src/ap/steering.c - vendor/opensource/hostap - Git at Google

 /*
  * hostapd / Interface steering
  * Copyright (c) 2015 Google, Inc.
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
  */

 #include "includes.h"

 #include <sys/stat.h>
 #include <unistd.h>
 #include <dirent.h>
 #include "common.h"
 #include "common/defs.h"
 #include "common/hw_features_common.h"
 #include "common/ieee802_11_defs.h"
 #include "hostapd.h"
 #include "steering.h"

 static int get_timestamp_filename(const u8 *mac,
                                   logged_request_type type,
                                   steering_path_type path_type, char *buf,
                                   size_t len) {
   char *path = (path_type == STEERING_PATH ?
                 steering_timestamp_path : request_logging_path);

 	if (path == NULL) {
 		return 0;
 	}

 	if (os_snprintf(buf, len, "%s/" COMPACT_MACSTR ".%d", path,
 	                MAC2STR(mac), type) < 0) {
 		wpa_printf(MSG_ERROR, "os_snprintf couldn't format filename: %s",
 		           strerror(errno));
 		return 0;
 	}

 	return 1;
 }

 int write_timestamp_file(const u8 *mac,
                          const struct hostapd_data *hapd,
                          logged_request_type type,
                          const struct os_reltime *timestamp) {
 	FILE *f;
 	char filename[1024], tmp_filename[1024];
 	int success = 0;

 	if (!get_timestamp_filename(mac, type, LOGGING_PATH, filename,
 	                            sizeof(filename))) {
 		return 0;
 	}

 	/* Create a temporary filename to prevent multiple interfaces on the same band
 	 * from touching each others' writes.
 	 */
 	if (os_snprintf(tmp_filename, sizeof(tmp_filename), "%s%s", filename,
 	                os_strrchr(hapd->iface->config_fname, '.')) < 0) {
 		wpa_printf(MSG_ERROR, "os_snprintf couldn't format temp filename: %s",
 		           strerror(errno));
 		return 0;
 	}

 	if ((f = fopen(tmp_filename, "w")) == NULL) {
 		wpa_printf(MSG_ERROR, "fopen(%s) for write: %s", tmp_filename,
 		           strerror(errno));
 		return 0;
 	}

 	if (timestamp) {
 		if (fprintf(f, "%d %d", timestamp->sec, timestamp->usec) < 0) {
 			wpa_printf(MSG_ERROR, "fprintf to %s: %s", tmp_filename, strerror(errno));
 		} else {
 			success = 1;
 		}
 	}

 	if (fclose(f) == EOF) {
 		wpa_printf(MSG_ERROR, "fclose(%s): %s", tmp_filename, strerror(errno));
 		return 0;
 	}

 	if (rename(tmp_filename, filename) != 0) {
 		wpa_printf(MSG_ERROR, "rename(%s, %s): %s", tmp_filename, filename,
 		           strerror(errno));
 		return 0;
 	}

 	return success;
 }

 int maybe_write_timestamp_file(const u8 *mac,
                                const struct hostapd_data *hapd,
                                logged_request_type type) {
 	struct os_reltime now, prev_logged_timestamp, new_timestamp;
 	int bandsteering_delay_seconds;
 	if (!request_logging_path) {
 		return 0;
 	}

 	os_get_reltime(&now);
 	if (garbage_collect_timestamp_files() == -1) {
 		wpa_printf(MSG_ERROR,
 		           "Garbage collecting steering timestamp files failed: %s",
 		           strerror(errno));
 		return 0;
 	}
 	if (!read_timestamp_file(mac, type, LOGGING_PATH, &prev_logged_timestamp) ||
 	    os_reltime_expired(&now, &prev_logged_timestamp,
 	                       BANDSTEERING_EXPIRATION_SECONDS)) {
 		bandsteering_delay_seconds = BANDSTEERING_DELAY_SECONDS;
 		if (experiment("WifiShortBandsteeringDelay")) {
 			bandsteering_delay_seconds = 1;
 		}
 		new_timestamp.sec = now.sec + bandsteering_delay_seconds;
 		new_timestamp.usec = now.usec;
 		if (!write_timestamp_file(mac, hapd, type, &new_timestamp)) {
 			wpa_printf(MSG_ERROR, "Failed to write timestamp file.");
 			return 0;
 		} else {
 			wpa_printf(MSG_INFO, "Set steering timestamp for " MACSTR " (type=%d)",
 			           MAC2STR(mac), type);
 			return 1;
 		}
 	}
 }

