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