text: /*
   * luci-bwc - Very simple bandwidth collector cache for LuCI realtime graphs
   *
   *   Copyright (C) 2010 Jo-Philipp Wich <jow@openwrt.org>
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * 	http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #define _BSD_SOURCE
  
  #include <stdlib.h>
  #include <stdio.h>
  #include <string.h>
  #include <stdint.h>
  #include <inttypes.h>
  #include <fcntl.h>
  #include <time.h>
  #include <errno.h>
  #include <unistd.h>
  #include <signal.h>
  #include <endian.h>
  #include <dirent.h>
  
  #include <sys/stat.h>
  #include <sys/mman.h>
  #include <sys/types.h>
  #include <arpa/inet.h>
  
  #include <dlfcn.h>
  #include <iwinfo.h>
  
  #define STEP_COUNT	60
  #define STEP_TIME	1
  #define TIMEOUT		10
  
  #define PID_PATH	"/var/run/luci-bwc.pid"
  
  #define DB_PATH		"/var/lib/luci-bwc"
  #define DB_IF_FILE	DB_PATH "/if/%s"
  #define DB_RD_FILE	DB_PATH "/radio/%s"
  #define DB_CN_FILE	DB_PATH "/connections"
  #define DB_LD_FILE	DB_PATH "/load"
  
  #define LD_SCAN_PATTERN \
  	"%f %f %f"
  
  
  struct file_map {
  	int fd;
  	int size;
  	char *mmap;
  };
  
  struct traffic_entry {
  	uint32_t time;
  	uint64_t rxb;
  	uint64_t rxp;
  	uint64_t txb;
  	uint64_t txp;
  };
  
  struct conn_entry {
  	uint32_t time;
  	uint32_t udp;
  	uint32_t tcp;
  	uint32_t other;
  };
  
  struct load_entry {
  	uint32_t time;
  	uint16_t load1;
  	uint16_t load5;
  	uint16_t load15;
  };
  
  struct radio_entry {
  	uint32_t time;
  	uint16_t rate;
  	uint8_t  rssi;
  	uint8_t  noise;
  };
  
  static int readpid(void)
  {
  	int fd;
  	int pid = -1;
  	char buf[9] = { 0 };
  
  	if ((fd = open(PID_PATH, O_RDONLY)) > -1)
  	{
  		if (read(fd, buf, sizeof(buf)))
  		{
  			buf[8] = 0;
  			pid = atoi(buf);
  		}
  
  		close(fd);
  	}
  
  	return pid;
  }
  
  static int writepid(void)
  {
  	int fd;
  	int wlen;
  	char buf[9] = { 0 };
  
  	if ((fd = open(PID_PATH, O_WRONLY | O_CREAT | O_TRUNC, 0600)) > -1)
  	{
  		wlen = snprintf(buf, sizeof(buf), "%i", getpid());
  		write(fd, buf, wlen);
  		close(fd);
  
  		return 0;
  	}
  
  	return -1;
  }
  
  static int timeout = TIMEOUT;
  static int countdown = -1;
  
  static void reset_countdown(int sig)
  {
  	countdown = timeout;
  
  }
  
  
  static char *progname;
  static int prognamelen;
  
  static struct iwinfo_ops *backend = NULL;
  
  
  static int init_directory(char *path)
  {
  	char *p = path;
  
  	for (p = &path[1]; *p; p++)
  	{
  		if (*p == '/')
  		{
  			*p = 0;
  
  			if (mkdir(path, 0700) && (errno != EEXIST))
  				return -1;
  
  			*p = '/';
  		}
  	}
  
  	return 0;
  }
  
  static int init_file(char *path, int esize)
  {
  	int i, file;
  	char buf[sizeof(struct traffic_entry)] = { 0 };
  
  	if (init_directory(path))
  		return -1;
  
  	if ((file = open(path, O_WRONLY | O_CREAT, 0600)) >= 0)
  	{
  		for (i = 0; i < STEP_COUNT; i++)
  		{
  			if (write(file, buf, esize) < 0)
  				break;
  		}
  
  		close(file);
  
  		return 0;
  	}
  
  	return -1;
  }
  
  static inline uint32_t timeof(void *entry)
  {
  	return be32toh(((struct traffic_entry *)entry)->time);
  }
  
