/**
* 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
/**
* 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.
*/
# define t(...) do { if (__VA_ARGS__) goto fail; } while (0)
#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: \
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, 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);
