/**
* Copyright © 2015 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 <stddef.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <assert.h>
#include <sys/socket.h>
/**
* The file descriptor for the socket.
*/
#define SOCK_FILENO 3
/**
* The file descriptor for the state file.
*/
#define STATE_FILENO 4
/**
* The file descriptor for the CLOCK_BOOTTIME timer.
*/
#define BOOT_FILENO 5
/**
* The file descriptor for the CLOCK_REALTIME timer.
*/
#define REAL_FILENO 6
/**
* The file descriptor for the lock file.
*/
#define LOCK_FILENO 7
/**
* Command: queue a job.
*/
#define SAT_QUEUE 0
/**
* Command: remove jobs.
*/
#define SAT_REMOVE 1
/**
* Command: print job queue.
*/
#define SAT_PRINT 2
/**
* Command: run jobs.
*/
#define SAT_RUN 3
#ifndef t
/**
* Go to `fail` if a statement evaluates to non-zero.
*
* @param ... The statement.
*/
# ifdef DEBUG
# define t(...) do { if ((__VA_ARGS__) ? (failed__ = #__VA_ARGS__) : 0) { (perror)(failed__); goto fail; } } while (0)
static const char *failed__ = NULL;
# define perror(_) ((void)(_))
# else
# define t(...) do { if (__VA_ARGS__) goto fail; } while (0)
# endif
#endif
/**
* Macro to put directly after the variable definitions in `main`.
*/
#define DAEMON_PROLOGUE \
int rc = 0; \
assert(argc == 3); \
t (reopen(STATE_FILENO, O_RDWR)) \
/**
* Macro to put before the cleanup code in `main`.
*/
#define DAEMON_CLEANUP_START \
done: \
(void) send_string(SOCK_FILENO, 127, NULL); \
shutdown(SOCK_FILENO, SHUT_WR); \
close(SOCK_FILENO); \
close(STATE_FILENO)
/**
* Macro to put after the cleanup code in `main`.
*/
#define DAEMON_CLEANUP_END \
return rc; \
fail: \
if (send_string(SOCK_FILENO, STDERR_FILENO, argv[0], ": ", strerror(errno), "\n", NULL)) \
perror(argv[0]); \
rc = 1; \
goto done; \
(void) argc
/**
* 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[];
};
/**
* Wrapper for `pread` that reads the required amount of data.
*
* @param fildes See pread(3).
* @param buf See pread(3).
* @param nbyte See pread(3).
* @param offset See pread(3).
* @return See pread(3), only short if the file is shorter.
*/
ssize_t preadn(int fildes, void *buf, size_t nbyte, size_t offset);
/**
* Wrapper for `pwrite` that writes all specified data.
*
* @param fildes See pwrite(3).
* @param buf See pwrite(3).
* @param nbyte See pwrite(3).
* @param offset See pwrite(3).
* @return See pwrite(3).
*/
ssize_t pwriten(int fildes, const void *buf, size_t nbyte, size_t offset);
/**
* Wrapper for `read` that reads all available data.
*
* Sets `errno` to `EBADMSG` on success.
*
* @param fd The file descriptor from which to to read.
* @param buf Output parameter for the data.
* @param n Output parameter for the number of read bytes.
* @return 0 on success, -1 on error.
*
* @throws Any exception specified for read(3).
* @throws Any exception specified for realloc(3).
*/
int readall(int fd, char **buf, size_t *n);
/**
* Unmarshal a `NULL`-terminated string array.
*
* The elements are not actually copied, subpointers
* to `buf` are stored in the returned list.
*
* @param buf The marshalled array. Must end with a NUL byte.
* @param len The length of `buf`.
* @param n Output parameter for the number of elements. May be `NULL`
* @return The list, `NULL` on error.
*
* @throws Any exception specified for realloc(3).
*/
char **restore_array(char *buf, size_t len, size_t *n);
/**
* Create `NULL`-terminate subcopy of an list,
*
* @param list The list.
* @param n The number of elements in the new sublist.
* @return The sublist, `NULL` on error.
*
* @throws Any exception specified for malloc(3).
*/
char **sublist(char *const *list, size_t n);
/**
* Create a new open file descriptor for an already
* existing file descriptor.
*
* @param fd The file descriptor that shall be promoted
* to a new open file descriptor.
* @param oflag See open(3), `O_CREAT` is not allowed.
* @return 0 on success, -1 on error.
*/
int reopen(int fd, int oflag);
/**
* Send a string to a client.
*
* @param sockfd The file descriptor of the socket.
* @param outfd The file descriptor to which the client shall output the message.
* @param ... `NULL`-terminated list of string to concatenate.
* @return 0 on success, -1 on error.
*/
int send_string(int sockfd, int outfd, ...);
/**
* Run a job or a hook.
*
* @param job The job.
* @param hook The hook, `NULL` to run the job.
* @return 0 on success, -1 on error, 1 if the child failed.
*/
int run_job_or_hook(struct job *job, const char *hook);
/**
* Removes (and optionally runs) a job.
*
* @param jobno The job number, `NULL` for any job.
* @param runjob Shall we run the job too? 2 if its time has expired (not forced).
* @return 0 on success, -1 on error.
*
* @throws 0 The job is not in the queue.
*/
int remove_job(const char *jobno, int runjob);
/**
* Get a `NULL`-terminated list of all queued jobs.
*
* @return A `NULL`-terminated list of all queued jobs. `NULL` on error.
*/
struct job **get_jobs(void);
/**
* 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
