libbb/procps.c - codeaurora/busybox - Gitiles

 /* vi: set sw=4 ts=4: */
 /*
  * Utility routines.
  *
  * Copyright 1998 by Albert Cahalan; all rights reserved.
  * Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
  * SELinux support: (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */

 #include "libbb.h"


 typedef struct unsigned_to_name_map_t {
 	unsigned id;
 	char name[USERNAME_MAX_SIZE];
 } unsigned_to_name_map_t;

 typedef struct cache_t {
 	unsigned_to_name_map_t *cache;
 	int size;
 } cache_t;

 static cache_t username, groupname;

 static void clear_cache(cache_t *cp)
 {
 	free(cp->cache);
 	cp->cache = NULL;
 	cp->size = 0;
 }
 void clear_username_cache(void)
 {
 	clear_cache(&username);
 	clear_cache(&groupname);
 }

 #if 0 /* more generic, but we don't need that yet */
 /* Returns -N-1 if not found. */
 /* cp->cache[N] is allocated and must be filled in this case */
 static int get_cached(cache_t *cp, unsigned id)
 {
 	int i;
 	for (i = 0; i < cp->size; i++)
 		if (cp->cache[i].id == id)
 			return i;
 	i = cp->size++;
 	cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
 	cp->cache[i++].id = id;
 	return -i;
 }
 #endif

 typedef char* ug_func(char *name, int bufsize, long uid);
 static char* get_cached(cache_t *cp, unsigned id, ug_func* fp)
 {
 	int i;
 	for (i = 0; i < cp->size; i++)
 		if (cp->cache[i].id == id)
 			return cp->cache[i].name;
 	i = cp->size++;
 	cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
 	cp->cache[i].id = id;
 	/* Never fails. Generates numeric string if name isn't found */
 	fp(cp->cache[i].name, sizeof(cp->cache[i].name), id);
 	return cp->cache[i].name;
 }
 const char* get_cached_username(uid_t uid)
 {
 	return get_cached(&username, uid, bb_getpwuid);
 }
 const char* get_cached_groupname(gid_t gid)
 {
 	return get_cached(&groupname, gid, bb_getgrgid);
 }


 #define PROCPS_BUFSIZE 1024

 static int read_to_buf(const char *filename, void *buf)
 {
 	int fd;
 	/* open_read_close() would do two reads, checking for EOF.
 	 * When you have 10000 /proc/$NUM/stat to read, it isn't desirable */
 	ssize_t ret = -1;
 	fd = open(filename, O_RDONLY);
 	if (fd >= 0) {
 		ret = read(fd, buf, PROCPS_BUFSIZE-1);
 		close(fd);
 	}
 	((char *)buf)[ret > 0 ? ret : 0] = '\0';
 	return ret;
 }

 procps_status_t *alloc_procps_scan(int flags)
 {
 	procps_status_t* sp = xzalloc(sizeof(procps_status_t));
 	sp->dir = xopendir("/proc");
 	return sp;
 }

 void free_procps_scan(procps_status_t* sp)
 {
 	closedir(sp->dir);
 	free(sp->argv0);
 	USE_SELINUX(free(sp->context);)
 	free(sp);
 }

 #if ENABLE_FEATURE_FAST_TOP
 /* We cut a lot of corners here for speed */
 static unsigned long fast_strtoul_10(char **endptr)
 {
 	char c;
 	char *str = *endptr;
 	unsigned long n = *str - '0';

 	while ((c = *++str) != ' ')
 		n = n*10 + (c - '0');

 	*endptr = str + 1; /* We skip trailing space! */
 	return n;
 }
 static char *skip_fields(char *str, int count)
 {
 	do {
 		while (*str++ != ' ')
 			continue;
 		/* we found a space char, str points after it */
 	} while (--count);
 	return str;
 }
 #endif

 void BUG_comm_size(void);
 procps_status_t *procps_scan(procps_status_t* sp, int flags)
 {
 	struct dirent *entry;
 	char buf[PROCPS_BUFSIZE];
 	char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
 	char *filename_tail;
 	long tasknice;
 	unsigned pid;
 	int n;
 	struct stat sb;

 	if (!sp)
 		sp = alloc_procps_scan(flags);

 	for (;;) {
 		entry = readdir(sp->dir);
 		if (entry == NULL) {
 			free_procps_scan(sp);
 			return NULL;
 		}
 		pid = bb_strtou(entry->d_name, NULL, 10);
 		if (errno)
 			continue;

 		/* After this point we have to break, not continue
 		 * ("continue" would mean that current /proc/NNN
 		 * is not a valid process info) */

 		memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));

 		sp->pid = pid;
 		if (!(flags & ~PSSCAN_PID)) break;

