/**
* Copyright © 2015, 2016 Mattias Andrée <maandree@member.fsf.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#ifndef _DEFAULT_SOURCE
# define _DEFAULT_SOURCE
#endif
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#ifndef t
/**
* Go to `fail` if a statement evaluates to non-zero.
*
* @param ... The statement.
*/
# ifndef DEBUG
# define t(...) do { if (__VA_ARGS__) goto fail; } while (0)
# else
# define t(...) do { if ((__VA_ARGS__) ? (failed__ = #__VA_ARGS__) : 0) { (perror)(failed__); goto fail; } } while (0)
static const char *failed__ = NULL;
# define perror(_) ((void)(_))
# endif
#endif
/**
* A queued job.
*/
struct job {
/**
* The job number.
*/
size_t no;
/**
* The number of “argv” elements in `payload`.
*/
int argc;
/**
* The clock in which `ts` is measured.
*/
clockid_t clk;
/**
* The time when the job shall be executed.
*/
struct timespec ts;
/**
* The number of bytes in `payload`.
*/
size_t n;
/**
* “argv” followed by “envp”.
*/
char payload[];
};
/**
* Defines the function `void usage(void)`
* that prints usage information.
*
* @param synopsis:const char* The command's synopsis sans command name.
* `NULL` if there are not arguments.
*/
#define USAGE(synopsis) \
static void \
usage(void) \
{ \
fprintf(stderr, "usage: %s%s%s\n", \
strrchr(argv0, '/') ? (strrchr(argv0, '/') + 1) : argv0, \
synopsis ? " " : "", synopsis ? synopsis : ""); \
exit(2); \
}
/**
* Declares `argv0` and its value to
* a specified string.
*
* @param name:sitrng literal The name of the command.
*/
#define COMMAND(name) \
const char *argv0 = name;
/**
* Print usage and exit if there is any argument
* that is an option.
*/
#define NO_OPTIONS \
do { \
int i; \
if (!strcmp(argv[1], "--")) \
argv++, argc--; \
for (i = 1; i < argc; i++) \
if (strchr("-", argv[i][0])) \
usage(); \
} while (0)
/**
* Construct a message from `argv`
* to send to the daemon.
*/
#define CONSTRUCT_MESSAGE \
n = measure_array(argv + 1); \
t (n ? !(msg = malloc(n)) : 0); \
store_array(msg, argv + 1)
/**
* Send message to daemon.
*
* @param cmd:enum command Command type.
* @param n:size_t The length of the message, 0 if
* `msg` is `NULL` or NUL-terminated.
* @param msg:char * The message to send.
*/
#define SEND(type, n, msg) \
do { \
if (send_command(type, n, msg)) { \
t (errno); \
free(msg); \
return 3; \
} \
} while (0)
/**
* Exit the process with status indicating success.
*
* Defined the label `fail`.
*
* @param msg The message send to the daemon.
*/
#define END(msg) \
free(msg); \
return 0; \
fail: \
perror(argv0); \
free(msg); \
return 1;
/**
* This block of code allows us to compile with DEBUG=valgrind
* or DEBUG=strace and have all exec:s be wrapped in
* valgrind --leak-check=full --show-leak-kinds=all or
* strace, respectively. Very useful for debugging. However,
* children do not inherit strace, so between forking and
* exec:ing we do not have strace.
*/
#if 1 && defined(DEBUG)
# if ((DEBUG == 2) || (DEBUG == 3))
# ifdef __GNUC__
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
__attribute__((__used__))
# endif
# if DEBUG == 2
# define DEBUGPROG "strace"
# else
# define DEBUGPROG "valgrind"
# endif
# define execl(path, _, ...) (execl)("/usr/bin/" DEBUGPROG, "/usr/bin/" DEBUGPROG, path, __VA_ARGS__)
# define execve(...) execve_(__VA_ARGS__)
static int
execve_(const char *path, char *const argv[], char *const envp[])
{
size_t n = 0;
char **new_argv = NULL;
int x = (DEBUG - 2) * 2, saved_errno;
while (argv[n++]);
t (!(new_argv = malloc((n + 1 + (size_t)x) * sizeof(char *))));
new_argv[x] = "--show-leak-kinds=all";
new_argv[1] = "--leak-check=full";
new_argv[0] = "/usr/bin/" DEBUGPROG;
new_argv[1 + x] = path;
memcpy(new_argv + 2 + x, argv + 1, (n - 1) * sizeof(char *));
(execve)(*new_argv, new_argv, envp);
fail:
return saved_errno = errno, free(new_argv), errno = saved_errno, -1;
}
# ifdef __GNUC__
# pragma GCC diagnostic pop
# endif
# endif
#endif
