X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=afs.c;h=c726f35f6a3524fa56a8934ae660d62472c8bf45;hp=b5cf9f792e955d8c7df53483a3aeb7ec6970d1a1;hb=aea0aba712b2170e2d39ffa1c8f8cb55fc0881bf;hpb=df18715e70c9d5c096a536435e5959d0d7d4ba56;ds=sidebyside diff --git a/afs.c b/afs.c index b5cf9f79..c726f35f 100644 --- a/afs.c +++ b/afs.c @@ -1,11 +1,19 @@ +/* + * Copyright (C) 2007 Andre Noll + * + * Licensed under the GPL v2. For licencing details see COPYING. + */ + +/** \file afs.c Paraslash's audio file selector. */ + +#include "server.cmdline.h" #include "para.h" #include "afh.h" +#include "server.h" #include "error.h" #include /* readdir() */ #include #include -//#include - #include "net.h" #include "afs.h" #include "ipc.h" @@ -15,31 +23,7 @@ #include "signal.h" #include "fd.h" -/** \file afs.c Paraslash's audio file selector. */ - -/** - * Compare two osl objects of string type. - * - * \param obj1 Pointer to the first object. - * \param obj2 Pointer to the second object. - * - * In any case, only \p MIN(obj1->size, obj2->size) characters of each string - * are taken into account. - * - * \return It returns an integer less than, equal to, or greater than zero if - * \a obj1 is found, respectively, to be less than, to match, or be greater than - * obj2. - * - * \sa strcmp(3), strncmp(3), osl_compare_func. - */ -int string_compare(const struct osl_object *obj1, const struct osl_object *obj2) -{ - const char *str1 = (const char *)obj1->data; - const char *str2 = (const char *)obj2->data; - return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size)); -} - -/** The osl tables used by afs. \sa blob.c */ +/** The osl tables used by afs. \sa blob.c. */ enum afs_table_num { /** Contains audio file information. See aft.c. */ TBLNUM_AUDIO_FILES, @@ -81,69 +65,40 @@ struct command_task { struct task task; }; - /** - * A wrapper for strtol(3). - * - * \param str The string to be converted to a long integer. - * \param result The converted value is stored here. + * A random number used to "authenticate" the connection. * - * \return Positive on success, -E_ATOL on errors. - * - * \sa strtol(3), atoi(3). + * para_server picks this number by random before forking the afs process. The + * command handlers write this number together with the id of the shared memory + * area containing the query. This way, a malicious local user has to know this + * number to be able to cause the afs process to crash by sending fake queries. */ -int para_atol(const char *str, long *result) -{ - char *endptr; - long val; - int ret, base = 10; - - errno = 0; /* To distinguish success/failure after call */ - val = strtol(str, &endptr, base); - ret = -E_ATOL; - if (errno == ERANGE && (val == LONG_MAX || val == LONG_MIN)) - goto out; /* overflow */ - if (errno != 0 && val == 0) - goto out; /* other error */ - if (endptr == str) - goto out; /* No digits were found */ - if (*endptr != '\0') - goto out; /* Further characters after number */ - *result = val; - ret = 1; -out: - return ret; -} +extern uint32_t afs_socket_cookie; /** - * Struct to let para_server call a function specified from child context. + * Struct to let command handlers execute a callback in afs context. + * + * Commands that need to change the state of afs can't change the relevant data + * structures directly because commands are executed in a child process, i.e. + * they get their own virtual address space. + * + * This structure is used by \p send_callback_request() (executed from handler + * context) in order to let the afs process call the specified function. An + * instance of that structure is written to a shared memory area together with + * the arguments to the callback function. The identifier of the shared memory + * area is written to the command socket. * - * Commands that need to change the state of para_server can't - * change the relevant data structures directly because commands - * are executed in a child process, i.e. they get their own - * virtual address space. This structure must be