lib/opentemp.c

   1 /*
   2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 #include "got_compat.h"
  17
  18 #include <limits.h>
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <string.h>
  22 #include <stdio.h>
  23
  24 #include "got_opentemp.h"
  25 #include "got_error.h"
  26
  27 int
  28 got_opentempfd(void)
  29 {
  30         char name[PATH_MAX];
  31         int fd;
  32
  33         if (strlcpy(name, GOT_TMPDIR_STR "/got.XXXXXXXXXX", sizeof(name))
  34             >= sizeof(name))
  35                 return -1;
  36
  37         fd = mkstemp(name);
  38         if (fd != -1) {
  39                 if (unlink(name) == -1) {
  40                         close(fd);
  41                         return -1;
  42                 }
  43         }
  44         return fd;
  45 }
  46
  47 FILE *
  48 got_opentemp(void)
  49 {
  50         int fd;
  51         FILE *f;
  52
  53         fd = got_opentempfd();
  54         if (fd < 0)
  55                 return NULL;
  56
  57         f = fdopen(fd, "w+");
  58         if (f == NULL) {
  59                 close(fd);
  60                 return NULL;
  61         }
  62
  63         return f;
  64 }
  65
  66 const struct got_error *
  67 got_opentemp_named(char **path, FILE **outfile, const char *basepath,
  68     const char *suffix)
  69 {
  70         const struct got_error *err = NULL;
  71         int fd;
  72
  73         *outfile = NULL;
  74
  75         if (asprintf(path, "%s-XXXXXXXXXX%s", basepath, suffix) == -1) {
  76                 *path = NULL;
  77                 return got_error_from_errno("asprintf");
  78         }
  79
  80         fd = mkstemps(*path, strlen(suffix));
  81         if (fd == -1) {
  82                 err = got_error_from_errno2("mkstemps", *path);
  83                 free(*path);
  84                 *path = NULL;
  85                 return err;
  86         }
  87
  88         *outfile = fdopen(fd, "w+");
  89         if (*outfile == NULL) {
  90                 err = got_error_from_errno2("fdopen", *path);
  91                 close(fd);
  92                 free(*path);
  93                 *path = NULL;
  94         }
  95
  96         return err;
  97 }
  98
  99 const struct got_error *
 100 got_opentemp_named_fd(char **path, int *outfd, const char *basepath,
 101     const char *suffix)
 102 {
 103         const struct got_error *err = NULL;
 104         int fd;
 105
 106         *outfd = -1;
 107
 108         if (asprintf(path, "%s-XXXXXXXXXX%s", basepath, suffix) == -1) {
 109                 *path = NULL;
 110                 return got_error_from_errno("asprintf");
 111         }
 112
 113         fd = mkstemps(*path, strlen(suffix));
 114         if (fd == -1) {
 115                 err = got_error_from_errno2("mkstemps", *path);
 116                 free(*path);
 117                 *path = NULL;
 118                 return err;
 119         }
 120
 121         *outfd = fd;
 122         return err;
 123 }
 124
 125 const struct got_error *
 126 got_opentemp_truncate(FILE *f)
 127 {
 128         if (fpurge(f) == EOF)
 129                 return got_error_from_errno("fpurge");
 130         if (ftruncate(fileno(f), 0L) == -1)
 131                 return got_error_from_errno("ftruncate");
 132         if (fseeko(f, 0L, SEEK_SET) == -1)
 133                 return got_error_from_errno("fseeko");
 134         return NULL;
 135 }
 136
 137 const struct got_error *
 138 got_opentemp_truncatefd(int fd)
 139 {
 140         if (ftruncate(fd, 0L) == -1)
 141                 return got_error_from_errno("ftruncate");
 142         if (lseek(fd, 0L, SEEK_SET) == -1)
 143                 return got_error_from_errno("lseek");
 144         return NULL;
 145 }