c27f5d6e65203f9d01d984012ab3566c067bb997
[exim.git] / src / src / lookups / dsearch.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2015 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* The idea for this code came from Matthew Byng-Maddick, but his original has
9 been heavily reworked a lot for Exim 4 (and it now uses stat() (more precisely:
10 lstat()) rather than a directory scan). */
11
12
13 #include "../exim.h"
14 #include "lf_functions.h"
15
16
17
18 /*************************************************
19 * Open entry point *
20 *************************************************/
21
22 /* See local README for interface description. We open the directory to test
23 whether it exists and whether it is searchable. However, we don't need to keep
24 it open, because the "search" can be done by a call to lstat() rather than
25 actually scanning through the list of files. */
26
27 static void *
28 dsearch_open(uschar *dirname, uschar **errmsg)
29 {
30 DIR *dp = opendir(CS dirname);
31 if (dp == NULL)
32 {
33 int save_errno = errno;
34 *errmsg = string_open_failed(errno, "%s for directory search", dirname);
35 errno = save_errno;
36 return NULL;
37 }
38 closedir(dp);
39 return (void *)(-1);
40 }
41
42
43 /*************************************************
44 * Check entry point *
45 *************************************************/
46
47 /* The handle will always be (void *)(-1), but don't try casting it to an
48 integer as this gives warnings on 64-bit systems. */
49
50 BOOL
51 static dsearch_check(void *handle, uschar *filename, int modemask, uid_t *owners,
52 gid_t *owngroups, uschar **errmsg)
53 {
54 handle = handle;
55 return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
56 "dsearch", errmsg) == 0;
57 }
58
59
60 /*************************************************
61 * Find entry point *
62 *************************************************/
63
64 /* See local README for interface description. We use lstat() instead of
65 scanning the directory, as it is hopefully faster to let the OS do the scanning
66 for us. */
67
68 static int
69 dsearch_find(void *handle, uschar *dirname, const uschar *keystring, int length,
70 uschar **result, uschar **errmsg, uint *do_cache)
71 {
72 struct stat statbuf;
73 int save_errno;
74 uschar * filename;
75
76 handle = handle; /* Keep picky compilers happy */
77 length = length;
78 do_cache = do_cache;
79
80 if (Ustrchr(keystring, '/') != 0)
81 {
82 *errmsg = string_sprintf("key for dsearch lookup contains a slash: %s",
83 keystring);
84 return DEFER;
85 }
86
87 filename = string_sprintf("%s/%s", dirname, keystring);
88 if (Ulstat(filename, &statbuf) >= 0)
89 {
90 *result = string_copy(keystring);
91 return OK;
92 }
93
94 if (errno == ENOENT) return FAIL;
95
96 save_errno = errno;
97 *errmsg = string_sprintf("%s: lstat failed", filename);
98 errno = save_errno;
99 return DEFER;
100 }
101
102
103 /*************************************************
104 * Close entry point *
105 *************************************************/
106
107 /* See local README for interface description */
108
109 void
110 static dsearch_close(void *handle)
111 {
112 handle = handle; /* Avoid compiler warning */
113 }
114
115
116 /*************************************************
117 * Version reporting entry point *
118 *************************************************/
119
120 /* See local README for interface description. */
121
122 #include "../version.h"
123
124 void
125 dsearch_version_report(FILE *f)
126 {
127 #ifdef DYNLOOKUP
128 fprintf(f, "Library version: dsearch: Exim version %s\n", EXIM_VERSION_STR);
129 #endif
130 }
131
132
133 static lookup_info _lookup_info = {
134 US"dsearch", /* lookup name */
135 lookup_absfile, /* uses absolute file name */
136 dsearch_open, /* open function */
137 dsearch_check, /* check function */
138 dsearch_find, /* find function */
139 dsearch_close, /* close function */
140 NULL, /* no tidy function */
141 NULL, /* no quoting function */
142 dsearch_version_report /* version reporting */
143 };
144
145 #ifdef DYNLOOKUP
146 #define dsearch_lookup_module_info _lookup_module_info
147 #endif
148
149 static lookup_info *_lookup_list[] = { &_lookup_info };
150 lookup_module_info dsearch_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
151
152 /* End of lookups/dsearch.c */