 int read_timestamp_file(const u8 *mac,
                         logged_request_type type,
                         steering_path_type path_type,
                         struct os_reltime *timestamp) {
 	FILE *f;
 	char filename[1024];
 	int success = 1;
 	struct stat st;
 	os_time_t sec = 0, usec = 0;

 	if (!get_timestamp_filename(mac, type, path_type, filename,
 	                            sizeof(filename))) {
 		return 0;
 	}

 	if (stat(filename, &st) == -1) {
 		return 0;
 	}

 	f = fopen(filename, "r");
 	if (f == NULL) {
 		wpa_printf(MSG_ERROR, "open(%s) for read: %s", filename, strerror(errno));
 		return 0;
 	}

 	if (timestamp) {
 		if (fscanf(f, "%d %d", &timestamp->sec, &timestamp->usec) != 2) {
 			wpa_printf(MSG_ERROR, "fscanf from %s: %s", filename, strerror(errno));
 			success = 0;
 		}
 	}

 	if (fclose(f) == EOF) {
 		wpa_printf(MSG_ERROR, "fclose(%s): %s", filename, strerror(errno));
 		return 0;
 	}

 	return success;
 }

 int delete_timestamp_file(const u8 *mac,
                           logged_request_type type,
                           steering_path_type path_type) {
 	char filename[1024];
 	struct stat st;

 	if (!get_timestamp_filename(mac, type, path_type, filename,
 	                            sizeof(filename))) {
 		return 0;
 	}

 	if (stat(filename, &st) == -1) {
 		return 1;
 	}

 	if (unlink(filename) == -1) {
 		wpa_printf(MSG_ERROR, "unlink(%s): %s", filename, strerror(errno));
 		return 0;
 	}

 	return 1;
 }

 int file_ctime_lt(const struct dirent **a, const struct dirent **b) {
 	struct stat astat, bstat;

 	/* If we can't stat both of the files, give up and say they're equivalent. */
 	if (stat((*a)->d_name, &astat) == -1 || stat((*b)->d_name, &bstat) == -1) {
 		return 0;
 	}

 	return astat.st_ctime - bstat.st_ctime;
 }

 /* Only garbage collect LOG_PROBE files. */
 int should_garbage_collect(const struct dirent *name) {
 	char *extension = os_strrchr(name->d_name, '.');
 	char buf[4];
 	os_snprintf(buf, sizeof(buf), ".%d", LOG_PROBE);

 	return os_strncmp(extension, buf, sizeof(buf)) == 0;
 }

 int garbage_collect_timestamp_files(const char *path) {
 	int num_timestamp_files = 0, num_timestamp_files_deleted = 0, i = 0;
 	struct dirent **namelist;
 	char original_cwd[1024];
 	char *filename;
 	int error = 0;

 	if (getcwd(original_cwd, sizeof(original_cwd)) == NULL) {
 		wpa_printf(MSG_ERROR, "getcwd(): %s", strerror(errno));
 		return -1;
 	}

 	if (chdir(request_logging_path) == -1) {
 		if (errno != ENOENT) {
 			wpa_printf(MSG_ERROR, "chdir(%s): %s",
 			           request_logging_path, strerror(errno));
 			return -1;
 		} else {
 			return 0;
 		}
 	}

 	num_timestamp_files = scandir(request_logging_path, &namelist,
 	                              should_garbage_collect, file_ctime_lt);
 	for (i = 0; i < num_timestamp_files; ++i) {
 		if (MAX_STEERING_TIMESTAMP_FILES <
 		    /* The -2 is because scandir includes "." and "..". */
 		    (num_timestamp_files - 2) - num_timestamp_files_deleted) {
 			filename = namelist[i]->d_name;
 			if (filename[0] != '.' && !error) {
 				if (unlink(filename) == -1) {
 					wpa_printf(MSG_ERROR, "unlink(%s): %s", filename, strerror(errno));
 					error = 1;
 				} else {
 					++num_timestamp_files_deleted;
 				}
 			}
 		}
 		os_free(namelist[i]);
 	}
 	os_free(namelist);

 	if (chdir(original_cwd) == -1) {
 		wpa_printf(MSG_ERROR, "chdir(%s): %s", original_cwd, strerror(errno));
 		return -1;
 	}

 	return error ? -1 : num_timestamp_files_deleted;
 }
	/*
	* hostapd / Interface steering
	* Copyright (c) 2015 Google, Inc.
	*
	* This software may be distributed under the terms of the BSD license.
	* See README for more details.
	*/