 #if ENABLE_SELINUX
 		if (flags & PSSCAN_CONTEXT) {
 			if (getpidcon(sp->pid, &sp->context) < 0)
 				sp->context = NULL;
 		}
 #endif

 		filename_tail = filename + sprintf(filename, "/proc/%d", pid);

 		if (flags & PSSCAN_UIDGID) {
 			if (stat(filename, &sb))
 				break;
 			/* Need comment - is this effective or real UID/GID? */
 			sp->uid = sb.st_uid;
 			sp->gid = sb.st_gid;
 		}

 		if (flags & PSSCAN_STAT) {
 			char *cp, *comm1;
 			int tty;
 #if !ENABLE_FEATURE_FAST_TOP
 			unsigned long vsz, rss;
 #endif

 			/* see proc(5) for some details on this */
 			strcpy(filename_tail, "/stat");
 			n = read_to_buf(filename, buf);
 			if (n < 0)
 				break;
 			cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
 			/*if (!cp || cp[1] != ' ')
 				break;*/
 			cp[0] = '\0';
 			if (sizeof(sp->comm) < 16)
 				BUG_comm_size();
 			comm1 = strchr(buf, '(');
 			/*if (comm1)*/
 				safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));

 #if !ENABLE_FEATURE_FAST_TOP
 			n = sscanf(cp+2,
 				"%c %u "               /* state, ppid */
 				"%u %u %d %*s "        /* pgid, sid, tty, tpgid */
 				"%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 				"%lu %lu "             /* utime, stime */
 				"%*s %*s %*s "         /* cutime, cstime, priority */
 				"%ld "                 /* nice */
 				"%*s %*s %*s "         /* timeout, it_real_value, start_time */
 				"%lu "                 /* vsize */
 				"%lu "                 /* rss */
 			/*	"%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
 			/*	"%u %u %u %u "         signal, blocked, sigignore, sigcatch */
 			/*	"%lu %lu %lu"          wchan, nswap, cnswap */
 				,
 				sp->state, &sp->ppid,
 				&sp->pgid, &sp->sid, &tty,
 				&sp->utime, &sp->stime,
 				&tasknice,
 				&vsz,
 				&rss);
 			if (n != 10)
 				break;
 			sp->vsz = vsz >> 10; /* vsize is in bytes and we want kb */
 			sp->rss = rss >> 10;
 			sp->tty_major = (tty >> 8) & 0xfff;
 			sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
 #else
 /* This costs ~100 bytes more but makes top faster by 20%
  * If you run 10000 processes, this may be important for you */
 			sp->state[0] = cp[2];
 			cp += 4;
 			sp->ppid = fast_strtoul_10(&cp);
 			sp->pgid = fast_strtoul_10(&cp);
 			sp->sid = fast_strtoul_10(&cp);
 			tty = fast_strtoul_10(&cp);
 			sp->tty_major = (tty >> 8) & 0xfff;
 			sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
 			cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
 			sp->utime = fast_strtoul_10(&cp);
 			sp->stime = fast_strtoul_10(&cp);
 			cp = skip_fields(cp, 3); /* cutime, cstime, priority */
 			tasknice = fast_strtoul_10(&cp);
 			cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
 			sp->vsz = fast_strtoul_10(&cp) >> 10; /* vsize is in bytes and we want kb */
 			sp->rss = fast_strtoul_10(&cp) >> 10;
 #endif

 			if (sp->vsz == 0 && sp->state[0] != 'Z')
 				sp->state[1] = 'W';
 			else
 				sp->state[1] = ' ';
 			if (tasknice < 0)
 				sp->state[2] = '<';
 			else if (tasknice) /* > 0 */
 				sp->state[2] = 'N';
 			else
 				sp->state[2] = ' ';

 		}

 #if 0 /* PSSCAN_CMD is not used */
 		if (flags & (PSSCAN_CMD|PSSCAN_ARGV0)) {
 			if (sp->argv0) {
 				free(sp->argv0);
 				sp->argv0 = NULL;
 			}
 			if (sp->cmd) {
 				free(sp->cmd);
 				sp->cmd = NULL;
 			}
 			strcpy(filename_tail, "/cmdline");
 			/* TODO: to get rid of size limits, read into malloc buf,
 			 * then realloc it down to real size. */
 			n = read_to_buf(filename, buf);
 			if (n <= 0)
 				break;
 			if (flags & PSSCAN_ARGV0)
 				sp->argv0 = xstrdup(buf);
 			if (flags & PSSCAN_CMD) {
 				do {
 					n--;
 					if ((unsigned char)(buf[n]) < ' ')
 						buf[n] = ' ';
 				} while (n);
 				sp->cmd = xstrdup(buf);
 			}
 		}
 #else
 		if (flags & PSSCAN_ARGV0) {
 			if (sp->argv0) {
 				free(sp->argv0);
 				sp->argv0 = NULL;
 			}
 			strcpy(filename_tail, "/cmdline");
 			n = read_to_buf(filename, buf);
 			if (n <= 0)
 				break;
 			if (flags & PSSCAN_ARGV0)
 				sp->argv0 = xstrdup(buf);
 		}
 #endif
 		break;
 	}
 	return sp;
 }