  static int update_file(const char *path, void *entry, int esize)
  {
  	int rv = -1;
  	int file;
  	char *map;
  
  	if ((file = open(path, O_RDWR)) >= 0)
  	{
  		map = mmap(NULL, esize * STEP_COUNT, PROT_READ | PROT_WRITE,
  				   MAP_SHARED | MAP_LOCKED, file, 0);
  
  		if ((map != NULL) && (map != MAP_FAILED))
  		{
  			if (timeof(entry) > timeof(map + esize * (STEP_COUNT-1)))
  			{
  				memmove(map, map + esize, esize * (STEP_COUNT-1));
  				memcpy(map + esize * (STEP_COUNT-1), entry, esize);
  			}
  
  			munmap(map, esize * STEP_COUNT);
  
  			rv = 0;
  		}
  
  		close(file);
  	}
  
  	return rv;
  }
  
  static int mmap_file(const char *path, int esize, struct file_map *m)
  {
  	m->fd   = -1;
  	m->size = -1;
  	m->mmap = NULL;
  
  	if ((m->fd = open(path, O_RDONLY)) >= 0)
  	{
  		m->size = STEP_COUNT * esize;
  		m->mmap = mmap(NULL, m->size, PROT_READ,
  					   MAP_SHARED | MAP_LOCKED, m->fd, 0);
  
  		if ((m->mmap != NULL) && (m->mmap != MAP_FAILED))
  			return 0;
  	}
  
  	return -1;
  }
  
  static void umap_file(struct file_map *m)
  {
  	if ((m->mmap != NULL) && (m->mmap != MAP_FAILED))
  		munmap(m->mmap, m->size);
  
  	if (m->fd > -1)
  		close(m->fd);
  }
  
  static void * iw_open(void)
  {
  	void *iwlib = NULL;
  	glob_t paths;
  	int i;
  
  	if (glob("/usr/lib/libiwinfo.so*", 0, NULL, &paths) != 0)
  		return NULL;
  
  	for (i = 0; i < paths.gl_pathc && !iwlib; i++)
  		iwlib = dlopen(paths.gl_pathv[i], RTLD_LAZY | RTLD_LOCAL);
  
  	globfree(&paths);
  
  	if (!iwlib)
  		return NULL;
  	return iwlib;
  }
  
  static int iw_update(
  	void *iw, const char *ifname, uint16_t *rate, uint8_t *rssi, uint8_t *noise
  ) {
  	struct iwinfo_ops *(*probe)(const char *);
  	int val;
  
  	if (!backend)
  	{
  		probe = dlsym(iw, "iwinfo_backend");
  
  		if (!probe)
  			return 0;
  
  		backend = probe(ifname);
  
  		if (!backend)
  			return 0;
  	}
  
  	*rate = (backend->bitrate && !backend->bitrate(ifname, &val)) ? val : 0;
  	*rssi = (backend->signal && !backend->signal(ifname, &val)) ? val : 0;
  	*noise = (backend->noise && !backend->noise(ifname, &val)) ? val : 0;
  
  	return 1;
  }
  
  static void iw_close(void *iw)
  {
  	void (*finish)(void);
  
  	finish = dlsym(iw, "iwinfo_finish");
  
  	if (finish)
  		finish();
  
  	dlclose(iw);
  }
  
  
  static int update_ifstat(
  	const char *ifname, uint64_t rxb, uint64_t rxp, uint64_t txb, uint64_t txp
  ) {
  	char path[1024];
  
  	struct stat s;
  	struct traffic_entry e;
  
  	snprintf(path, sizeof(path), DB_IF_FILE, ifname);
  
  	if (stat(path, &s))
  	{
  		if (init_file(path, sizeof(struct traffic_entry)))
  		{
  			fprintf(stderr, "Failed to init %s: %s\n",
  					path, strerror(errno));
  
  			return -1;
  		}
  	}
  
  	e.time = htobe32(time(NULL));
  	e.rxb  = htobe64(rxb);
  	e.rxp  = htobe64(rxp);
  	e.txb  = htobe64(txb);
  	e.txp  = htobe64(txp);
  
  	return update_file(path, &e, sizeof(struct traffic_entry));
  }
  
  static int update_radiostat(
  	const char *ifname, uint16_t rate, uint8_t rssi, uint8_t noise
  ) {
  	char path[1024];
  
