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 
17 #include <limits.h>
18 #include <stdlib.h>
19 #include <unistd.h>
20 #include <string.h>
21 #include <stdio.h>
22 
23 #include "got_compat.h"
24 
25 #include "got_opentemp.h"
26 #include "got_error.h"
27 
28 int
29 got_opentempfd(void)
30 {
31 	char name[PATH_MAX];
32 	int fd;
33 
34 	if (strlcpy(name, GOT_TMPDIR_STR "/got.XXXXXXXX", sizeof(name))
35 	    >= sizeof(name))
36 		return -1;
37 
38 	fd = mkstemp(name);
39 	if (fd != -1)
40 		unlink(name);
41 	return fd;
42 }
43 
44 FILE *
45 got_opentemp(void)
46 {
47 	int fd;
48 	FILE *f;
49 
50 	fd = got_opentempfd();
51 	if (fd < 0)
52 		return NULL;
53 
54 	f = fdopen(fd, "w+");
55 	if (f == NULL) {
56 		close(fd);
57 		return NULL;
58 	}
59 
60 	return f;
61 }
62 
63 const struct got_error *
64 got_opentemp_named(char **path, FILE **outfile, const char *basepath)
65 {
66 	const struct got_error *err = NULL;
67 	int fd;
68 
69 	*outfile = NULL;
70 
71 	if (asprintf(path, "%s-XXXXXX", basepath) == -1) {
72 		*path = NULL;
73 		return got_error_from_errno("asprintf");
74 	}
75 
76 	fd = mkstemp(*path);
77 	if (fd == -1) {
78 		err = got_error_from_errno2("mkstemp", *path);
79 		free(*path);
80 		*path = NULL;
81 		return err;
82 	}
83 
84 	*outfile = fdopen(fd, "w+");
85 	if (*outfile == NULL) {
86 		err = got_error_from_errno2("fdopen", *path);
87 		free(*path);
88 		*path = NULL;
89 	}
90 
91 	return err;
92 }
93 
94 const struct got_error *
95 got_opentemp_named_fd(char **path, int *outfd, const char *basepath)
96 {
97 	const struct got_error *err = NULL;
98 	int fd;
99 
100 	*outfd = -1;
101 
102 	if (asprintf(path, "%s-XXXXXX", basepath) == -1) {
103 		*path = NULL;
104 		return got_error_from_errno("asprintf");
105 	}
106 
107 	fd = mkstemp(*path);
108 	if (fd == -1) {
109 		err = got_error_from_errno("mkstemp");
110 		free(*path);
111 		*path = NULL;
112 		return err;
113 	}
114 
115 	*outfd = fd;
116 	return err;
117 }
118 
119 const struct got_error *
120 got_opentemp_truncate(FILE *f)
121 {
122 	if (fpurge(f) == EOF)
123 		return got_error_from_errno("fpurge");
124 	if (ftruncate(fileno(f), 0L) == -1)
125 		return got_error_from_errno("ftruncate");
126 	if (fseeko(f, 0L, SEEK_SET) == -1)
127 		return got_error_from_errno("fseeko");
128 	return NULL;
129 }