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 tarball for details.
   9 */
  10
  11#include <stdlib.h>
  12#include <string.h>
  13#include <stdio.h>
  14
  15#include "../include/autoconf.h"
  16#include "../include/busybox.h"
  17
  18struct bb_applet {
  19        const char *name;
  20        const char *main;
  21        enum bb_install_loc_t install_loc;
  22        enum bb_suid_t need_suid;
  23        /* true if instead of fork(); exec("applet"); waitpid();
  24         * one can do fork(); exit(applet_main(argc,argv)); waitpid(); */
  25        unsigned char noexec;
  26        /* Even nicer */
  27        /* true if instead of fork(); exec("applet"); waitpid();
  28         * one can simply call applet_main(argc,argv); */
  29        unsigned char nofork;
  30};
  31
  32/* Define struct bb_applet applets[] */
  33#include "../include/applets.h"
  34
  35enum { NUM_APPLETS = ARRAY_SIZE(applets) };
  36
  37static int offset[NUM_APPLETS];
  38
  39static int cmp_name(const void *a, const void *b)
  40{
  41        const struct bb_applet *aa = a;
  42        const struct bb_applet *bb = b;
  43        return strcmp(aa->name, bb->name);
  44}
  45
  46int main(int argc, char **argv)
  47{
  48        int i;
  49        int ofs;
  50        unsigned MAX_APPLET_NAME_LEN = 1;
  51
  52        qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);
  53
  54        ofs = 0;
  55        for (i = 0; i < NUM_APPLETS; i++) {
  56                offset[i] = ofs;
  57                ofs += strlen(applets[i].name) + 1;
  58        }
  59        /* We reuse 4 high-order bits of offset array for other purposes,
  60         * so if they are indeed needed, refuse to proceed */
  61        if (ofs > 0xfff)
  62                return 1;
  63        if (!argv[1])
  64                return 1;
  65
  66        i = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, 0666);
  67        if (i < 0)
  68                return 1;
  69        dup2(i, 1);
  70
  71        /* Keep in sync with include/busybox.h! */
  72
  73        printf("/* This is a generated file, don't edit */\n\n");
  74
  75        printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
  76        if (NUM_APPLETS == 1) {
  77                printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
  78                printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].name);
  79        }
  80        printf("\n");
  81
  82        //printf("#ifndef SKIP_definitions\n");
  83        printf("const char applet_names[] ALIGN1 = \"\"\n");
  84        for (i = 0; i < NUM_APPLETS; i++) {
  85                printf("\"%s\" \"\\0\"\n", applets[i].name);
  86                if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
  87                        MAX_APPLET_NAME_LEN = strlen(applets[i].name);
  88        }
  89        printf(";\n\n");
  90
  91        printf("#ifndef SKIP_applet_main\n");
  92        printf("int (*const applet_main[])(int argc, char **argv) = {\n");
  93        for (i = 0; i < NUM_APPLETS; i++) {
  94                printf("%s_main,\n", applets[i].main);
  95        }
  96        printf("};\n");
  97        printf("#endif\n\n");
  98
  99        printf("const uint16_t applet_nameofs[] ALIGN2 = {\n");
 100        for (i = 0; i < NUM_APPLETS; i++) {
 101                printf("0x%04x,\n",
 102                        offset[i]
 103#if ENABLE_FEATURE_PREFER_APPLETS
 104                        + (applets[i].nofork << 12)
 105                        + (applets[i].noexec << 13)
 106#endif
 107#if ENABLE_FEATURE_SUID
 108                        + (applets[i].need_suid << 14) /* 2 bits */
 109#endif
 110                );
 111        }
 112        printf("};\n\n");
 113
 114#if ENABLE_FEATURE_INSTALLER
 115        printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
 116        i = 0;
 117        while (i < NUM_APPLETS) {
 118                int v = applets[i].install_loc; /* 3 bits */
 119                if (++i < NUM_APPLETS)
 120                        v |= applets[i].install_loc << 4; /* 3 bits */
 121                printf("0x%02x,\n", v);
 122                i++;
 123        }
 124        printf("};\n");
 125#endif
 126        //printf("#endif /* SKIP_definitions */\n");
 127        printf("\n");
 128        printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
 129
 130        if (argv[2]) {
 131                char line_old[80];
 132                char line_new[80];
 133                FILE *fp;
 134
 135                line_old[0] = 0;
 136                fp = fopen(argv[2], "r");
 137                if (fp) {
 138                        fgets(line_old, sizeof(line_old), fp);
 139                        fclose(fp);
 140                }
 141                sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
 142                if (strcmp(line_old, line_new) != 0) {
 143                        fp = fopen(argv[2], "w");
 144                        if (!fp)
 145                                return 1;
 146                        fputs(line_new, fp);
 147                }
 148        }
 149
 150        return 0;
 151}
 152