	#include "includes.h"

	#include <sys/stat.h>
	#include <unistd.h>
	#include <dirent.h>
	#include "common.h"
	#include "common/defs.h"
	#include "common/hw_features_common.h"
	#include "common/ieee802_11_defs.h"
	#include "hostapd.h"
	#include "steering.h"

	static int get_timestamp_filename(const u8 *mac,
	logged_request_type type,
	steering_path_type path_type, char *buf,
	size_t len) {
	char *path = (path_type == STEERING_PATH ?
	steering_timestamp_path : request_logging_path);

	if (path == NULL) {
	return 0;
	}

	if (os_snprintf(buf, len, "%s/" COMPACT_MACSTR ".%d", path,
	MAC2STR(mac), type) < 0) {
	wpa_printf(MSG_ERROR, "os_snprintf couldn't format filename: %s",
	strerror(errno));
	return 0;
	}

	return 1;
	}

	int write_timestamp_file(const u8 *mac,
	const struct hostapd_data *hapd,
	logged_request_type type,
	const struct os_reltime *timestamp) {
	FILE *f;
	char filename[1024], tmp_filename[1024];
	int success = 0;

	if (!get_timestamp_filename(mac, type, LOGGING_PATH, filename,
	sizeof(filename))) {
	return 0;
	}

	/* Create a temporary filename to prevent multiple interfaces on the same band
	* from touching each others' writes.
	*/
	if (os_snprintf(tmp_filename, sizeof(tmp_filename), "%s%s", filename,
	os_strrchr(hapd->iface->config_fname, '.')) < 0) {
	wpa_printf(MSG_ERROR, "os_snprintf couldn't format temp filename: %s",
	strerror(errno));
	return 0;
	}

	if ((f = fopen(tmp_filename, "w")) == NULL) {
	wpa_printf(MSG_ERROR, "fopen(%s) for write: %s", tmp_filename,
	strerror(errno));
	return 0;
	}

	if (timestamp) {
	if (fprintf(f, "%d %d", timestamp->sec, timestamp->usec) < 0) {
	wpa_printf(MSG_ERROR, "fprintf to %s: %s", tmp_filename, strerror(errno));
	} else {
	success = 1;
	}
	}

	if (fclose(f) == EOF) {
	wpa_printf(MSG_ERROR, "fclose(%s): %s", tmp_filename, strerror(errno));
	return 0;
	}

	if (rename(tmp_filename, filename) != 0) {
	wpa_printf(MSG_ERROR, "rename(%s, %s): %s", tmp_filename, filename,
	strerror(errno));
	return 0;
	}

	return success;
	}

	int maybe_write_timestamp_file(const u8 *mac,
	const struct hostapd_data *hapd,
	logged_request_type type) {
	struct os_reltime now, prev_logged_timestamp, new_timestamp;
	int bandsteering_delay_seconds;
	if (!request_logging_path) {
	return 0;
	}

	os_get_reltime(&now);
	if (garbage_collect_timestamp_files() == -1) {
	wpa_printf(MSG_ERROR,
	"Garbage collecting steering timestamp files failed: %s",
	strerror(errno));
	return 0;
	}
	if (!read_timestamp_file(mac, type, LOGGING_PATH, &prev_logged_timestamp) \|\|
	os_reltime_expired(&now, &prev_logged_timestamp,
	BANDSTEERING_EXPIRATION_SECONDS)) {
	bandsteering_delay_seconds = BANDSTEERING_DELAY_SECONDS;
	if (experiment("WifiShortBandsteeringDelay")) {
	bandsteering_delay_seconds = 1;
	}
	new_timestamp.sec = now.sec + bandsteering_delay_seconds;
	new_timestamp.usec = now.usec;
	if (!write_timestamp_file(mac, hapd, type, &new_timestamp)) {
	wpa_printf(MSG_ERROR, "Failed to write timestamp file.");
	return 0;
	} else {
	wpa_printf(MSG_INFO, "Set steering timestamp for " MACSTR " (type=%d)",
	MAC2STR(mac), type);
	return 1;
	}
	}
	}

