1 /* vi: set sw=4 ts=4: */
2 /*
3  * Applet table generator.
4  * Runs on host and produces include/applet_tables.h
5  *
6  * Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
7  *
8  * Licensed under GPLv2, see file LICENSE in this source tree.
9  */
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <fcntl.h>
13 #include <limits.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <stdio.h>
17 #include <unistd.h>
18 #include <ctype.h>
19 
20 #undef ARRAY_SIZE
21 #define ARRAY_SIZE(x) ((unsigned)(sizeof(x) / sizeof((x)[0])))
22 
23 #ifndef PATH_MAX
24 #define PATH_MAX 1024
25 #endif
26 
27 #include "../include/autoconf.h"
28 #include "../include/applet_metadata.h"
29 
30 struct bb_applet {
31 	const char *name;
32 	const char *main;
33 	enum bb_install_loc_t install_loc;
34 	enum bb_suid_t need_suid;
35 	/* true if instead of fork(); exec("applet"); waitpid();
36 	 * one can do fork(); exit(applet_main(argc,argv)); waitpid(); */
37 	unsigned char noexec;
38 	/* Even nicer */
39 	/* true if instead of fork(); exec("applet"); waitpid();
40 	 * one can simply call applet_main(argc,argv); */
41 	unsigned char nofork;
42 };
43 
44 /* Define struct bb_applet applets[] */
45 #include "../include/applets.h"
46 
47 enum { NUM_APPLETS = ARRAY_SIZE(applets) };
48 
cmp_name(const void * a,const void * b)49 static int cmp_name(const void *a, const void *b)
50 {
51 	const struct bb_applet *aa = a;
52 	const struct bb_applet *bb = b;
53 	return strcmp(aa->name, bb->name);
54 }
55 
str_isalnum_(const char * s)56 static int str_isalnum_(const char *s)
57 {
58 	while (*s) {
59 		if (!isalnum((unsigned char)*s) && *s != '_')
60 			return 0;
61 		s++;
62 	}
63 	return 1;
64 }
65 
main(int argc,char ** argv)66 int main(int argc, char **argv)
67 {
68 	int i, j;
69 	char tmp1[PATH_MAX], tmp2[PATH_MAX];
70 
71 	// In find_applet_by_name(), before linear search, narrow it down
72 	// by looking at N "equidistant" names. With ~350 applets:
73 	// KNOWN_APPNAME_OFFSETS  cycles
74 	//                     0    9057
75 	//                     2    4604 + ~100 bytes of code
76 	//                     4    2407 + 4 bytes
77 	//                     8    1342 + 8 bytes
78 	//                    16     908 + 16 bytes
79 	//                    32     884 + 32 bytes
80 	// With 8, int16_t applet_nameofs[] table has 7 elements.
81 	int KNOWN_APPNAME_OFFSETS = 8;
82 	// With 128 applets we do two linear searches, with 1..7 strcmp's in the first one
83 	// and 1..16 strcmp's in the second. With 256 apps, second search does 1..32 strcmp's.
84 	if (NUM_APPLETS < 128)
85 		KNOWN_APPNAME_OFFSETS = 4;
86 	if (NUM_APPLETS < 32)
87 		KNOWN_APPNAME_OFFSETS = 0;
88 
89 	qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);
90 
91 	for (i = j = 0; i < NUM_APPLETS-1; ++i) {
92 		if (cmp_name(applets+i, applets+i+1) == 0) {
93 			fprintf(stderr, "%s: duplicate applet name '%s'\n", argv[0],
94 					applets[i].name);
95 			j = 1;
96 		}
97 	}
98 
99 	if (j != 0 || !argv[1])
100 		return 1;
101 	snprintf(tmp1, PATH_MAX, "%s.%u.new", argv[1], (int) getpid());
102 	i = open(tmp1, O_WRONLY | O_TRUNC | O_CREAT, 0666);
103 	if (i < 0)
104 		return 1;
105 	dup2(i, 1);
106 
107 	/* Keep in sync with include/busybox.h! */
108 
109 	printf("/* This is a generated file, don't edit */\n\n");
110 
111 	printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
112 	if (NUM_APPLETS == 1) {
113 		printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
114 		printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].main);
115 	}
116 
117 	printf("#define KNOWN_APPNAME_OFFSETS %u\n\n", KNOWN_APPNAME_OFFSETS);
118 	if (KNOWN_APPNAME_OFFSETS > 0) {
119 		int ofs, offset[KNOWN_APPNAME_OFFSETS], index[KNOWN_APPNAME_OFFSETS];
