor.h"
> #include "cursorstr.h"
> #include "dix.h"
> diff --git a/include/Makefile.am b/include/Makefile.am
> index e76de05..06cf46f 100644
> --- a/include/Makefile.am
> +++ b/include/Makefile.am
> @@ -4,6 +4,7 @@ sdk_HEADERS = \
> bstore.h \
> bstorestr.h \
> callback.h \
> + client.h \
> closestr.h \
> closure.h \
> colormap.h \
> diff --git a/include/client.h b/include/client.h
> new file mode 100644
> index 0000000..2a1387b
> --- /dev/null
> +++ b/include/client.h
> @@ -0,0 +1,60 @@
> +/*
> + * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). 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.
> + */
> +
> +/* Author: Rami Ylimäki <rami.ylimaki at vincit.fi> */
> +
> +#ifndef CLIENT_H
> +#define CLIENT_H
> +
> +#ifdef HAVE_DIX_CONFIG_H
> +#include <dix-config.h>
> +#endif
> +#include "dix.h"
> +
> +/* Initialize and clean up. */
> +void InitClientIds(ClientPtr server);
> +void CloseClientIds(ClientPtr server);
> +
> +#ifdef CLIENTIDS /* whether configured with client ID tracking */
> +
> +#include <sys/types.h>
> +
> +/* Client specific ID information. The corresponding client private
> + * will be NULL if PID is not available for the client. */
> +typedef struct
> +{
> + pid_t pid; /* always zero or positive */
> + const char *cmdline; /* NULL if not available */
> +} ClientIdsPrivateRec, *ClientIdsPrivatePtr;
> +
> +/* Register to notifications. */
> +extern _X_EXPORT CallbackListPtr *GetClientIdsReservedCbs(void);
> +extern _X_EXPORT CallbackListPtr *GetClientIdsReleasedCbs(void);
> +
> +/* Query client IDs. */
> +extern _X_EXPORT ClientIdsPrivatePtr GetClientIds(ClientPtr client);
> +extern _X_EXPORT pid_t GetClientPid(ClientPtr client);
> +extern _X_EXPORT const char *GetClientCmd(ClientPtr client);
> +
> +#endif /* CLIENTIDS */
> +#endif /* CLIENT_H */
> diff --git a/include/dix-config.h.in b/include/dix-config.h.in
> index 6a33264..c7c01dc 100644
> --- a/include/dix-config.h.in
> +++ b/include/dix-config.h.in
> @@ -276,6 +276,9 @@
> /* Support X resource extension */
> #undef RES
>
> +/* Support client ID tracking in X resource extension */
> +#undef CLIENTIDS
> +
> /* Support MIT-SCREEN-SAVER extension */
> #undef SCREENSAVER
>
> diff --git a/include/os.h b/include/os.h
> index efa202c..81f6f98 100644
> --- a/include/os.h
> +++ b/include/os.h
> @@ -51,6 +51,7 @@ SOFTWARE.
>
> #include "misc.h"
> #include <stdarg.h>
> +#include <sys/types.h> /* pid_t */
>
> #define SCREEN_SAVER_ON 0
> #define SCREEN_SAVER_OFF 1
> @@ -369,6 +370,8 @@ typedef struct {
>
> extern _X_EXPORT int GetLocalClientCreds(ClientPtr, LocalClientCredRec **);
> extern _X_EXPORT void FreeLocalClientCreds(LocalClientCredRec *);
> +extern _X_EXPORT pid_t GetPidFromClient(ClientPtr client);
> +extern _X_EXPORT const char *GetCommandFromPid(pid_t pid);
>
> extern _X_EXPORT int ChangeAccessControl(ClientPtr /*client*/, int /*fEnabled*/);
>
> diff --git a/os/access.c b/os/access.c
> index 0279259..50cd127 100644
> --- a/os/access.c
> +++ b/os/access.c
> @@ -1297,6 +1297,82 @@ FreeLocalClientCreds(LocalClientCredRec *lcc)
> }
> }
>
> +/**
> + * Find out the PID of a client.
> + *
> + * @param[in] client Any null, server, local or remote client.
> + *
> + * @return PID of given client. Error (-1) if the PID is not
> + * available, which is the case for remote clients for
> + * example.
> + */
> +pid_t GetPidFromClient(ClientPtr 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;
> +}
> +
> +/**
> + * Map a client PID to a command line string. Currently only systems
> + * with /proc/pid/cmdline are supported.
> + *
> + * @param[in] pid Process ID of a client.
> + *
> + * @return Command line string of the given process. Error (NULL) if
> + * the command line string can't be determined from the
> + * PID. You must release the string by calling free when it's
> + * not used anymore.
> + */
> +const char *GetCommandFromPid(pid_t pid)
> +{
> + char path[PATH_MAX + 1];
> + char *cmd = NULL;
> + int fd = 0;
> + int bytes = 0;
> +
> + if (pid == -1)
> + return NULL;
> +
> + if (snprintf(path, sizeof(path), "/proc/%d/cmdline", pid) < 0)
> + return NULL;
> +
> + fd = open(path, O_RDONLY);
> + if (fd < 0)
> + return NULL;
> + bytes = read(fd, path, sizeof(path));
> + if (bytes <= 0)
> + return NULL;
> + if (close(fd) < 0)
> + return NULL;
> +
> + /* We are only interested in the process name. We don't care about
> + * its arguments. Allocate space only for the process name. */
> + path[bytes - 1] = '\0';
> + bytes = strlen(path) + 1;
> + cmd = malloc(bytes);
> + if (cmd == NULL)
> + return NULL;
> + strncpy(cmd, path, bytes);
> + cmd[bytes - 1] = '\0';
> +
> + return cmd;
> +}
> +
> static int
> AuthorizedClient(ClientPtr client)
> {
> --
> 1.6.3.3
>
Tiago
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