	int read_timestamp_file(const u8 *mac,
	logged_request_type type,
	steering_path_type path_type,
	struct os_reltime *timestamp) {
	FILE *f;
	char filename[1024];
	int success = 1;
	struct stat st;
	os_time_t sec = 0, usec = 0;

	if (!get_timestamp_filename(mac, type, path_type, filename,
	sizeof(filename))) {
	return 0;
	}

	if (stat(filename, &st) == -1) {
	return 0;
	}

	f = fopen(filename, "r");
	if (f == NULL) {
	wpa_printf(MSG_ERROR, "open(%s) for read: %s", filename, strerror(errno));
	return 0;
	}

	if (timestamp) {
	if (fscanf(f, "%d %d", &timestamp->sec, &timestamp->usec) != 2) {
	wpa_printf(MSG_ERROR, "fscanf from %s: %s", filename, strerror(errno));
	success = 0;
	}
	}

	if (fclose(f) == EOF) {
	wpa_printf(MSG_ERROR, "fclose(%s): %s", filename, strerror(errno));
	return 0;
	}

	return success;
	}

	int delete_timestamp_file(const u8 *mac,
	logged_request_type type,
	steering_path_type path_type) {
	char filename[1024];
	struct stat st;

	if (!get_timestamp_filename(mac, type, path_type, filename,
	sizeof(filename))) {
	return 0;
	}

	if (stat(filename, &st) == -1) {
	return 1;
	}

	if (unlink(filename) == -1) {
	wpa_printf(MSG_ERROR, "unlink(%s): %s", filename, strerror(errno));
	return 0;
	}

	return 1;
	}

	int file_ctime_lt(const struct dirent a, const struct dirent b) {
	struct stat astat, bstat;

	/* If we can't stat both of the files, give up and say they're equivalent. */
	if (stat((a)->d_name, &astat) == -1 \|\| stat((b)->d_name, &bstat) == -1) {
	return 0;
	}

	return astat.st_ctime - bstat.st_ctime;
	}

	/* Only garbage collect LOG_PROBE files. */
	int should_garbage_collect(const struct dirent *name) {
	char *extension = os_strrchr(name->d_name, '.');
	char buf[4];
	os_snprintf(buf, sizeof(buf), ".%d", LOG_PROBE);

	return os_strncmp(extension, buf, sizeof(buf)) == 0;
	}

	int garbage_collect_timestamp_files(const char *path) {
	int num_timestamp_files = 0, num_timestamp_files_deleted = 0, i = 0;
	struct dirent **namelist;
	char original_cwd[1024];
	char *filename;
	int error = 0;

	if (getcwd(original_cwd, sizeof(original_cwd)) == NULL) {
	wpa_printf(MSG_ERROR, "getcwd(): %s", strerror(errno));
	return -1;
	}

	if (chdir(request_logging_path) == -1) {
	if (errno != ENOENT) {
	wpa_printf(MSG_ERROR, "chdir(%s): %s",
	request_logging_path, strerror(errno));
	return -1;
	} else {
	return 0;
	}
	}

	num_timestamp_files = scandir(request_logging_path, &namelist,
	should_garbage_collect, file_ctime_lt);
	for (i = 0; i < num_timestamp_files; ++i) {
	if (MAX_STEERING_TIMESTAMP_FILES <
	/* The -2 is because scandir includes "." and "..". */
	(num_timestamp_files - 2) - num_timestamp_files_deleted) {
	filename = namelist[i]->d_name;
	if (filename[0] != '.' && !error) {
	if (unlink(filename) == -1) {
	wpa_printf(MSG_ERROR, "unlink(%s): %s", filename, strerror(errno));
	error = 1;
	} else {
	++num_timestamp_files_deleted;
	}
	}
	}
	os_free(namelist[i]);
	}
	os_free(namelist);

	if (chdir(original_cwd) == -1) {
	wpa_printf(MSG_ERROR, "chdir(%s): %s", original_cwd, strerror(errno));
	return -1;
	}

	return error ? -1 : num_timestamp_files_deleted;
	}