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_opentemp.h"
24 #include "got_error.h"
25 
26 int
27 got_opentempfd(void)
28 {
29 	char name[PATH_MAX];
30 	int fd;
31 
32 	if (strlcpy(name, GOT_TMPDIR_STR "/got.XXXXXXXX", sizeof(name))
33 	    >= sizeof(name))
34 		return -1;
35 
36 	fd = mkstemp(name);
37 	if (fd != -1) {
38 		if (unlink(name) == -1) {
39 			close(fd);
40 			return -1;
41 		}
42 	}
43 	return fd;
44 }
45 
46 FILE *
47 got_opentemp(void)
48 {
49 	int fd;
50 	FILE *f;
51 
52 	fd = got_opentempfd();
53 	if (fd < 0)
54 		return NULL;
55 
56 	f = fdopen(fd, "w+");
57 	if (f == NULL) {
58 		close(fd);
59 		return NULL;
60 	}
61 
62 	return f;
63 }
64 
65 const struct got_error *
66 got_opentemp_named(char **path, FILE **outfile, const char *basepath)
67 {
68 	const struct got_error *err = NULL;
69 	int fd;
70 
71 	*outfile = NULL;
72 
73 	if (asprintf(path, "%s-XXXXXX", basepath) == -1) {
74 		*path = NULL;
75 		return got_error_from_errno("asprintf");
76 	}
77 
78 	fd = mkstemp(*path);
79 	if (fd == -1) {
80 		err = got_error_from_errno2("mkstemp", *path);
81 		free(*path);
82 		*path = NULL;
83 		return err;
84 	}
85 
86 	*outfile = fdopen(fd, "w+");
87 	if (*outfile == NULL) {
88 		err = got_error_from_errno2("fdopen", *path);
89 		free(*path);
90 		*path = NULL;
91 	}
92 
93 	return err;
94 }
95 
96 const struct got_error *
97 got_opentemp_named_fd(char **path, int *outfd, const char *basepath)
98 {
99 	const struct got_error *err = NULL;
100 	int fd;
101 
102 	*outfd = -1;
103 
104 	if (asprintf(path, "%s-XXXXXX", basepath) == -1) {
105 		*path = NULL;
106 		return got_error_from_errno("asprintf");
107 	}
108 
109 	fd = mkstemp(*path);
110 	if (fd == -1) {
111 		err = got_error_from_errno("mkstemp");
112 		free(*path);
113 		*path = NULL;
114 		return err;
115 	}
116 
117 	*outfd = fd;
118 	return err;
119 }
120 
121 const struct got_error *
122 got_opentemp_truncate(FILE *f)
123 {
124 	if (fpurge(f) == EOF)
125 		return got_error_from_errno("fpurge");
126 	if (ftruncate(fileno(f), 0L) == -1)
127 		return got_error_from_errno("ftruncate");
128 	if (fseeko(f, 0L, SEEK_SET) == -1)
129 		return got_error_from_errno("fseeko");
130 	return NULL;
131 }