summaryrefslogtreecommitdiff
path: root/applets/busybox.c
blob: 5fec3d5ecb91f54e858fb398272f401a50bfb4bc (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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
/* vi: set sw=4 ts=4: */
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include "busybox.h"

#undef APPLET
#undef APPLET_NOUSAGE
#undef PROTOTYPES
#include "applets.h"

#define bb_need_full_version
#define BB_DECLARE_EXTERN
#include "messages.c"

static int been_there_done_that = 0;
const char *applet_name;

#ifdef BB_FEATURE_INSTALLER
/* 
 * directory table
 *		this should be consistent w/ the enum, busybox.h::Location,
 *		or else...
 */
static char* install_dir[] = {
	"/",
	"/bin",
	"/sbin",
	"/usr/bin",
	"/usr/sbin",
};

/* abstract link() */
typedef int (*__link_f)(const char *, const char *);

/* 
 * Where in the filesystem is this busybox?
 * [return]
 *		malloc'd string w/ full pathname of busybox's location
 *		NULL on failure
 */
static char *busybox_fullpath()
{
	pid_t pid;
	char path[256];
	char proc[256];
	int len;

	pid = getpid();
	sprintf(proc, "/proc/%d/exe", pid);
	len = readlink(proc, path, 256);
	if (len != -1) {
		path[len] = 0;
	} else {
		perror_msg("%s", proc);
		return NULL;
	}
	return strdup(path);
}

/* create (sym)links for each applet */
static void install_links(const char *busybox, int use_symbolic_links)
{
	__link_f Link = link;

	char command[256];
	int i;
	int rc;

	if (use_symbolic_links) 
		Link = symlink;

	for (i = 0; applets[i].name != NULL; i++) {
		sprintf ( command, "%s/%s", 
				install_dir[applets[i].location], applets[i].name);
		rc = Link(busybox, command);

		if (rc) {
			perror_msg("%s", command);
		}
	}
}

#endif /* BB_FEATURE_INSTALLER */

int main(int argc, char **argv)
{
	const char *s;

	for (s = applet_name = argv[0]; *s != '\0';) {
		if (*s++ == '/')
			applet_name = s;
	}

#ifdef BB_SH
	/* Add in a special case hack -- whenever **argv == '-'
	 * (i.e. '-su' or '-sh') always invoke the shell */
	if (**argv == '-' && *(*argv+1)!= '-') {
		exit(((*(shell_main)) (argc, argv)));
	}
#endif

	run_applet_by_name(applet_name, argc, argv);
	error_msg_and_die("applet not found");
}


int busybox_main(int argc, char **argv)
{
	int col = 0, len, i;

#ifdef BB_FEATURE_INSTALLER	
	/* 
	 * This style of argument parsing doesn't scale well 
	 * in the event that busybox starts wanting more --options.
	 * If someone has a cleaner approach, by all means implement it.
	 */
	if (argc > 1 && (strcmp(argv[1], "--install") == 0)) {
		int use_symbolic_links = 0;
		int rc = 0;
		char *busybox;

		/* to use symlinks, or not to use symlinks... */
		if (argc > 2) {
			if ((strcmp(argv[2], "-s") == 0)) { 
				use_symbolic_links = 1; 
			}
		}

		/* link */
		busybox = busybox_fullpath();
		if (busybox) {
			install_links(busybox, use_symbolic_links);
			free(busybox);
		} else {
			rc = 1;
		}
		return rc;
	}
#endif /* BB_FEATURE_INSTALLER */

	argc--;

	/* If we've already been here once, exit now */
	if (been_there_done_that == 1 || argc < 1) {
		const struct BB_applet *a = applets;

		fprintf(stderr, "%s\n\n"
				"Usage: busybox [function] [arguments]...\n"
				"   or: [function] [arguments]...\n\n"
				"\tBusyBox is a multi-call binary that combines many common Unix\n"
				"\tutilities into a single executable.  Most people will create a\n"
				"\tlink to busybox for each function they wish to use, and BusyBox\n"
				"\twill act like whatever it was invoked as.\n" 
				"\nCurrently defined functions:\n", full_version);

		while (a->name != 0) {
			col +=
				fprintf(stderr, "%s%s", ((col == 0) ? "\t" : ", "),
						(a++)->name);
			if (col > 60 && a->name != 0) {
				fprintf(stderr, ",\n");
				col = 0;
			}
		}
		fprintf(stderr, "\n\n");
		exit(-1);
	}

	/* Flag that we've been here already */
	been_there_done_that = 1;
	
	/* Move the command line down a notch */
	len = argv[argc] + strlen(argv[argc]) - argv[1];
	memmove(argv[0], argv[1], len);
	memset(argv[0] + len, 0, argv[1] - argv[0]);

	/* Fix up the argv pointers */
	len = argv[1] - argv[0];
	memmove(argv, argv + 1, sizeof(char *) * (argc + 1));
	for (i = 0; i < argc; i++)
		argv[i] -= len;

	return (main(argc, argv));
}

/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/