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 <[email protected]> --- dix/Makefile.am | 1 + dix/client.c | 273 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/client.h | 51 ++++++++++ 3 files changed, 325 insertions(+), 0 deletions(-) create mode 100644 dix/client.c create mode 100644 include/client.h diff --git a/dix/Makefile.am b/dix/Makefile.am index 5e2dad7..bc87da5 100644 --- a/dix/Makefile.am +++ b/dix/Makefile.am @@ -7,6 +7,7 @@ libmain_la_SOURCES = \ libdix_la_SOURCES = \ atom.c \ + client.c \ colormap.c \ cursor.c \ deprecated.c \ diff --git a/dix/client.c b/dix/client.c new file mode 100644 index 0000000..de55b3e --- /dev/null +++ b/dix/client.c @@ -0,0 +1,273 @@ +/* + * Copyright (c) 2010, Nokia Corporation. + * + * 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. + */ + +#include <sys/stat.h> +#include <fcntl.h> +#include <string.h> +#include <unistd.h> + +#include "client.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) is returned 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; +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; +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. Error (0) is returned if PID can't be determined for the + * client. */ +static pid_t DetermineClientPid(ClientPtr client) +{ + LocalClientCredRec *lcc = NULL; + pid_t pid = 0; + + if (client == NullClient) + return 0; + + 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. This should be called only once when a new client has + * connected, use GetClientCmd to determine the string at other + * times. Error (NULL) is returned if command line string can't be + * determined for the client. You must release the returned string by + * calling free when it's not used anymore. */ +static const char *DetermineClientCmd(ClientPtr client, pid_t pid) +{ + char path[PATH_MAX + 1]; + char *cmd = NULL; + int fd = 0; + int bytes = 0; + + if (client == NullClient) + 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; +} + +/* Called when new client connects. Allocates client private for the + * client and fills it with ID information. */ +static void ReserveClientIds(ClientPtr client) +{ + ClientIdsPrivatePtr priv = NULL; + pid_t pid = 0; + + if (client == NullClient) + return; + + /* Allocate private structure only if PID is available. */ + pid = DetermineClientPid(client); + if (pid) + { + priv = malloc(sizeof(ClientIdsPrivateRec)); + if (priv) + { + priv->pid = pid; + priv->cmd = DetermineClientCmd(client, pid); + } + } + + DebugF("client(%lx): Reserved pid(%d).\n", + client->clientAsMask, priv ? priv->pid : 0); + DebugF("client(%lx): Reserved cmd(%s).\n", + client->clientAsMask, (priv && priv->cmd) ? priv->cmd : "NULL"); + + dixSetPrivate(&(client)->devPrivates, ClientIdsPrivKey, priv); +} + +/* Called when existing client disconnects. Frees client ID + * information as well as the client private. */ +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 : 0); + DebugF("client(%lx): Released cmd(%s).\n", + client->clientAsMask, (priv && priv->cmd) ? priv->cmd : "NULL"); + + free((void *) priv->cmd); /* const char * */ + free(priv); + dixSetPrivate(&(client)->devPrivates, ClientIdsPrivKey, NULL); +} + +/* Called when new client connects or existing client disconnects. */ +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. */ +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. */ +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. Returns error (0) if called: + * - before ClientIdsReservedCbs notification + * - after ClientIdsReleasedCbs notification + * - for remote clients */ +pid_t GetClientPid(ClientPtr client) +{ + ClientIdsPrivatePtr priv = NULL; + + if (client == NullClient) + return 0; + + priv = GetClientIds(client); + if (!priv) + return 0; + + return priv->pid; +} + +/* Get cached command line string of a client. Returns error (NULL) if + * called: + * - before ClientIdsReservedCbs notification + * - after ClientIdsReleasedCbs notification + * - for remote clients */ +const char *GetClientCmd(ClientPtr client) +{ + ClientIdsPrivatePtr priv = NULL; + + if (client == NullClient) + return NULL; + + priv = GetClientIds(client); + if (!priv) + return NULL; + + return priv->cmd; +} diff --git a/include/client.h b/include/client.h new file mode 100644 index 0000000..40811c0 --- /dev/null +++ b/include/client.h @@ -0,0 +1,51 @@ +/* + * Copyright (c) 2010, Nokia Corporation. + * + * 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. + */ + +#ifndef CLIENT_IDS_H +#define CLIENT_IDS_H + +#include <sys/types.h> + +#include "dix.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 non-zero */ + const char *cmd; /* NULL if not available */ +} ClientIdsPrivateRec, *ClientIdsPrivatePtr; + +/* Initialize and clean up. */ +void InitClientIds(ClientPtr server); +void CloseClientIds(ClientPtr server); + +/* 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 /* CLIENT_IDS_H */ -- 1.6.3.3 _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel
