applets/applet_tables.c

   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
  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
  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
  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 }