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_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 }
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 }