120 		for (i = 0; i < KNOWN_APPNAME_OFFSETS; i++)
121 			index[i] = i * NUM_APPLETS / KNOWN_APPNAME_OFFSETS;
122 		ofs = 0;
123 		for (i = 0; i < NUM_APPLETS; i++) {
124 			for (j = 0; j < KNOWN_APPNAME_OFFSETS; j++)
125 				if (i == index[j])
126 					offset[j] = ofs;
127 			ofs += strlen(applets[i].name) + 1;
128 		}
129 		/* If the list of names is too long refuse to proceed */
130 		if (ofs > 0xffff)
131 			return 1;
132 		printf("const uint16_t applet_nameofs[] ALIGN2 = {\n");
133 		for (i = 1; i < KNOWN_APPNAME_OFFSETS; i++)
134 			printf("%d,\n", offset[i]);
135 		printf("};\n\n");
136 	}
137 
138 	//printf("#ifndef SKIP_definitions\n");
139 	printf("const char applet_names[] ALIGN1 = \"\"\n");
140 	for (i = 0; i < NUM_APPLETS; i++) {
141 		printf("\"%s\" \"\\0\"\n", applets[i].name);
142 //		if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
143 //			MAX_APPLET_NAME_LEN = strlen(applets[i].name);
144 	}
145 	printf(";\n\n");
146 
147 	for (i = 0; i < NUM_APPLETS; i++) {
148 		if (str_isalnum_(applets[i].name))
149 			printf("#define APPLET_NO_%s %d\n", applets[i].name, i);
150 	}
151 	printf("\n");
152 
153 	printf("#ifndef SKIP_applet_main\n");
154 	printf("int (*const applet_main[])(int argc, char **argv) = {\n");
155 	for (i = 0; i < NUM_APPLETS; i++) {
156 		printf("%s_main,\n", applets[i].main);
157 	}
158 	printf("};\n");
159 	printf("#endif\n\n");
160 
161 #if ENABLE_FEATURE_PREFER_APPLETS \
162  || ENABLE_FEATURE_SH_STANDALONE \
163  || ENABLE_FEATURE_SH_NOFORK
164 	printf("const uint8_t applet_flags[] ALIGN1 = {\n");
165 	i = 0;
166 	while (i < NUM_APPLETS) {
167 		int v = applets[i].nofork + (applets[i].noexec << 1);
168 		if (++i < NUM_APPLETS)
169 			v |= (applets[i].nofork + (applets[i].noexec << 1)) << 2;
170 		if (++i < NUM_APPLETS)
171 			v |= (applets[i].nofork + (applets[i].noexec << 1)) << 4;
172 		if (++i < NUM_APPLETS)
173 			v |= (applets[i].nofork + (applets[i].noexec << 1)) << 6;
174 		printf("0x%02x,\n", v);
175 		i++;
176 	}
177 	printf("};\n\n");
178 #endif
179 
180 #if ENABLE_FEATURE_SUID
181 	printf("const uint8_t applet_suid[] ALIGN1 = {\n");
182 	i = 0;
183 	while (i < NUM_APPLETS) {
184 		int v = applets[i].need_suid; /* 2 bits */
185 		if (++i < NUM_APPLETS)
186 			v |= applets[i].need_suid << 2;
187 		if (++i < NUM_APPLETS)
188 			v |= applets[i].need_suid << 4;
189 		if (++i < NUM_APPLETS)
190 			v |= applets[i].need_suid << 6;
191 		printf("0x%02x,\n", v);
192 		i++;
193 	}
194 	printf("};\n\n");
195 #endif
196 
197 #if ENABLE_FEATURE_INSTALLER
198 	printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
199 	i = 0;
200 	while (i < NUM_APPLETS) {
201 		int v = applets[i].install_loc; /* 3 bits */
202 		if (++i < NUM_APPLETS)
203 			v |= applets[i].install_loc << 4; /* 3 bits */
204 		printf("0x%02x,\n", v);
205 		i++;
206 	}
207 	printf("};\n");
208 #endif
209 	//printf("#endif /* SKIP_definitions */\n");
210 
211 //	printf("\n");
212 //	printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
213 
214 	if (argv[2]) {
215 		FILE *fp;
216 		char line_new[80];
217 //		char line_old[80];
218 
219 		sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
220 //		line_old[0] = 0;
221 //		fp = fopen(argv[2], "r");
222 //		if (fp) {
223 //			fgets(line_old, sizeof(line_old), fp);
224 //			fclose(fp);
225 //		}
226 //		if (strcmp(line_old, line_new) != 0) {
227 			snprintf(tmp2, PATH_MAX, "%s.%u.new", argv[2], (int) getpid());
228 			fp = fopen(tmp2, "w");
229 			if (!fp)
230 				return 1;
231 			fputs(line_new, fp);
232 			if (fclose(fp))
233 				return 1;
234 //		}
235 	}
236 
237 	if (fclose(stdout))
238 		return 1;
239 	if (rename(tmp1, argv[1]))
240 		return 1;
241 	if (rename(tmp2, argv[2]))
242 		return 1;
243 	return 0;
244 }
245