mirror of
https://github.com/FeralInteractive/gamemode.git
synced 2025-06-06 15:47:20 +02:00
97 lines
3.0 KiB
C
97 lines
3.0 KiB
C
/*
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Copyright (c) 2017-2019, Feral Interactive
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of Feral Interactive nor the names of its contributors
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may be used to endorse or promote products derived from this software
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without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#define _GNU_SOURCE
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#include "gamemode.h"
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#include <fcntl.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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/**
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* Lookup the process environment for a specific variable or return NULL.
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* Requires an open directory FD from /proc/PID.
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*/
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char *game_mode_lookup_proc_env(const procfd_t proc_fd, const char *var)
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{
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char *environ = NULL;
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int fd = openat(proc_fd, "environ", O_RDONLY | O_CLOEXEC);
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if (fd != -1) {
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FILE *stream = fdopen(fd, "r");
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if (stream) {
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/* Read every \0 terminated line from the environment */
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char *line = NULL;
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size_t len = 0;
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size_t pos = strlen(var) + 1;
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while (!environ && (getdelim(&line, &len, 0, stream) != -1)) {
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/* Find a match including the "=" suffix */
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if ((len > pos) && (strncmp(line, var, strlen(var)) == 0) && (line[pos - 1] == '='))
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environ = strndup(line + pos, len - pos);
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}
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free(line);
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fclose(stream);
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} else
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close(fd);
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}
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/* If found variable is empty, skip it */
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if (environ && !strlen(environ)) {
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free(environ);
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environ = NULL;
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}
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return environ;
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}
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/**
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* Lookup the home directory of the user in a safe way.
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*/
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char *game_mode_lookup_user_home(void)
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{
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/* Try loading env HOME first */
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const char *home = secure_getenv("HOME");
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if (!home) {
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/* If HOME is not defined (or out of context), fall back to passwd */
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struct passwd *pw = getpwuid(getuid());
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if (!pw)
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return NULL;
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home = pw->pw_dir;
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}
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/* Try to allocate into our heap */
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return home ? strdup(home) : NULL;
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}
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