filter.c

   1 /* filter.c: filter framework functions
   2  *
   3  * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
   4  *
   5  * Licensed under GNU General Public License v2
   6  *   (see COPYING for full license text)
   7  */
   8
   9 #include "cgit.h"
  10 #include <sys/types.h>
  11 #include <sys/wait.h>
  12 #include <unistd.h>
  13 #include <string.h>
  14 #include <stdlib.h>
  15
  16 int cgit_open_filter(struct cgit_filter *filter)
  17 {
  18         filter->old_stdout = chk_positive(dup(STDOUT_FILENO),
  19                 "Unable to duplicate STDOUT");
  20         chk_zero(pipe(filter->pipe_fh), "Unable to create pipe to subprocess");
  21         filter->pid = chk_non_negative(fork(), "Unable to create subprocess");
  22         if (filter->pid == 0) {
  23                 close(filter->pipe_fh[1]);
  24                 chk_non_negative(dup2(filter->pipe_fh[0], STDIN_FILENO),
  25                         "Unable to use pipe as STDIN");
  26                 execvp(filter->cmd, filter->argv);
  27                 die_errno("Unable to exec subprocess %s", filter->cmd);
  28         }
  29         close(filter->pipe_fh[0]);
  30         chk_non_negative(dup2(filter->pipe_fh[1], STDOUT_FILENO),
  31                 "Unable to use pipe as STDOUT");
  32         close(filter->pipe_fh[1]);
  33         return 0;
  34 }
  35
  36
  37 int cgit_close_filter(struct cgit_filter *filter)
  38 {
  39         int exit_status;
  40
  41         chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
  42                 "Unable to restore STDOUT");
  43         close(filter->old_stdout);
  44         if (filter->pid < 0)
  45                 return 0;
  46         waitpid(filter->pid, &exit_status, 0);
  47         if (WIFEXITED(exit_status) && !WEXITSTATUS(exit_status))
  48                 return 0;
  49         die("Subprocess %s exited abnormally", filter->cmd);
  50 }
  51
  52 struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
  53 {
  54         struct cgit_filter *f;
  55         int args_size = 0;
  56         int extra_args;
  57
  58         if (!cmd || !cmd[0])
  59                 return NULL;
  60
  61         switch (filtertype) {
  62                 case SOURCE:
  63                 case ABOUT:
  64                         extra_args = 1;
  65                         break;
  66
  67                 case COMMIT:
  68                 default:
  69                         extra_args = 0;
  70                         break;
  71         }
  72
  73         f = xmalloc(sizeof(struct cgit_filter));
  74         memset(f, 0, sizeof(struct cgit_filter));
  75
  76         f->cmd = xstrdup(cmd);
  77         args_size = (2 + extra_args) * sizeof(char *);
  78         f->argv = xmalloc(args_size);
  79         memset(f->argv, 0, args_size);
  80         f->argv[0] = f->cmd;
  81         return f;
  82 }