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.XXXXXXXXXX", 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     const char *suffix)
68 {
69 	const struct got_error *err = NULL;
70 	int fd;
71 
72 	*outfile = NULL;
73 
74 	if (asprintf(path, "%s-XXXXXXXXXX%s", basepath, suffix) == -1) {
75 		*path = NULL;
76 		return got_error_from_errno("asprintf");
77 	}
78 
79 	fd = mkstemps(*path, strlen(suffix));
80 	if (fd == -1) {
81 		err = got_error_from_errno2("mkstemps", *path);
82 		free(*path);
83 		*path = NULL;
84 		return err;
85 	}
86 
87 	*outfile = fdopen(fd, "w+");
88 	if (*outfile == NULL) {
89 		err = got_error_from_errno2("fdopen", *path);
90 		close(fd);
91 		free(*path);
92 		*path = NULL;
93 	}
94 
95 	return err;
96 }
97 
98 const struct got_error *
99 got_opentemp_named_fd(char **path, int *outfd, const char *basepath,
100     const char *suffix)
101 {
102 	const struct got_error *err = NULL;
103 	int fd;
104 
105 	*outfd = -1;
106 
107 	if (asprintf(path, "%s-XXXXXXXXXX%s", basepath, suffix) == -1) {
108 		*path = NULL;
109 		return got_error_from_errno("asprintf");
110 	}
111 
112 	fd = mkstemps(*path, strlen(suffix));
113 	if (fd == -1) {
114 		err = got_error_from_errno("mkstemp");
115 		free(*path);
116 		*path = NULL;
117 		return err;
118 	}
119 
120 	*outfd = fd;
121 	return err;
122 }
123 
124 const struct got_error *
125 got_opentemp_truncate(FILE *f)
126 {
127 	if (fpurge(f) == EOF)
128 		return got_error_from_errno("fpurge");
129 	if (ftruncate(fileno(f), 0L) == -1)
130 		return got_error_from_errno("ftruncate");
131 	if (fseeko(f, 0L, SEEK_SET) == -1)
132 		return got_error_from_errno("fseeko");
133 	return NULL;
134 }
135 
136 const struct got_error *
137 got_opentemp_truncatefd(int fd)
138 {
139 	if (ftruncate(fd, 0L) == -1)
140 		return got_error_from_errno("ftruncate");
141 	if (lseek(fd, 0L, SEEK_SET) == -1)
142 		return got_error_from_errno("lseek");
143 	return NULL;
144 }