used to let - * para_server (i.e. the parent process) call a function specified - * by the child (the command handler). + * The afs process accepts connections on the command socket and reads the + * shared memory id, attaches the corresponing area, calls the given handler to + * perform the desired action and to optionally compute a result. * - * \sa fork(2), ipc.c. + * The result and a \p callback_result structure is then written to another + * shared memory area. The identifier for that area is written to the handler's + * command socket, so that the handler process can read the id, attach the + * shared memory area and use the result. + * + * \sa struct callback_result. */ -struct callback_data { - /** The function to be called. */ - callback_function *handler; - /** The sma for the parameters of the callback function. */ - int query_shmid; - /** The size of the query sma. */ - size_t query_size; - /** If the callback produced a result, it is stored in this sma. */ - int result_shmid; - /** The size of the result sma. */ - size_t result_size; - /** The return value of the callback function. */ - int callback_ret; - /** The return value of the callback() procedure. */ - int sma_ret; -}; - struct callback_query { /** The function to be called. */ callback_function *handler; @@ -151,16 +106,20 @@ struct callback_query { size_t query_size; }; +/** + * Structure embedded in the result of a callback. + * + * If the callback produced a result, an instance of that structure is embeeded + * into the shared memory area holding the result, mainly to let the command + * handler know the size of the result. + * + * \sa struct callback_query. + */ struct callback_result { /** The number of bytes of the result. */ size_t result_size; }; -static struct callback_data *shm_callback_data; -static int callback_mutex; -static int child_mutex; -static int result_mutex; - /** * Ask the parent process to call a given function. * @@ -169,89 +128,92 @@ static int result_mutex; * \param result Callback result will be stored here. * * This function creates a shared memory area, copies the buffer pointed to by - * \a buf to that area and notifies the parent process that \a f should be - * called ASAP. It provides proper locking via semaphores to protect against - * concurent access to the shared memory area and against concurrent access by - * another child process that asks to call the same function. + * \a buf to that area and notifies the afs process that \a f should be + * called ASAP. * - * \return Negative, if the shared memory area could not be set up. The return - * value of the callback function otherwise. + * \return Negative, on errors, the return value of the callback function + * otherwise. * - * \sa shm_new(), shm_attach(), shm_detach(), mutex_lock(), mutex_unlock(), - * shm_destroy(), struct callback_data, send_option_arg_callback_request(), - * send_standard_callback_request(). + * \sa send_option_arg_callback_request(), send_standard_callback_request(). */ int send_callback_request(callback_function *f, struct osl_object *query, struct osl_object *result) { - struct callback_data cbd = {.handler = f}; - int ret; - void *query_sma; + struct callback_query *cq; + struct callback_result *cr; + int ret, fd = -1, query_shmid, result_shmid; + void *query_shm, *result_shm; + char buf[sizeof(afs_socket_cookie) + sizeof(int)]; +// char *tmpsocket_name; + struct sockaddr_un unix_addr; assert(query->data && query->size); - ret = shm_new(query->size); + ret = shm_new(query->size + sizeof(*cq)); if (ret < 0) return ret; - cbd.query_shmid = ret; - cbd.query_size = query->size; - ret = shm_attach(cbd.query_shmid, ATTACH_RW, &query_sma); + query_shmid = ret; + ret = shm_attach(query_shmid, ATTACH_RW, &query_shm); if (ret < 0) goto out; - memcpy(query_sma, query->data, query->size); - ret = shm_detach(query_sma); + cq = query_shm; + cq->handler = f; + cq->query_size = query->size; + + memcpy(query_shm + sizeof(*cq), query->data, query->size); + ret = shm_detach(query_shm); if (ret < 0) goto out; - /* prevent other children from interacting */ - mutex_lock(child_mutex); - /* prevent parent from messing with shm_callback_data. */ - mutex_lock(callback_mutex); - /* all three mutexes are locked, set parameters for callback */ - *shm_callback_data = cbd; - /* unblock parent */ - mutex_unlock(callback_mutex); - kill(getppid(), SIGUSR1); /* wake up parent */ - /* - * At this time only the parent can run. It will execute our callback - * and unlock the result_mutex when ready to indicate that the child - * may use the result. So let's sleep on this mutex. - */ - mutex_lock(result_mutex); - /* No need to aquire the callback mutex again */ - ret = shm_callback_data->sma_ret; - if (ret < 0) /* sma problem, callback might not have been executed */ - goto unlock_child_mutex; - if (shm_callback_data->result_shmid >= 0) { /* parent provided a result */ - void *sma; - ret = shm_attach(shm_callback_data->result_shmid, ATTACH_RO, - &sma); - if (ret >= 0) { - if (result) { /* copy result */ - result->size = shm_callback_data->result_size; - result->data = para_malloc(result->size); - memcpy(result->data, sma, result->size); - ret = shm_detach(sma); - if (ret < 0) - PARA_ERROR_LOG("can not detach result\n"); - } else - PARA_WARNING_LOG("no result pointer\n"); - } else - PARA_ERROR_LOG("attach result failed: %d\n", ret); - if (shm_destroy(shm_callback_data->result_shmid) < 0) - PARA_ERROR_LOG("destroy result failed\n"); - } else { /* no result from callback */ - if (result) { - PARA_WARNING_LOG("callback has no result\n"); - result->data = NULL; - result->size = 0; - } + + *(uint32_t *) buf = afs_socket_cookie; + *(int *) (buf + sizeof(afs_socket_cookie)) = query_shmid; + + ret = get_stream_socket(PF_UNIX); + if (ret < 0) + goto out; + fd = ret; + ret = init_unix_addr(&unix_addr, conf.afs_socket_arg); + if (ret < 0) + goto out; + ret = -E_CONNECT; + if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) < 0) /* FIXME: Use para_connect() */ + goto out; + ret = send_bin_buffer(fd, buf, sizeof(buf)); + PARA_NOTICE_LOG("bin buffer ret: %d\n", ret); + if (ret < 0) + goto out; + ret = recv_bin_buffer(fd, buf, sizeof(buf)); + PARA_NOTICE_LOG("ret: %d\n", ret); + if (ret < 0) + goto out; + if (ret != sizeof(int)) { + ret = -E_RECV; + goto out; } - ret = shm_callback_data->callback_ret; -unlock_child_mutex: - /* give other children a chance */ - mutex_unlock(child_mutex); + ret = *(int *) buf; + PARA_NOTICE_LOG("result_shmid: %d\n", ret); + if (ret <= 0) + goto out; + result_shmid = ret; + ret = shm_attach(result_shmid, ATTACH_RO, &result_shm); + if (ret >= 0) { + assert(result); + cr = result_shm; + result->size = cr->result_size; + result->data = para_malloc(result->size); + memcpy(result->data, result_shm + sizeof(*cr), result->size); + ret = shm_detach(result_shm); + if (ret < 0) + PARA_ERROR_LOG("can not detach result\n"); + } else + PARA_ERROR_LOG("attach result failed: %d\n", ret); + if (shm_destroy(result_shmid) < 0) + PARA_ERROR_LOG("destroy result failed\n"); + ret = 1; out: - if (shm_destroy(cbd.query_shmid) < 0) + if (shm_destroy(query_shmid) < 0) PARA_ERROR_LOG("%s\n", "shm destroy error"); + if (fd >= 0) + close(fd); PARA_DEBUG_LOG("callback_ret: %d\n", ret); return ret; } @@ -317,6 +279,62 @@ int send_standard_callback_request(int argc, const char **argv, return send_option_arg_callback_request(NULL, argc, argv, f, result); } +/** + * Compare two osl objects of string type. + * + * \param obj1 Pointer to the first object. + * \param obj2 Pointer to the second object. + * + * In any case, only \p MIN(obj1->size, obj2->size) characters of each string + * are taken into account. + * + * \return It returns an integer less than, equal to, or greater than zero if + * \a obj1 is found, respectively, to be less than, to match, or be greater than + * obj2. + * + * \sa strcmp(3), strncmp(3), osl_compare_func. + */ +int string_compare(const struct osl_object *obj1, const struct osl_object *obj2) +{ + const char *str1 = (const