 void read_cmdline(char *buf, int col, unsigned pid, const char *comm)
 {
 	ssize_t sz;
 	char filename[sizeof("/proc//cmdline") + sizeof(int)*3];

 	sprintf(filename, "/proc/%u/cmdline", pid);
 	sz = open_read_close(filename, buf, col);
 	if (sz > 0) {
 		buf[sz] = '\0';
 		while (--sz >= 0)
 			if ((unsigned char)(buf[sz]) < ' ')
 				buf[sz] = ' ';
 	} else {
 		snprintf(buf, col, "[%s]", comm);
 	}
 }

 /* from kernel:
 	//             pid comm S ppid pgid sid tty_nr tty_pgrp flg
 	sprintf(buffer,"%d (%s) %c %d  %d   %d  %d     %d       %lu %lu \
 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
 %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
 		task->pid,
 		tcomm,
 		state,
 		ppid,
 		pgid,
 		sid,
 		tty_nr,
 		tty_pgrp,
 		task->flags,
 		min_flt,
 		cmin_flt,
 		maj_flt,
 		cmaj_flt,
 		cputime_to_clock_t(utime),
 		cputime_to_clock_t(stime),
 		cputime_to_clock_t(cutime),
 		cputime_to_clock_t(cstime),
 		priority,
 		nice,
 		num_threads,
 		// 0,
 		start_time,
 		vsize,
 		mm ? get_mm_rss(mm) : 0,
 		rsslim,
 		mm ? mm->start_code : 0,
 		mm ? mm->end_code : 0,
 		mm ? mm->start_stack : 0,
 		esp,
 		eip,
 the rest is some obsolete cruft
 */
	/* vi: set sw=4 ts=4: */
	/*
	* Utility routines.
	*
	* Copyright 1998 by Albert Cahalan; all rights reserved.
	* Copyright (C) 2002 by Vladimir Oleynik <dzo@simtreas.ru>
	* SELinux support: (c) 2007 by Yuichi Nakamura <ynakam@hitachisoft.jp>
	*
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/

	#include "libbb.h"


	typedef struct unsigned_to_name_map_t {
	unsigned id;
	char name[USERNAME_MAX_SIZE];
	} unsigned_to_name_map_t;

	typedef struct cache_t {
	unsigned_to_name_map_t *cache;
	int size;
	} cache_t;

	static cache_t username, groupname;

	static void clear_cache(cache_t *cp)
	{
	free(cp->cache);
	cp->cache = NULL;
	cp->size = 0;
	}
	void clear_username_cache(void)
	{
	clear_cache(&username);
	clear_cache(&groupname);
	}

	#if 0 /* more generic, but we don't need that yet */
	/* Returns -N-1 if not found. */
	/* cp->cache[N] is allocated and must be filled in this case */
	static int get_cached(cache_t *cp, unsigned id)
	{
	int i;
	for (i = 0; i < cp->size; i++)
	if (cp->cache[i].id == id)
	return i;
	i = cp->size++;
	cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
	cp->cache[i++].id = id;
	return -i;
	}
	#endif

	typedef char* ug_func(char *name, int bufsize, long uid);
	static char* get_cached(cache_t cp, unsigned id, ug_func fp)
	{
	int i;
	for (i = 0; i < cp->size; i++)
	if (cp->cache[i].id == id)
	return cp->cache[i].name;
	i = cp->size++;
	cp->cache = xrealloc(cp->cache, cp->size * sizeof(*cp->cache));
	cp->cache[i].id = id;
	/* Never fails. Generates numeric string if name isn't found */
	fp(cp->cache[i].name, sizeof(cp->cache[i].name), id);
	return cp->cache[i].name;
	}
	const char* get_cached_username(uid_t uid)
	{
	return get_cached(&username, uid, bb_getpwuid);
	}
	const char* get_cached_groupname(gid_t gid)
	{
	return get_cached(&groupname, gid, bb_getgrgid);
	}


