busybox/applets/applet_tables.c
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   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
  25struct 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
  42enum { NUM_APPLETS = ARRAY_SIZE(applets) };
  43
  44static 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
  51static 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
  61int 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 || ENABLE_FEATURE_SH_STANDALONE \
 148 || ENABLE_FEATURE_SH_NOFORK
 149        printf("const uint8_t applet_flags[] ALIGN1 = {\n");
 150        i = 0;
 151        while (i < NUM_APPLETS) {
 152                int v = applets[i].nofork + (applets[i].noexec << 1);
 153                if (++i < NUM_APPLETS)
 154                        v |= (applets[i].nofork + (applets[i].noexec << 1)) << 2;
 155                if (++i < NUM_APPLETS)
 156                        v |= (applets[i].nofork + (applets[i].noexec << 1)) << 4;
 157                if (++i < NUM_APPLETS)
 158                        v |= (applets[i].nofork + (applets[i].noexec << 1)) << 6;
 159                printf("0x%02x,\n", v);
 160                i++;
 161        }
 162        printf("};\n\n");
 163#endif
 164
 165#if ENABLE_FEATURE_SUID
 166        printf("const uint8_t applet_suid[] ALIGN1 = {\n");
 167        i = 0;
 168        while (i < NUM_APPLETS) {
 169                int v = applets[i].need_suid; /* 2 bits */
 170                if (++i < NUM_APPLETS)
 171                        v |= applets[i].need_suid << 2;
 172                if (++i < NUM_APPLETS)
 173                        v |= applets[i].need_suid << 4;
 174                if (++i < NUM_APPLETS)
 175                        v |= applets[i].need_suid << 6;
 176                printf("0x%02x,\n", v);
 177                i++;
 178        }
 179        printf("};\n\n");
 180#endif
 181
 182#if ENABLE_FEATURE_INSTALLER
 183        printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
 184        i = 0;
 185        while (i < NUM_APPLETS) {
 186                int v = applets[i].install_loc; /* 3 bits */
 187                if (++i < NUM_APPLETS)
 188                        v |= applets[i].install_loc << 4; /* 3 bits */
 189                printf("0x%02x,\n", v);
 190                i++;
 191        }
 192        printf("};\n");
 193#endif
 194        //printf("#endif /* SKIP_definitions */\n");
 195
 196//      printf("\n");
 197//      printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
 198
 199        if (argv[2]) {
 200                FILE *fp;
 201                char line_new[80];
 202//              char line_old[80];
 203
 204                sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
 205//              line_old[0] = 0;
 206//              fp = fopen(argv[2], "r");
 207//              if (fp) {
 208//                      fgets(line_old, sizeof(line_old), fp);
 209//                      fclose(fp);
 210//              }
 211//              if (strcmp(line_old, line_new) != 0) {
 212                        fp = fopen(argv[2], "w");
 213                        if (!fp)
 214                                return 1;
 215                        fputs(line_new, fp);
 216//              }
 217        }
 218
 219        return 0;
 220}
 221