cosmopolitan/libc/dns/gethoststxt.c
Justine Tunney 2046c0d2ae Make improvements
- Expand redbean UNIX module
- Expand redbean documentation
- Ensure Lua copyright is embedded in binary
- Increase the PATH_MAX limit especially on NT
- Use column major sorting for linenoise completions
- Fix some suboptimalities in redbean's new UNIX API
- Figured out right flags for Multics newline in raw mode
2022-04-24 10:06:05 -07:00

83 lines
3.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/bits.h"
#include "libc/bits/pushpop.h"
#include "libc/bits/safemacros.internal.h"
#include "libc/calls/calls.h"
#include "libc/dce.h"
#include "libc/dns/hoststxt.h"
#include "libc/fmt/fmt.h"
#include "libc/macros.internal.h"
#include "libc/nt/systeminfo.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
static struct HostsTxt *g_hoststxt;
static struct HostsTxtInitialStaticMemory {
struct HostsTxt ht;
struct HostsTxtEntry entries[8];
char strings[64];
} g_hoststxt_init;
static textwindows dontinline char *GetNtHostsTxtPath(char *pathbuf,
uint32_t size) {
const char *const kWinHostsPath = "\\drivers\\etc\\hosts";
uint32_t len = GetSystemDirectoryA(&pathbuf[0], size);
if (len && len + strlen(kWinHostsPath) + 1 < size) {
if (pathbuf[len] == '\\') pathbuf[len--] = '\0';
memcpy(&pathbuf[len], kWinHostsPath, strlen(kWinHostsPath) + 1);
return &pathbuf[0];
} else {
return NULL;
}
}
/**
* Returns hosts.txt map.
*
* @note yoinking realloc() ensures there's no size limits
*/
const struct HostsTxt *GetHostsTxt(void) {
FILE *f;
const char *path;
char pathbuf[PATH_MAX + 1];
struct HostsTxtInitialStaticMemory *init;
init = &g_hoststxt_init;
if (!g_hoststxt) {
g_hoststxt = &init->ht;
init->ht.entries.n = pushpop(ARRAYLEN(init->entries));
init->ht.entries.p = init->entries;
init->ht.strings.n = pushpop(ARRAYLEN(init->strings));
init->ht.strings.p = init->strings;
__cxa_atexit(FreeHostsTxt, &g_hoststxt, NULL);
path = "/etc/hosts";
if (IsWindows()) {
path = firstnonnull(GetNtHostsTxtPath(pathbuf, ARRAYLEN(pathbuf)), path);
}
if (fileexists(path) && (f = fopen(path, "r"))) {
if (ParseHostsTxt(g_hoststxt, f) == -1) {
/* TODO(jart): Elevate robustness. */
}
fclose(f);
}
}
return g_hoststxt;
}