hush/applets/applet_tables.c
Denys Vlasenko 0fb0045aa9 config: disentangle PREFER_APPLETS from SH_STANDALONE and SH_NOFORK
On user request.
I thought enabling/disabling them all together is more consistent.
Evidently, some people do want them to be separately selectable.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-07-22 18:48:38 +02:00

220 lines
5.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Applet table generator.
* Runs on host and produces include/applet_tables.h
*
* Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <ctype.h>
#undef ARRAY_SIZE
#define ARRAY_SIZE(x) ((unsigned)(sizeof(x) / sizeof((x)[0])))
#include "../include/autoconf.h"
#include "../include/applet_metadata.h"
struct bb_applet {
const char *name;
const char *main;
enum bb_install_loc_t install_loc;
enum bb_suid_t need_suid;
/* true if instead of fork(); exec("applet"); waitpid();
* one can do fork(); exit(applet_main(argc,argv)); waitpid(); */
unsigned char noexec;
/* Even nicer */
/* true if instead of fork(); exec("applet"); waitpid();
* one can simply call applet_main(argc,argv); */
unsigned char nofork;
};
/* Define struct bb_applet applets[] */
#include "../include/applets.h"
enum { NUM_APPLETS = ARRAY_SIZE(applets) };
static int cmp_name(const void *a, const void *b)
{
const struct bb_applet *aa = a;
const struct bb_applet *bb = b;
return strcmp(aa->name, bb->name);
}
static int str_isalnum_(const char *s)
{
while (*s) {
if (!isalnum(*s) && *s != '_')
return 0;
s++;
}
return 1;
}
int main(int argc, char **argv)
{
int i, j;
// In find_applet_by_name(), before linear search, narrow it down
// by looking at N "equidistant" names. With ~350 applets:
// KNOWN_APPNAME_OFFSETS cycles
// 0 9057
// 2 4604 + ~100 bytes of code
// 4 2407 + 4 bytes
// 8 1342 + 8 bytes
// 16 908 + 16 bytes
// 32 884 + 32 bytes
// With 8, int16_t applet_nameofs[] table has 7 elements.
int KNOWN_APPNAME_OFFSETS = 8;
// With 128 applets we do two linear searches, with 1..7 strcmp's in the first one
// and 1..16 strcmp's in the second. With 256 apps, second search does 1..32 strcmp's.
if (NUM_APPLETS < 128)
KNOWN_APPNAME_OFFSETS = 4;
if (NUM_APPLETS < 32)
KNOWN_APPNAME_OFFSETS = 0;
qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);
if (!argv[1])
return 1;
i = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, 0666);
if (i < 0)
return 1;
dup2(i, 1);
/* Keep in sync with include/busybox.h! */
printf("/* This is a generated file, don't edit */\n\n");
printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
if (NUM_APPLETS == 1) {
printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].main);
}
printf("#define KNOWN_APPNAME_OFFSETS %u\n\n", KNOWN_APPNAME_OFFSETS);
if (KNOWN_APPNAME_OFFSETS > 0) {
int ofs, offset[KNOWN_APPNAME_OFFSETS], index[KNOWN_APPNAME_OFFSETS];
for (i = 0; i < KNOWN_APPNAME_OFFSETS; i++)
index[i] = i * NUM_APPLETS / KNOWN_APPNAME_OFFSETS;
ofs = 0;
for (i = 0; i < NUM_APPLETS; i++) {
for (j = 0; j < KNOWN_APPNAME_OFFSETS; j++)
if (i == index[j])
offset[j] = ofs;
ofs += strlen(applets[i].name) + 1;
}
/* If the list of names is too long refuse to proceed */
if (ofs > 0xffff)
return 1;
printf("const uint16_t applet_nameofs[] ALIGN2 = {\n");
for (i = 1; i < KNOWN_APPNAME_OFFSETS; i++)
printf("%d,\n", offset[i]);
printf("};\n\n");
}
//printf("#ifndef SKIP_definitions\n");
printf("const char applet_names[] ALIGN1 = \"\"\n");
for (i = 0; i < NUM_APPLETS; i++) {
printf("\"%s\" \"\\0\"\n", applets[i].name);
// if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
// MAX_APPLET_NAME_LEN = strlen(applets[i].name);
}
printf(";\n\n");
for (i = 0; i < NUM_APPLETS; i++) {
if (str_isalnum_(applets[i].name))
printf("#define APPLET_NO_%s %d\n", applets[i].name, i);
}
printf("\n");
printf("#ifndef SKIP_applet_main\n");
printf("int (*const applet_main[])(int argc, char **argv) = {\n");
for (i = 0; i < NUM_APPLETS; i++) {
printf("%s_main,\n", applets[i].main);
}
printf("};\n");
printf("#endif\n\n");
#if ENABLE_FEATURE_PREFER_APPLETS \
|| ENABLE_FEATURE_SH_STANDALONE \
|| ENABLE_FEATURE_SH_NOFORK
printf("const uint8_t applet_flags[] ALIGN1 = {\n");
i = 0;
while (i < NUM_APPLETS) {
int v = applets[i].nofork + (applets[i].noexec << 1);
if (++i < NUM_APPLETS)
v |= (applets[i].nofork + (applets[i].noexec << 1)) << 2;
if (++i < NUM_APPLETS)
v |= (applets[i].nofork + (applets[i].noexec << 1)) << 4;
if (++i < NUM_APPLETS)
v |= (applets[i].nofork + (applets[i].noexec << 1)) << 6;
printf("0x%02x,\n", v);
i++;
}
printf("};\n\n");
#endif
#if ENABLE_FEATURE_SUID
printf("const uint8_t applet_suid[] ALIGN1 = {\n");
i = 0;
while (i < NUM_APPLETS) {
int v = applets[i].need_suid; /* 2 bits */
if (++i < NUM_APPLETS)
v |= applets[i].need_suid << 2;
if (++i < NUM_APPLETS)
v |= applets[i].need_suid << 4;
if (++i < NUM_APPLETS)
v |= applets[i].need_suid << 6;
printf("0x%02x,\n", v);
i++;
}
printf("};\n\n");
#endif
#if ENABLE_FEATURE_INSTALLER
printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
i = 0;
while (i < NUM_APPLETS) {
int v = applets[i].install_loc; /* 3 bits */
if (++i < NUM_APPLETS)
v |= applets[i].install_loc << 4; /* 3 bits */
printf("0x%02x,\n", v);
i++;
}
printf("};\n");
#endif
//printf("#endif /* SKIP_definitions */\n");
// printf("\n");
// printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);
if (argv[2]) {
char line_old[80];
char line_new[80];
FILE *fp;
line_old[0] = 0;
fp = fopen(argv[2], "r");
if (fp) {
fgets(line_old, sizeof(line_old), fp);
fclose(fp);
}
sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
if (strcmp(line_old, line_new) != 0) {
fp = fopen(argv[2], "w");
if (!fp)
return 1;
fputs(line_new, fp);
}
}
return 0;
}