LXR busybox/applets/applet

   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
  30struct 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
  47enum { NUM_APPLETS = ARRAY_SIZE(applets) };
  48
  49static 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
  56static 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
  66int 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