  	struct stat s;
  	struct radio_entry e;
  
  	snprintf(path, sizeof(path), DB_RD_FILE, ifname);
  
  	if (stat(path, &s))
  	{
  		if (init_file(path, sizeof(struct radio_entry)))
  		{
  			fprintf(stderr, "Failed to init %s: %s\n",
  					path, strerror(errno));
  
  			return -1;
  		}
  	}
  
  	e.time  = htobe32(time(NULL));
  	e.rate  = htobe16(rate);
  	e.rssi  = rssi;
  	e.noise = noise;
  
  	return update_file(path, &e, sizeof(struct radio_entry));
  }
  
  static int update_cnstat(uint32_t udp, uint32_t tcp, uint32_t other)
  {
  	char path[1024];
  
  	struct stat s;
  	struct conn_entry e;
  
  	snprintf(path, sizeof(path), DB_CN_FILE);
  
  	if (stat(path, &s))
  	{
  		if (init_file(path, sizeof(struct conn_entry)))
  		{
  			fprintf(stderr, "Failed to init %s: %s\n",
  					path, strerror(errno));
  
  			return -1;
  		}
  	}
  
  	e.time  = htobe32(time(NULL));
  	e.udp   = htobe32(udp);
  	e.tcp   = htobe32(tcp);
  	e.other = htobe32(other);
  
  	return update_file(path, &e, sizeof(struct conn_entry));
  }
  
  static int update_ldstat(uint16_t load1, uint16_t load5, uint16_t load15)
  {
  	char path[1024];
  
  	struct stat s;
  	struct load_entry e;
  
  	snprintf(path, sizeof(path), DB_LD_FILE);
  
  	if (stat(path, &s))
  	{
  		if (init_file(path, sizeof(struct load_entry)))
  		{
  			fprintf(stderr, "Failed to init %s: %s\n",
  					path, strerror(errno));
  
  			return -1;
  		}
  	}
  
  	e.time   = htobe32(time(NULL));
  	e.load1  = htobe16(load1);
  	e.load5  = htobe16(load5);
  	e.load15 = htobe16(load15);
  
  	return update_file(path, &e, sizeof(struct load_entry));
  }
  
  static int run_daemon(void)
  {
  	DIR *dir;
  	FILE *info;
  	uint64_t rxb, txb, rxp, txp;
  	uint32_t udp, tcp, other;
  	uint16_t rate;
  	uint8_t rssi, noise;
  	float lf1, lf5, lf15;
  	char line[1024];
  	char path[64];
  	char buf[32];
  	int i;
  	void *iw;
  	struct sigaction sa;
  	struct dirent *e;
  
  	struct stat s;
  	const char *ipc = stat("/proc/net/nf_conntrack", &s)
  		? "/proc/net/ip_conntrack" : "/proc/net/nf_conntrack";
  
  	const struct {
  		const char *file;
  		uint64_t *value;
  	} sysfs_stats[] = {
  		{ "rx_packets", &rxp },
  		{ "tx_packets", &txp },
  		{ "rx_bytes",   &rxb },
  		{ "tx_bytes",   &txb }
  	};
  
  	switch (fork())
  	{
  		case -1:
  			perror("fork()");
  			return -1;
  
  		case 0:
  			if (chdir("/") < 0)
  			{
  				perror("chdir()");
  				exit(1);
  			}
  
  			close(0);
  			close(1);
  			close(2);
  			break;
  
  		default:
  			return 0;
  	}
  
  	/* setup USR1 signal handler to reset timer */
  	sa.sa_handler = reset_countdown;
  	sa.sa_flags   = SA_RESTART;
  	sigemptyset(&sa.sa_mask);
  	sigaction(SIGUSR1, &sa, NULL);
  
  	/* write pid */
  	if (writepid())
  	{
  		fprintf(stderr, "Failed to write pid file: %s\n", strerror(errno));
  		return 1;
  	}
  
  	/* initialize iwinfo */
  	iw = iw_open();
  
