/*
- * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
#include "signal.h"
#include "fd.h"
-extern uint32_t afs_socket_cookie;
-
-/**
- * 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,
struct task task;
};
-
/**
- * A wrapper for strtol(3).
+ * A random number used to "authenticate" the connection.
*
- * \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).
+ * 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.
- *
- * 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).
- *
- * \sa fork(2), ipc.c.
- */
struct callback_data {
/** The function to be called. */
callback_function *handler;
int sma_ret;
};
+/**
+ * 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.
+ *
+ * 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.
+ *
+ * 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_query {
/** The function to be called. */
callback_function *handler;
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.
*
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.
__noreturn int afs_init(uint32_t cookie, int socket_fd)
{
int ret;
-// void *shm_area;
enum play_mode current_play_mode;
struct sched s;
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:
projects / paraslash.git / commitdiff