summaryrefslogtreecommitdiffstats
path: root/runtime/staprun/staprun.c
blob: 4f78166676f9b6f7216f8f00bfa12eff1953d6f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/* -*- linux-c -*-
 *
 * staprun.c - SystemTap module loader 
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (C) 2005-2007 Red Hat, Inc.
 *
 */

#include "staprun.h"
#include <pwd.h>

extern char *optarg;
extern int optopt;
extern int optind;

int verbose = 0;
int target_pid = 0;
int driver_pid = 0;
unsigned int buffer_size = 0;
char *modname = NULL;
char *modpath = NULL;
#define MAXMODOPTIONS 64
char *modoptions[MAXMODOPTIONS];
char *target_cmd = NULL;
char *outfile_name = NULL;
char *username = NULL;
uid_t cmd_uid;
gid_t cmd_gid;

static void usage(char *prog)
{
	fprintf(stderr, "\n%s [-v] [-c cmd ] [-x pid] [-u user]\n"
                "\t[-b bufsize] [-o FILE] kmod-name [kmod-options]\n", prog);
	fprintf(stderr, "-v  Verbose.\n");
	fprintf(stderr, "-c cmd.  Command \'cmd\' will be run and staprun will exit when it does.\n");
	fprintf(stderr, "   _stp_target will contain the pid for the command.\n");
	fprintf(stderr, "-x pid.  Sets _stp_target to pid.\n");
	fprintf(stderr, "-o FILE. Send output to FILE.\n");
	fprintf(stderr, "-u username. Run commands as username.\n");
	fprintf(stderr, "-b buffer size. The systemtap module will specify a buffer size.\n");
	fprintf(stderr, "   Setting one here will override that value. The value should be\n");
	fprintf(stderr, "   an integer between 1 and 64 which be assumed to be the\n");
	fprintf(stderr, "   buffer size in MB. That value will be per-cpu in bulk mode.\n");
	exit(1);
}

int main(int argc, char **argv)
{
	int c;

	while ((c = getopt(argc, argv, "vb:t:d:c:o:u:x:")) != EOF) {
		switch (c) {
		case 'v':
			verbose = 1;
			break;
		case 'b':
		{
			int size = (unsigned)atoi(optarg);
			if (!size)
				usage(argv[0]);
			if (size > 64) {
				fprintf(stderr, "Maximum buffer size is 64 (MB)\n");
				exit(1);
			}
			buffer_size = size;
			break;
		}
		case 't':
		case 'x':
			target_pid = atoi(optarg);
			break;
		case 'd':
			/* internal option used by stap */
			driver_pid = atoi(optarg);
			break;
		case 'c':
			target_cmd = optarg;
			break;
		case 'o':
			outfile_name = optarg;
			break;
		case 'u':
			username = optarg;
			break;
		default:
			usage(argv[0]);
		}
	}

	if (verbose) {
		if (buffer_size)
			printf ("Using a buffer of %u bytes.\n", buffer_size);
	}

	if (optind < argc) {
		/* Collect both full path and just the trailing module name.  */
		modpath = argv[optind++];
		modname = rindex (modpath, '/');
		if (modname == NULL)
			modname = modpath;
		else
			modname++; /* skip over / */
	}

        if (optind < argc) {
		unsigned start_idx = 4; /* reserve four slots in modoptions[] */
		while (optind < argc && start_idx+1 < MAXMODOPTIONS)
			modoptions[start_idx++] = argv[optind++];
		modoptions[start_idx] = NULL;
	}

	if (!modname) {
		fprintf (stderr, "Need a module to load.\n");
		usage(argv[0]);
	}

	if (username) {
		struct passwd *pw = getpwnam(username);
		if (!pw) {
			fprintf(stderr, "Cannot find user \"%s\".\n", username);
			exit(1);
		}
		cmd_uid = pw->pw_uid;
		cmd_gid = pw->pw_gid;
	} else {
		cmd_uid = getuid();
		cmd_gid = getgid();
	}

	/* now bump the priority */
	setpriority (PRIO_PROCESS, 0, -10);

	if (init_staprun()) {
		fprintf(stderr, "Couldn't initialize staprun. Exiting.\n");
		exit(1);
	}

	if (stp_main_loop()) {
		fprintf(stderr,"Couldn't enter main loop. Exiting.\n");
		exit(1);
	}

	return 0;
}