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 		if (unlink(name) == -1) {
41 			close(fd);
42 			return -1;
43 		}
44 	}
45 	return fd;
46 }
47 
48 FILE *
49 got_opentemp(void)
50 {
51 	int fd;
52 	FILE *f;
53 
54 	fd = got_opentempfd();
55 	if (fd < 0)
56 		return NULL;
57 
58 	f = fdopen(fd, "w+");
59 	if (f == NULL) {
60 		close(fd);
61 		return NULL;
62 	}
63 
64 	return f;
65 }
66 
67 const struct got_error *
68 got_opentemp_named(char **path, FILE **outfile, const char *basepath,
69     const char *suffix)
70 {
71 	const struct got_error *err = NULL;
72 	int fd;
73 
74 	*outfile = NULL;
75 
76 	if (asprintf(path, "%s-XXXXXX%s", basepath, suffix) == -1) {
77 		*path = NULL;
78 		return got_error_from_errno("asprintf");
79 	}
80 
81 	fd = mkstemps(*path, strlen(suffix));
82 	if (fd == -1) {
83 		err = got_error_from_errno2("mkstemps", *path);
84 		free(*path);
85 		*path = NULL;
86 		return err;
87 	}
88 
89 	*outfile = fdopen(fd, "w+");
90 	if (*outfile == NULL) {
91 		err = got_error_from_errno2("fdopen", *path);
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-XXXXXX%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_errno("mkstemp");
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 }