char *)obj1->data; + const char *str2 = (const char *)obj2->data; + return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size)); +} + +/** + * A wrapper for strtol(3). + * + * \param str The string to be converted to a long integer. + * \param result The converted value is stored here. + * + * \return Positive on success, -E_ATOL on errors. + * + * \sa strtol(3), atoi(3). + */ +int para_atol(const char *str, long *result) +{ + char *endptr; + long val; + int ret, base = 10; + + errno = 0; /* To distinguish success/failure after call */ + val = strtol(str, &endptr, base); + ret = -E_ATOL; + if (errno == ERANGE && (val == LONG_MAX || val == LONG_MIN)) + goto out; /* overflow */ + if (errno != 0 && val == 0) + goto out; /* other error */ + if (endptr == str) + goto out; /* No digits were found */ + if (*endptr != '\0') + goto out; /* Further characters after number */ + *result = val; + ret = 1; +out: + return ret; +} + + /* * write input from fd to dynamically allocated char array, * but maximal max_size byte. Return size. @@ -488,7 +506,7 @@ static enum play_mode init_admissible_files(void) static int setup_command_socket_or_die(void) { int ret; - char *socket_name = "/tmp/afs_command_socket"; + char *socket_name = conf.afs_socket_arg; struct sockaddr_un unix_addr; unlink(socket_name); @@ -586,7 +604,7 @@ static int call_callback(int fd, int query_shmid) struct osl_object query, result = {.data = NULL}; int result_shmid = -1, ret, ret2; - ret = shm_attach(query_shmid, ATTACH_RO, &query_shm); + ret = shm_attach(query_shmid, ATTACH_RW, &query_shm); if (ret < 0) goto out; cq = query_shm; @@ -617,7 +635,7 @@ static int call_callback(int fd, int query_shmid) ret = result_shmid; out: free(result.data); - ret2 = send_bin_buffer(fd, (char *)ret, sizeof(int)); + ret2 = send_bin_buffer(fd, (char *)&ret, sizeof(int)); if (ret < 0 || ret2 < 0) { if (result_shmid >= 0) if (shm_destroy(result_shmid) < 0) @@ -648,9 +666,10 @@ static void command_post_select(struct sched *s, struct task *t) * and para_server. */ fd = t->ret; - t->ret = recv_bin_buffer(ct->fd, buf, sizeof(buf)); + /* FIXME: This is easily dosable (peer doesn't send data) */ + t->ret = recv_bin_buffer(fd, buf, sizeof(buf)); if (t->ret < 0) { - PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret)); + PARA_NOTICE_LOG("%s (%d)\n", PARA_STRERROR(-t->ret), t->ret); t->ret = 1; goto out; } @@ -707,7 +726,6 @@ void register_tasks(uint32_t cookie) __noreturn int afs_init(uint32_t cookie, int socket_fd) { int ret; -// void *shm_area; enum play_mode current_play_mode; struct sched s; @@ -743,29 +761,6 @@ __noreturn int afs_init(uint32_t cookie, int socket_fd) s.default_timeout.tv_usec = 99 * 1000; sched(&s); -#if 0 - ret = shm_new(sizeof(struct callback_data)); - if (ret < 0) - return ret; - shmid = ret; - ret = shm_attach(shmid, ATTACH_RW, &shm_area); - if (ret < 0) - return ret; - shm_callback_data = shm_area; - ret = mutex_new(); - if (ret < 0) - return ret; - callback_mutex = ret; - ret = mutex_new(); - if (ret < 0) - return ret; - child_mutex = ret; - ret = mutex_new(); - if (ret < 0) - return ret; - result_mutex = ret; - mutex_lock(result_mutex); -#endif aft_init_error: score_shutdown(OSL_MARK_CLEAN); score_init_error: @@ -799,7 +794,7 @@ static int create_all_tables(void) } /* TODO load tables after init */ -static int com_init(__a_unused int fd, int argc, const char **argv) +int com_init(__a_unused int fd, int argc, const char **argv) { int i, j, ret; if (argc == 1) @@ -823,249 +818,3 @@ static int com_init(__a_unused int fd, int argc, const char **argv) } return 1; } - -/** Describes a command of para_server. */ -struct command { - /** The name of the command. */ - const char *name; - /** The handler function. */ - int (*handler)(int fd, int argc, const char **argv); -}; - -static struct command afs_cmds[] = { -{ - .name = "add", - .handler = com_add, -}, -{ - .name = "addlyr", - .handler = com_addlyr, -}, -{ - .name = "addimg", - .handler = com_addimg, -}, -{ - .name = "addmood", - .handler = com_addmood, -}, -{ - .name = "addpl", - .handler = com_addpl, -}, -{ - .name = "catlyr", - .handler = com_catlyr, -}, -{ - .name = "catimg", - .handler = com_catimg, -}, -{ - .name = "mvimg", - .handler = com_mvimg, -}, -{ - .name = "mvlyr", - .handler = com_mvlyr, -}, -{ - .name = "mvmood", - .handler = com_mvmood, -}, -{ - .name = "mvpl", - .handler = com_mvpl, -}, -{ - .name = "catmood", - .handler = com_catmood, -}, -{ - .name = "catpl", - .handler = com_catpl, -}, -{ - .name = "rmatt", - .handler = com_rmatt, -}, -{ - .name = "init", - .handler = com_init, -}, -{ - .name = "lsatt", - .handler = com_lsatt, -}, -{ - .name = "ls", - .handler = com_afs_ls, -}, -{ - .name = "lslyr", - .handler = com_lslyr, -}, -{ - .name = "lsimg", - .handler = com_lsimg, -}, -{ - .name = "lsmood", - .handler = com_lsmood, -}, -{ - .name = "lspl", - .handler = com_lspl, -}, -{ - .name = "setatt", - .handler = com_setatt, -}, -{ - .name = "addatt", - .handler = com_addatt, -}, -{ - .name = "rm", - .handler = com_afs_rm, -}, -{ - .name = "rmlyr", - .handler = com_rmlyr, -}, -{ - .name = "rmimg", - .handler = com_rmimg, -}, -{ - .name = "rmmood", - .handler = com_rmmood, -}, -{ - .name = "rmpl", - .handler = com_rmpl, -}, -{ - .name = "touch", - .handler = com_touch, -}, -{ - .name = NULL, -} -}; - -#if 0 -static void call_callback(void) -{ - struct osl_object query, result = {.data = NULL}; - int ret, ret2; - - shm_callback_data->result_shmid = -1; /* no result */ - ret = shm_attach(shm_callback_data->query_shmid, ATTACH_RW, - &query.data); - if (ret < 0) - goto out; - query.size = shm_callback_data->query_size; - shm_callback_data->callback_ret = shm_callback_data->handler(&query, - &result); - if (result.data && result.size) { - void *sma; - ret = shm_new(result.size); - if (ret < 0) - goto detach_query; - shm_callback_data->result_shmid = ret; - shm_callback_data->result_size = result.size; - ret = shm_attach(shm_callback_data->result_shmid, ATTACH_RW, &sma); - if (ret < 0) - goto destroy_result; - memcpy(sma, result.data, result.size); - ret = shm_detach(sma); - if (ret < 0) { - PARA_ERROR_LOG("detach result failed\n"); - goto destroy_result; - } - } - ret = 1; - goto detach_query; -destroy_result: - if (shm_destroy(shm_callback_data->result_shmid) < 0) - PARA_ERROR_LOG("destroy result failed\n"); - shm_callback_data->result_shmid = -1; -detach_query: - free(result.data); - ret2 = shm_detach(query.data); - if (ret2 < 0) { - PARA_ERROR_LOG("detach query failed\n"); - if (ret >= 0) - ret = ret2; - } -out: - if (ret < 0) - PARA_ERROR_LOG("sma error %d\n", ret); - shm_callback_data->sma_ret = ret; - shm_callback_data->handler = NULL; - mutex_unlock(result_mutex); /* wake up child */ -} - -static int got_sigchld; -static void server_loop(int child_pid) -{ -// int status; - - PARA_DEBUG_LOG("server pid: %d, child pid: %d\n", - getpid(), child_pid); - for (;;) { - mutex_lock(callback_mutex); - if (shm_callback_data->handler) - call_callback(); - mutex_unlock(callback_mutex); - usleep(100); - if (!got_sigchld) - continue; - mutex_destroy(result_mutex); - mutex_destroy(callback_mutex); - mutex_destroy(child_mutex); - afs_shutdown(OSL_MARK_CLEAN); - exit(EXIT_SUCCESS); - } -} - -int main(int argc, const char **argv) -{ - int i, ret = -E_AFS_SYNTAX; - - signal(SIGUSR1, dummy); - signal(SIGCHLD, sigchld_handler); - if (argc < 2) - goto out; - ret = setup(); -// ret = afs_init(); - if (ret < 0) { - PARA_EMERG_LOG("afs_init returned %d\n", ret); - exit(EXIT_FAILURE); - } - ret = fork(); - if (ret < 0) { - ret = -E_FORK; - goto out; - } - if (ret) - server_loop(ret); - for (i = 0; cmd[i].name; i++) { - if (strcmp(cmd[i].name, argv[1])) - continue; - ret = cmd[i].handler(1, argc - 1 , argv + 1); - goto out; - - } - PARA_ERROR_LOG("unknown command: %s\n", argv[1]); - ret = -1; -out: - if (ret < 0) - PARA_ERROR_LOG("error %d\n", ret); - else - PARA_DEBUG_LOG("%s", "success\n"); - afs_shutdown(0); - return ret < 0? EXIT_FAILURE : EXIT_SUCCESS; -} -#endif