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        if (!argv[1])
  88                return 1;
  89        snprintf(tmp1, PATH_MAX, "%s.%u.new", argv[1], (int) getpid());
  90        i = open(tmp1, O_WRONLY | O_TRUNC | O_CREAT, 0666);
  91        if (i < 0)
  92                return 1;
  93        dup2(i, 1);
  94
  95        /* Keep in sync with include/busybox.h! */
  96
  97        printf("/* This is a generated file, don't edit */\n\n");
  98
  99        printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
 100        if (NUM_APPLETS == 1) {
 101                printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
 102                printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].main);
 103        }
 104
 105        printf("#define KNOWN_APPNAME_OFFSETS %u\n\n", KNOWN_APPNAME_OFFSETS);
 106        if (KNOWN_APPNAME_OFFSETS > 0) {
 107                int ofs, offset[KNOWN_APPNAME_OFFSETS], index[KNOWN_APPNAME_OFFSETS];
 108                for (i = 0; i < KNOWN_APPNAME_OFFSETS; i++)
 109                        index[i] = i * NUM_APPLETS / KNOWN_APPNAME_OFFSETS;
 110                ofs = 0;
 111                for (i = 0; i < NUM_APPLETS; i++) {
 112                        for (j = 0; j < KNOWN_APPNAME_OFFSETS; j++)
 113                                if (i == index[j])
 114                                        offset[j] = ofs;
 115                        ofs += strlen(applets[i].name) + 1;
 116                }
 117                /* If the list of names is too long refuse to proceed */
 118                if (ofs > 0xffff)
 119                        return 1;
 120                printf("const uint16_t applet_nameofs[] ALIGN2 = {\n");
 121                for (i = 1; i < KNOWN_APPNAME_OFFSETS; i++)
 122                        printf("%d,\n", offset[i]);
 123                printf("};\n\n");
 124        }
 125
 126        //printf("#ifndef SKIP_definitions\n");
 127        printf("const char applet_names[] ALIGN1 = \"\"\n");
 128        for (i = 0; i < NUM_APPLETS; i++) {
 129                printf("\"%s\" \"\\0\"\n", applets[i].name);
 130//              if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
 131//                      MAX_APPLET_NAME_LEN = strlen(applets[i].name);
 132        }
 133        printf(";\n\n");
 134
 135        for (i = 0; i < NUM_APPLETS; i++) {
 136                if (str_isalnum_(applets[i].name))
 137                        printf("#define APPLET_NO_%s %d\n", applets[i].name, i);
 138        }
 139        printf("\n");
 140
 141        printf("#ifndef SKIP_applet_main\n");
 142        printf("int (*const applet_main[])(int argc, char **argv) = {\n");
 143        for (i = 0; i < NUM_APPLETS; i++) {
 144                printf("%s_main,\n", applets[i].main);
 145        }
 146        printf("};\n");
 147        printf("#endif\n\n");
 148
 149#if ENABLE_FEATURE_PREFER_APPLETS \
 150 || ENABLE_FEATURE_SH_STANDALONE \
 151 || ENABLE_FEATURE_SH_NOFORK
 152        printf("const uint8_t applet_flags[] ALIGN1 = {\n");
 153        i = 0;
 154        while (i < NUM_APPLETS) {
 155                int v = applets[i].nofork + (applets[i].noexec << 1);
 156                if (++i < NUM_APPLETS)
 157                        v |= (applets[i].nofork + (applets[i].noexec << 1)) << 2;
 158                if (++i < NUM_APPLETS)
 159                        v |= (applets[i].nofork + (applets[i].noexec << 1)) << 4;
 160                if (++i < NUM_APPLETS)
 161                        v |= (applets[i].nofork + (applets[i].noexec << 1)) << 6;
 162                printf("0x%02x,\n", v);
 163                i++;
 164        }
 165        printf("};\n\n");
 166#endif
 167
 168#if ENABLE_FEATURE_SUID
 169        printf("const uint8_t applet_suid[] ALIGN1 = {\n");
 170        i = 0;
 171        while (i < NUM_APPLETS) {
 172                int v = applets[i].need_suid; /* 2 bits */
 173                if (++i < NUM_APPLETS)
 174                        v |= applets[i].need_suid << 2;
 175                if (++i < NUM_APPLETS)
 176                        v |= applets[i].need_suid << 4;
 177                if (++i < NUM_APPLETS)
 178                        v |= applets[i].need_suid << 6;
 179                printf("0x%02x,\n", v);
 180                i++;
 181        }
 182        printf("};\n\n");
 183#endif
 184
 185#if ENABLE_FEATURE_INSTALLER
 186        printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
 187        i = 0;
 188        while (i < NUM_APPLETS) {
 189                int v = applets[i].install_loc; /* 3 bits */
 190                if (++i < NUM_APPLETS)
 191                        v |= applets[i].install_loc << 4; /* 3 bits */
 192                printf("0x%02x,\n", v);
 193                i++;
 194        }
 195        printf("};\n");
 196#endif
 197        //printf("#endif /* SKIP_definitions */\n");
 198
 199//      printf("\n");
 200//      printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
 201
 202        if (argv[2]) {
 203                FILE *fp;
 204                char line_new[80];
 205//              char line_old[80];
 206
 207                sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
 208//              line_old[0] = 0;
 209//              fp = fopen(argv[2], "r");
 210//              if (fp) {
 211//                      fgets(line_old, sizeof(line_old), fp);
 212//                      fclose(fp);
 213//              }
 214//              if (strcmp(line_old, line_new) != 0) {
 215                        snprintf(tmp2, PATH_MAX, "%s.%u.new", argv[2], (int) getpid());
 216                        fp = fopen(tmp2, "w");
 217                        if (!fp)
 218                                return 1;
 219                        fputs(line_new, fp);
 220                        if (fclose(fp))
 221                                return 1;
 222//              }
 223        }
 224
 225        if (fclose(stdout))
 226                return 1;
 227        if (rename(tmp1, argv[1]))
 228                return 1;
 229        if (rename(tmp2, argv[2]))
 230                return 1;
 231        return 0;
 232}
 233