  	/* go */
  	for (reset_countdown(0); countdown >= 0; countdown--)
  	{
  		/* alter progname for ps, top */
  		memset(progname, 0, prognamelen);
  		snprintf(progname, prognamelen, "luci-bwc %d", countdown);
  
  		dir = opendir("/sys/class/net");
  
  		if (dir)
  		{
  			while ((e = readdir(dir)) != NULL)
  			{
  				if (!strcmp(e->d_name, "lo") || !strcmp(e->d_name, ".") || !strcmp(e->d_name, ".."))
  					continue;
  
  				if (iw && iw_update(iw, e->d_name, &rate, &rssi, &noise))
  					update_radiostat(e->d_name, rate, rssi, noise);
  
  				for (i = 0; i < sizeof(sysfs_stats)/sizeof(sysfs_stats[0]); i++)
  				{
  					*sysfs_stats[i].value = 0;
  
  					snprintf(path, sizeof(path), "/sys/class/net/%s/statistics/%s",
  						e->d_name, sysfs_stats[i].file);
  
  					if ((info = fopen(path, "r")) != NULL)
  					{
  						memset(buf, 0, sizeof(buf));
  						fread(buf, 1, sizeof(buf) - 1, info);
  						fclose(info);
  
  						*sysfs_stats[i].value = (uint64_t)strtoull(buf, NULL, 10);
  					}
  				}
  
  				update_ifstat(e->d_name, rxb, rxp, txb, txp);
  			}
  
  			closedir(dir);
  		}
  
  		if ((info = fopen(ipc, "r")) != NULL)
  		{
  			udp   = 0;
  			tcp   = 0;
  			other = 0;
  
  			while (fgets(line, sizeof(line), info))
  			{
  				if (strstr(line, "TIME_WAIT"))
  					continue;
  
  				if ((strstr(line, "src=127.0.0.1 ") && strstr(line, "dst=127.0.0.1 "))
  				|| (strstr(line, "src=::1 ") && strstr(line, "dst=::1 ")))
  					continue;
  
  				if (sscanf(line, "%*s %*d %s", buf) || sscanf(line, "%s %*d", buf))
  				{
  					if (!strcmp(buf, "tcp"))
  						tcp++;
  					else if (!strcmp(buf, "udp"))
  						udp++;
  					else
  						other++;
  				}
  			}
  
  			update_cnstat(udp, tcp, other);
  
  			fclose(info);
  		}
  
  		if ((info = fopen("/proc/loadavg", "r")) != NULL)
  		{
  			if (fscanf(info, LD_SCAN_PATTERN, &lf1, &lf5, &lf15))
  			{
  				update_ldstat((uint16_t)(lf1  * 100),
  							  (uint16_t)(lf5  * 100),
  							  (uint16_t)(lf15 * 100));
  			}
  
  			fclose(info);
  		}
  
  		sleep(STEP_TIME);
  	}
  
  	unlink(PID_PATH);
  
  	if (iw)
  		iw_close(iw);
  
  	return 0;
  }
  
  static void check_daemon(void)
  {
  	int pid;
  
  	if ((pid = readpid()) < 0 || kill(pid, 0) < 0)
  	{
  		/* daemon ping failed, try to start it up */
  		if (run_daemon())
  		{
  			fprintf(stderr,
  				"Failed to ping daemon and unable to start it up: %s\n",
  				strerror(errno));
  
  			exit(1);
  		}
  	}
  	else if (kill(pid, SIGUSR1))
  	{
  		fprintf(stderr, "Failed to send signal: %s\n", strerror(errno));
  		exit(2);
  	}
  }
  
  static int run_dump_ifname(const char *ifname)
  {
  	int i;
  	char path[1024];
  	struct file_map m;
  	struct traffic_entry *e;
  
  	check_daemon();
  	snprintf(path, sizeof(path), DB_IF_FILE, ifname);
  
  	if (mmap_file(path, sizeof(struct traffic_entry), &m))
  	{
  		fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
  		return 1;
  	}
  
  	for (i = 0; i < m.size; i += sizeof(struct traffic_entry))
  	{
  		e = (struct traffic_entry *) &m.mmap[i];
  
  		if (!e->time)
  			continue;
  
  		printf("[ %" PRIu32 ", %" PRIu64 ", %" PRIu64
  			   ", %" PRIu64 ", %" PRIu64 " ]%s\n",
  			be32toh(e->time),
  			be64toh(e->rxb), be64toh(e->rxp),
  			be64toh(e->txb), be64toh(e->txp),
  			((i + sizeof(struct traffic_entry)) < m.size) ? "," : "");
  	}
  
