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