1 | /* vi: set sw=4 ts=4: */
|
---|
2 | /*
|
---|
3 | * Utility routines.
|
---|
4 | *
|
---|
5 | * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
|
---|
6 | *
|
---|
7 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
---|
8 | */
|
---|
9 |
|
---|
10 | #include "libbb.h"
|
---|
11 |
|
---|
12 | /*
|
---|
13 | In Linux we have three ways to determine "process name":
|
---|
14 | 1. /proc/PID/stat has "...(name)...", among other things. It's so-called "comm" field.
|
---|
15 | 2. /proc/PID/cmdline's first NUL-terminated string. It's argv[0] from exec syscall.
|
---|
16 | 3. /proc/PID/exe symlink. Points to the running executable file.
|
---|
17 |
|
---|
18 | kernel threads:
|
---|
19 | comm: thread name
|
---|
20 | cmdline: empty
|
---|
21 | exe: <readlink fails>
|
---|
22 |
|
---|
23 | executable
|
---|
24 | comm: first 15 chars of base name
|
---|
25 | (if executable is a symlink, then first 15 chars of symlink name are used)
|
---|
26 | cmdline: argv[0] from exec syscall
|
---|
27 | exe: points to executable (resolves symlink, unlike comm)
|
---|
28 |
|
---|
29 | script (an executable with #!/path/to/interpreter):
|
---|
30 | comm: first 15 chars of script's base name (symlinks are not resolved)
|
---|
31 | cmdline: /path/to/interpreter (symlinks are not resolved)
|
---|
32 | (script name is in argv[1], args are pushed into argv[2] etc)
|
---|
33 | exe: points to interpreter's executable (symlinks are resolved)
|
---|
34 |
|
---|
35 | If FEATURE_PREFER_APPLETS=y (and more so if FEATURE_SH_STANDALONE=y),
|
---|
36 | some commands started from busybox shell, xargs or find are started by
|
---|
37 | execXXX("/proc/self/exe", applet_name, params....)
|
---|
38 | and therefore comm field contains "exe".
|
---|
39 | */
|
---|
40 |
|
---|
41 | static int comm_match(procps_status_t *p, const char *procName)
|
---|
42 | {
|
---|
43 | int argv1idx;
|
---|
44 | const char *argv1;
|
---|
45 |
|
---|
46 | if (strncmp(p->comm, procName, 15) != 0)
|
---|
47 | return 0; /* comm does not match */
|
---|
48 |
|
---|
49 | /* In Linux, if comm is 15 chars, it is truncated.
|
---|
50 | * (or maybe the name was exactly 15 chars, but there is
|
---|
51 | * no way to know that) */
|
---|
52 | if (p->comm[14] == '\0')
|
---|
53 | return 1; /* comm is not truncated - matches */
|
---|
54 |
|
---|
55 | /* comm is truncated, but first 15 chars match.
|
---|
56 | * This can be crazily_long_script_name.sh!
|
---|
57 | * The telltale sign is basename(argv[1]) == procName */
|
---|
58 |
|
---|
59 | if (!p->argv0)
|
---|
60 | return 0;
|
---|
61 |
|
---|
62 | argv1idx = strlen(p->argv0) + 1;
|
---|
63 | if (argv1idx >= p->argv_len)
|
---|
64 | return 0;
|
---|
65 | argv1 = p->argv0 + argv1idx;
|
---|
66 |
|
---|
67 | if (strcmp(bb_basename(argv1), procName) != 0)
|
---|
68 | return 0;
|
---|
69 |
|
---|
70 | return 1;
|
---|
71 | }
|
---|
72 |
|
---|
73 | /* This finds the pid of the specified process.
|
---|
74 | * Currently, it's implemented by rummaging through
|
---|
75 | * the proc filesystem.
|
---|
76 | *
|
---|
77 | * Returns a list of all matching PIDs
|
---|
78 | * It is the caller's duty to free the returned pidlist.
|
---|
79 | *
|
---|
80 | * Modified by Vladimir Oleynik for use with libbb/procps.c
|
---|
81 | */
|
---|
82 | pid_t* FAST_FUNC find_pid_by_name(const char *procName)
|
---|
83 | {
|
---|
84 | pid_t* pidList;
|
---|
85 | int i = 0;
|
---|
86 | procps_status_t* p = NULL;
|
---|
87 |
|
---|
88 | pidList = xzalloc(sizeof(*pidList));
|
---|
89 | while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_COMM|PSSCAN_ARGVN|PSSCAN_EXE))) {
|
---|
90 | if (comm_match(p, procName)
|
---|
91 | /* or we require argv0 to match (essential for matching reexeced /proc/self/exe)*/
|
---|
92 | || (p->argv0 && strcmp(bb_basename(p->argv0), procName) == 0)
|
---|
93 | /* or we require /proc/PID/exe link to match */
|
---|
94 | || (p->exe && strcmp(bb_basename(p->exe), procName) == 0)
|
---|
95 | ) {
|
---|
96 | pidList = xrealloc_vector(pidList, 2, i);
|
---|
97 | pidList[i++] = p->pid;
|
---|
98 | }
|
---|
99 | }
|
---|
100 |
|
---|
101 | pidList[i] = 0;
|
---|
102 | return pidList;
|
---|
103 | }
|
---|
104 |
|
---|
105 | pid_t* FAST_FUNC pidlist_reverse(pid_t *pidList)
|
---|
106 | {
|
---|
107 | int i = 0;
|
---|
108 | while (pidList[i])
|
---|
109 | i++;
|
---|
110 | if (--i >= 0) {
|
---|
111 | pid_t k;
|
---|
112 | int j;
|
---|
113 | for (j = 0; i > j; i--, j++) {
|
---|
114 | k = pidList[i];
|
---|
115 | pidList[i] = pidList[j];
|
---|
116 | pidList[j] = k;
|
---|
117 | }
|
---|
118 | }
|
---|
119 | return pidList;
|
---|
120 | }
|
---|