	#define PROCPS_BUFSIZE 1024

	static int read_to_buf(const char filename, void buf)
	{
	int fd;
	/* open_read_close() would do two reads, checking for EOF.
	* When you have 10000 /proc/$NUM/stat to read, it isn't desirable */
	ssize_t ret = -1;
	fd = open(filename, O_RDONLY);
	if (fd >= 0) {
	ret = read(fd, buf, PROCPS_BUFSIZE-1);
	close(fd);
	}
	((char *)buf)[ret > 0 ? ret : 0] = '\0';
	return ret;
	}

	procps_status_t *alloc_procps_scan(int flags)
	{
	procps_status_t* sp = xzalloc(sizeof(procps_status_t));
	sp->dir = xopendir("/proc");
	return sp;
	}

	void free_procps_scan(procps_status_t* sp)
	{
	closedir(sp->dir);
	free(sp->argv0);
	USE_SELINUX(free(sp->context);)
	free(sp);
	}

	#if ENABLE_FEATURE_FAST_TOP
	/* We cut a lot of corners here for speed */
	static unsigned long fast_strtoul_10(char **endptr)
	{
	char c;
	char str = endptr;
	unsigned long n = *str - '0';

	while ((c = *++str) != ' ')
	n = n*10 + (c - '0');

	endptr = str + 1; / We skip trailing space! */
	return n;
	}
	static char skip_fields(char str, int count)
	{
	do {
	while (*str++ != ' ')
	continue;
	/* we found a space char, str points after it */
	} while (--count);
	return str;
	}
	#endif

	void BUG_comm_size(void);
	procps_status_t procps_scan(procps_status_t sp, int flags)
	{
	struct dirent *entry;
	char buf[PROCPS_BUFSIZE];
	char filename[sizeof("/proc//cmdline") + sizeof(int)*3];
	char *filename_tail;
	long tasknice;
	unsigned pid;
	int n;
	struct stat sb;

	if (!sp)
	sp = alloc_procps_scan(flags);

	for (;;) {
	entry = readdir(sp->dir);
	if (entry == NULL) {
	free_procps_scan(sp);
	return NULL;
	}
	pid = bb_strtou(entry->d_name, NULL, 10);
	if (errno)
	continue;

	/* After this point we have to break, not continue
	* ("continue" would mean that current /proc/NNN
	* is not a valid process info) */

	memset(&sp->vsz, 0, sizeof(*sp) - offsetof(procps_status_t, vsz));

	sp->pid = pid;
	if (!(flags & ~PSSCAN_PID)) break;

	#if ENABLE_SELINUX
	if (flags & PSSCAN_CONTEXT) {
	if (getpidcon(sp->pid, &sp->context) < 0)
	sp->context = NULL;
	}
	#endif

	filename_tail = filename + sprintf(filename, "/proc/%d", pid);

	if (flags & PSSCAN_UIDGID) {
	if (stat(filename, &sb))
	break;
	/* Need comment - is this effective or real UID/GID? */
	sp->uid = sb.st_uid;
	sp->gid = sb.st_gid;
	}

	if (flags & PSSCAN_STAT) {
	char cp, comm1;
	int tty;
	#if !ENABLE_FEATURE_FAST_TOP
	unsigned long vsz, rss;
	#endif

	/* see proc(5) for some details on this */
	strcpy(filename_tail, "/stat");
	n = read_to_buf(filename, buf);
	if (n < 0)
	break;
	cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
	/*if (!cp \|\| cp[1] != ' ')
	break;*/
	cp[0] = '\0';
	if (sizeof(sp->comm) < 16)
	BUG_comm_size();
	comm1 = strchr(buf, '(');
	/if (comm1)/
	safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));

