93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Utility routines.
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*
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* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
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*
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* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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*/
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#include "libbb.h"
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/*
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In Linux we have three ways to determine "process name":
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1. /proc/PID/stat has "...(name)...", among other things. It's so-called "comm" field.
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2. /proc/PID/cmdline's first NUL-terminated string. It's argv[0] from exec syscall.
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3. /proc/PID/exe symlink. Points to the running executable file.
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kernel threads:
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comm: thread name
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cmdline: empty
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exe: <readlink fails>
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executable
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comm: first 15 chars of base name
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(if executable is a symlink, then first 15 chars of symlink name are used)
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cmdline: argv[0] from exec syscall
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exe: points to executable (resolves symlink, unlike comm)
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script (an executable with #!/path/to/interpreter):
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comm: first 15 chars of script's base name (symlinks are not resolved)
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cmdline: /path/to/interpreter (symlinks are not resolved)
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(script name is in argv[1], args are pushed into argv[2] etc)
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exe: points to interpreter's executable (symlinks are resolved)
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If FEATURE_PREFER_APPLETS=y (and more so if FEATURE_SH_STANDALONE=y),
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some commands started from busybox shell, xargs or find are started by
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execXXX("/proc/self/exe", applet_name, params....)
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and therefore comm field contains "exe".
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*/
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/* find_pid_by_name()
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*
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* Modified by Vladimir Oleynik for use with libbb/procps.c
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* This finds the pid of the specified process.
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* Currently, it's implemented by rummaging through
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* the proc filesystem.
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*
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* Returns a list of all matching PIDs
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* It is the caller's duty to free the returned pidlist.
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*/
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pid_t* find_pid_by_name(const char* procName)
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{
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pid_t* pidList;
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int i = 0;
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procps_status_t* p = NULL;
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pidList = xmalloc(sizeof(*pidList));
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while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_COMM|PSSCAN_ARGV0))) {
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if (
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/* we require comm to match and to not be truncated */
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/* in Linux, if comm is 15 chars, it may be a truncated
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* name, so we don't allow that to match */
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(!p->comm[sizeof(p->comm)-2] && strcmp(p->comm, procName) == 0)
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/* or we require argv0 to match (essential for matching reexeced /proc/self/exe)*/
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|| (p->argv0 && strcmp(bb_basename(p->argv0), procName) == 0)
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/* TOOD: we can also try /proc/NUM/exe link, do we want that? */
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) {
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pidList = xrealloc(pidList, sizeof(*pidList) * (i+2));
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pidList[i++] = p->pid;
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}
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}
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pidList[i] = 0;
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return pidList;
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}
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pid_t *pidlist_reverse(pid_t *pidList)
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{
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int i = 0;
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while (pidList[i])
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i++;
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if (--i >= 0) {
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pid_t k;
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int j;
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for (j = 0; i > j; i--, j++) {
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k = pidList[i];
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pidList[i] = pidList[j];
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pidList[j] = k;
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}
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}
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return pidList;
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}
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