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 <stdlib.h>
  14#include <string.h>
  15#include <stdio.h>
  16#include <unistd.h>
  17
  18#undef ARRAY_SIZE
  19#define ARRAY_SIZE(x) ((unsigned)(sizeof(x) / sizeof((x)[0])))
  20
  21#include "../include/autoconf.h"
  22#include "../include/applet_metadata.h"
  23
  24struct bb_applet {
  25        const char *name;
  26        const char *main;
  27        enum bb_install_loc_t install_loc;
  28        enum bb_suid_t need_suid;
  29        /* true if instead of fork(); exec("applet"); waitpid();
  30         * one can do fork(); exit(applet_main(argc,argv)); waitpid(); */
  31        unsigned char noexec;
  32        /* Even nicer */
  33        /* true if instead of fork(); exec("applet"); waitpid();
  34         * one can simply call applet_main(argc,argv); */
  35        unsigned char nofork;
  36};
  37
  38/* Define struct bb_applet applets[] */
  39#include "../include/applets.h"
  40
  41enum { NUM_APPLETS = ARRAY_SIZE(applets) };
  42
  43static int offset[NUM_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
  52int main(int argc, char **argv)
  53{
  54        int i;
  55        int ofs;
  56        unsigned MAX_APPLET_NAME_LEN = 1;
  57
  58        qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);
  59
  60        ofs = 0;
  61        for (i = 0; i < NUM_APPLETS; i++) {
  62                offset[i] = ofs;
  63                ofs += strlen(applets[i].name) + 1;
  64        }
  65        /* We reuse 4 high-order bits of offset array for other purposes,
  66         * so if they are indeed needed, refuse to proceed */
  67        if (ofs > 0xfff)
  68                return 1;
  69        if (!argv[1])
  70                return 1;
  71
  72        i = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, 0666);
  73        if (i < 0)
  74                return 1;
  75        dup2(i, 1);
  76
  77        /* Keep in sync with include/busybox.h! */
  78
  79        printf("/* This is a generated file, don't edit */\n\n");
  80
  81        printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
  82        if (NUM_APPLETS == 1) {
  83                printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
  84                printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].main);
  85        }
  86        printf("\n");
  87
  88        //printf("#ifndef SKIP_definitions\n");
  89        printf("const char applet_names[] ALIGN1 = \"\"\n");
  90        for (i = 0; i < NUM_APPLETS; i++) {
  91                printf("\"%s\" \"\\0\"\n", applets[i].name);
  92                if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
  93                        MAX_APPLET_NAME_LEN = strlen(applets[i].name);
  94        }
  95        printf(";\n\n");
  96
  97        printf("#ifndef SKIP_applet_main\n");
  98        printf("int (*const applet_main[])(int argc, char **argv) = {\n");
  99        for (i = 0; i < NUM_APPLETS; i++) {
 100                printf("%s_main,\n", applets[i].main);
 101        }
 102        printf("};\n");
 103        printf("#endif\n\n");
 104
 105        printf("const uint16_t applet_nameofs[] ALIGN2 = {\n");
 106        for (i = 0; i < NUM_APPLETS; i++) {
 107                printf("0x%04x,\n",
 108                        offset[i]
 109#if ENABLE_FEATURE_PREFER_APPLETS
 110                        + (applets[i].nofork << 12)
 111                        + (applets[i].noexec << 13)
 112#endif
 113#if ENABLE_FEATURE_SUID
 114                        + (applets[i].need_suid << 14) /* 2 bits */
 115#endif
 116                );
 117        }
 118        printf("};\n\n");
 119
 120#if ENABLE_FEATURE_INSTALLER
 121        printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
 122        i = 0;
 123        while (i < NUM_APPLETS) {
 124                int v = applets[i].install_loc; /* 3 bits */
 125                if (++i < NUM_APPLETS)
 126                        v |= applets[i].install_loc << 4; /* 3 bits */
 127                printf("0x%02x,\n", v);
 128                i++;
 129        }
 130        printf("};\n");
 131#endif
 132        //printf("#endif /* SKIP_definitions */\n");
 133        printf("\n");
 134        printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
 135
 136        if (argv[2]) {
 137                char line_old[80];
 138                char line_new[80];
 139                FILE *fp;
 140
 141                line_old[0] = 0;
 142                fp = fopen(argv[2], "r");
 143                if (fp) {
 144                        fgets(line_old, sizeof(line_old), fp);
 145                        fclose(fp);
 146                }
 147                sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
 148                if (strcmp(line_old, line_new) != 0) {
 149                        fp = fopen(argv[2], "w");
 150                        if (!fp)
 151                                return 1;
 152                        fputs(line_new, fp);
 153                }
 154        }
 155
 156        return 0;
 157}
 158