  	umap_file(&m);
  
  	return 0;
  }
  
  static int run_dump_radio(const char *ifname)
  {
  	int i;
  	char path[1024];
  	struct file_map m;
  	struct radio_entry *e;
  
  	check_daemon();
  	snprintf(path, sizeof(path), DB_RD_FILE, ifname);
  
  	if (mmap_file(path, sizeof(struct radio_entry), &m))
  	{
  		fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
  		return 1;
  	}
  
  	for (i = 0; i < m.size; i += sizeof(struct radio_entry))
  	{
  		e = (struct radio_entry *) &m.mmap[i];
  
  		if (!e->time)
  			continue;
  
  		printf("[ %" PRIu32 ", %" PRIu16 ", %" PRIu8 ", %" PRIu8 " ]%s\n",
  			be32toh(e->time),
  			be16toh(e->rate), e->rssi, e->noise,
  			((i + sizeof(struct radio_entry)) < m.size) ? "," : "");
  	}
  
  	umap_file(&m);
  
  	return 0;
  }
  
  static int run_dump_conns(void)
  {
  	int i;
  	char path[1024];
  	struct file_map m;
  	struct conn_entry *e;
  
  	check_daemon();
  	snprintf(path, sizeof(path), DB_CN_FILE);
  
  	if (mmap_file(path, sizeof(struct conn_entry), &m))
  	{
  		fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
  		return 1;
  	}
  
  	for (i = 0; i < m.size; i += sizeof(struct conn_entry))
  	{
  		e = (struct conn_entry *) &m.mmap[i];
  
  		if (!e->time)
  			continue;
  
  		printf("[ %" PRIu32 ", %" PRIu32 ", %" PRIu32 ", %" PRIu32 " ]%s\n",
  			be32toh(e->time), be32toh(e->udp),
  			be32toh(e->tcp), be32toh(e->other),
  			((i + sizeof(struct conn_entry)) < m.size) ? "," : "");
  	}
  
  	umap_file(&m);
  
  	return 0;
  }
  
  static int run_dump_load(void)
  {
  	int i;
  	char path[1024];
  	struct file_map m;
  	struct load_entry *e;
  
  	check_daemon();
  	snprintf(path, sizeof(path), DB_LD_FILE);
  
  	if (mmap_file(path, sizeof(struct load_entry), &m))
  	{
  		fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
  		return 1;
  	}
  
  	for (i = 0; i < m.size; i += sizeof(struct load_entry))
  	{
  		e = (struct load_entry *) &m.mmap[i];
  
  		if (!e->time)
  			continue;
  
  		printf("[ %" PRIu32 ", %" PRIu16 ", %" PRIu16 ", %" PRIu16 " ]%s\n",
  			be32toh(e->time),
  			be16toh(e->load1), be16toh(e->load5), be16toh(e->load15),
  			((i + sizeof(struct load_entry)) < m.size) ? "," : "");
  	}
  
  	umap_file(&m);
  
  	return 0;
  }
  
  
  int main(int argc, char *argv[])
  {
  	int opt;
  
  	progname = argv[0];
  	prognamelen = -1;
  
  	for (opt = 0; opt < argc; opt++)
  		prognamelen += 1 + strlen(argv[opt]);
  
  	while ((opt = getopt(argc, argv, "t:i:r:cl")) > -1)
  	{
  		switch (opt)
  		{
  			case 't':
  				timeout = atoi(optarg);
  				break;
  
  			case 'i':
  				if (optarg)
  					return run_dump_ifname(optarg);
  				break;
  
  			case 'r':
  				if (optarg)
  					return run_dump_radio(optarg);
  				break;
  
  			case 'c':
  				return run_dump_conns();
  
  			case 'l':
  				return run_dump_load();
  
  			default:
  				break;
  		}
  	}
  
  	fprintf(stderr,
  		"Usage:\n"
  		"	%s [-t timeout] -i ifname\n"
  		"	%s [-t timeout] -r radiodev\n"
  		"	%s [-t timeout] -c\n"
  		"	%s [-t timeout] -l\n",
  			argv[0], argv[0], argv[0], argv[0]
  	);
  
  	return 1;
  }
  