	#if !ENABLE_FEATURE_FAST_TOP
	n = sscanf(cp+2,
	"%c %u " /* state, ppid */
	"%u %u %d %s " / pgid, sid, tty, tpgid */
	"%s %s %s %s %s " / flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
	"%lu %lu " /* utime, stime */
	"%s %s %s " / cutime, cstime, priority */
	"%ld " /* nice */
	"%s %s %s " / timeout, it_real_value, start_time */
	"%lu " /* vsize */
	"%lu " /* rss */
	/* "%lu %lu %lu %lu %lu %lu " rss_rlim, start_code, end_code, start_stack, kstk_esp, kstk_eip */
	/* "%u %u %u %u " signal, blocked, sigignore, sigcatch */
	/* "%lu %lu %lu" wchan, nswap, cnswap */
	,
	sp->state, &sp->ppid,
	&sp->pgid, &sp->sid, &tty,
	&sp->utime, &sp->stime,
	&tasknice,
	&vsz,
	&rss);
	if (n != 10)
	break;
	sp->vsz = vsz >> 10; /* vsize is in bytes and we want kb */
	sp->rss = rss >> 10;
	sp->tty_major = (tty >> 8) & 0xfff;
	sp->tty_minor = (tty & 0xff) \| ((tty >> 12) & 0xfff00);
	#else
	/* This costs ~100 bytes more but makes top faster by 20%
	* If you run 10000 processes, this may be important for you */
	sp->state[0] = cp[2];
	cp += 4;
	sp->ppid = fast_strtoul_10(&cp);
	sp->pgid = fast_strtoul_10(&cp);
	sp->sid = fast_strtoul_10(&cp);
	tty = fast_strtoul_10(&cp);
	sp->tty_major = (tty >> 8) & 0xfff;
	sp->tty_minor = (tty & 0xff) \| ((tty >> 12) & 0xfff00);
	cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
	sp->utime = fast_strtoul_10(&cp);
	sp->stime = fast_strtoul_10(&cp);
	cp = skip_fields(cp, 3); /* cutime, cstime, priority */
	tasknice = fast_strtoul_10(&cp);
	cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
	sp->vsz = fast_strtoul_10(&cp) >> 10; /* vsize is in bytes and we want kb */
	sp->rss = fast_strtoul_10(&cp) >> 10;
	#endif

	if (sp->vsz == 0 && sp->state[0] != 'Z')
	sp->state[1] = 'W';
	else
	sp->state[1] = ' ';
	if (tasknice < 0)
	sp->state[2] = '<';
	else if (tasknice) /* > 0 */
	sp->state[2] = 'N';
	else
	sp->state[2] = ' ';

	}

	#if 0 /* PSSCAN_CMD is not used */
	if (flags & (PSSCAN_CMD\|PSSCAN_ARGV0)) {
	if (sp->argv0) {
	free(sp->argv0);
	sp->argv0 = NULL;
	}
	if (sp->cmd) {
	free(sp->cmd);
	sp->cmd = NULL;
	}
	strcpy(filename_tail, "/cmdline");
	/* TODO: to get rid of size limits, read into malloc buf,
	* then realloc it down to real size. */
	n = read_to_buf(filename, buf);
	if (n <= 0)
	break;
	if (flags & PSSCAN_ARGV0)
	sp->argv0 = xstrdup(buf);
	if (flags & PSSCAN_CMD) {
	do {
	n--;
	if ((unsigned char)(buf[n]) < ' ')
	buf[n] = ' ';
	} while (n);
	sp->cmd = xstrdup(buf);
	}
	}
	#else
	if (flags & PSSCAN_ARGV0) {
	if (sp->argv0) {
	free(sp->argv0);
	sp->argv0 = NULL;
	}
	strcpy(filename_tail, "/cmdline");
	n = read_to_buf(filename, buf);
	if (n <= 0)
	break;
	if (flags & PSSCAN_ARGV0)
	sp->argv0 = xstrdup(buf);
	}
	#endif
	break;
	}
	return sp;
	}

	void read_cmdline(char buf, int col, unsigned pid, const char comm)
	{
	ssize_t sz;
	char filename[sizeof("/proc//cmdline") + sizeof(int)*3];

	sprintf(filename, "/proc/%u/cmdline", pid);
	sz = open_read_close(filename, buf, col);
	if (sz > 0) {
	buf[sz] = '\0';
	while (--sz >= 0)
	if ((unsigned char)(buf[sz]) < ' ')
	buf[sz] = ' ';
	} else {
	snprintf(buf, col, "[%s]", comm);
	}
	}

	/* from kernel:
	// pid comm S ppid pgid sid tty_nr tty_pgrp flg
	sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
	%lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
	%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n",
	task->pid,
	tcomm,
	state,
	ppid,
	pgid,
	sid,
	tty_nr,
	tty_pgrp,
	task->flags,
	min_flt,
	cmin_flt,
	maj_flt,
	cmaj_flt,
	cputime_to_clock_t(utime),
	cputime_to_clock_t(stime),
	cputime_to_clock_t(cutime),
	cputime_to_clock_t(cstime),
	priority,
	nice,
	num_threads,
	// 0,
	start_time,
	vsize,
	mm ? get_mm_rss(mm) : 0,
	rsslim,
	mm ? mm->start_code : 0,
	mm ? mm->end_code : 0,
	mm ? mm->start_stack : 0,
	esp,
	eip,
	the rest is some obsolete cruft
	*/