Taint: fix dsearch result to be untainted
[exim.git] / src / src / lookups / dsearch.c
CommitLineData
0756eb3c
PH
1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
3386088d 5/* Copyright (c) University of Cambridge 1995 - 2015 */
0756eb3c
PH
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
0f2cbd1b
MH
9been heavily reworked a lot for Exim 4 (and it now uses stat() (more precisely:
10lstat()) rather than a directory scan). */
0756eb3c
PH
11
12
13#include "../exim.h"
14#include "lf_functions.h"
0756eb3c
PH
15
16
17
18/*************************************************
19* Open entry point *
20*************************************************/
21
22/* See local README for interface description. We open the directory to test
23whether it exists and whether it is searchable. However, we don't need to keep
0f2cbd1b 24it open, because the "search" can be done by a call to lstat() rather than
0756eb3c
PH
25actually scanning through the list of files. */
26
e6d225ae 27static void *
0756eb3c
PH
28dsearch_open(uschar *dirname, uschar **errmsg)
29{
30DIR *dp = opendir(CS dirname);
36b600bb 31if (!dp)
0756eb3c
PH
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 }
38closedir(dp);
39return (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
48integer as this gives warnings on 64-bit systems. */
49
36b600bb
JH
50static BOOL
51dsearch_check(void *handle, uschar *filename, int modemask, uid_t *owners,
0756eb3c
PH
52 gid_t *owngroups, uschar **errmsg)
53{
54handle = handle;
55return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
56 "dsearch", errmsg) == 0;
57}
58
59
60/*************************************************
61* Find entry point *
62*************************************************/
63
0f2cbd1b 64/* See local README for interface description. We use lstat() instead of
0756eb3c
PH
65scanning the directory, as it is hopefully faster to let the OS do the scanning
66for us. */
67
13e70f55
JH
68static int
69dsearch_find(void *handle, uschar *dirname, const uschar *keystring, int length,
14b3c5bc 70 uschar **result, uschar **errmsg, uint *do_cache)
0756eb3c
PH
71{
72struct stat statbuf;
73int save_errno;
13e70f55 74uschar * filename;
0756eb3c
PH
75
76handle = handle; /* Keep picky compilers happy */
77length = length;
78do_cache = do_cache;
79
80if (Ustrchr(keystring, '/') != 0)
81 {
82 *errmsg = string_sprintf("key for dsearch lookup contains a slash: %s",
83 keystring);
84 return DEFER;
85 }
86
13e70f55 87filename = string_sprintf("%s/%s", dirname, keystring);
0f2cbd1b 88if (Ulstat(filename, &statbuf) >= 0)
0756eb3c 89 {
36b600bb
JH
90 /* Since the filename exists in the filesystem, we can return a
91 non-tainted result. */
92 *result = string_copy_taint(keystring, FALSE);
0756eb3c
PH
93 return OK;
94 }
95
96if (errno == ENOENT) return FAIL;
97
98save_errno = errno;
0f2cbd1b 99*errmsg = string_sprintf("%s: lstat failed", filename);
0756eb3c
PH
100errno = save_errno;
101return DEFER;
102}
103
104
105/*************************************************
106* Close entry point *
107*************************************************/
108
109/* See local README for interface description */
110
111void
e6d225ae 112static dsearch_close(void *handle)
0756eb3c
PH
113{
114handle = handle; /* Avoid compiler warning */
115}
116
6545de78
PP
117
118/*************************************************
119* Version reporting entry point *
120*************************************************/
121
122/* See local README for interface description. */
123
124#include "../version.h"
125
126void
127dsearch_version_report(FILE *f)
128{
129#ifdef DYNLOOKUP
130fprintf(f, "Library version: dsearch: Exim version %s\n", EXIM_VERSION_STR);
131#endif
132}
133
134
e6d225ae
DW
135static lookup_info _lookup_info = {
136 US"dsearch", /* lookup name */
137 lookup_absfile, /* uses absolute file name */
138 dsearch_open, /* open function */
139 dsearch_check, /* check function */
140 dsearch_find, /* find function */
141 dsearch_close, /* close function */
142 NULL, /* no tidy function */
6545de78
PP
143 NULL, /* no quoting function */
144 dsearch_version_report /* version reporting */
e6d225ae
DW
145};
146
147#ifdef DYNLOOKUP
148#define dsearch_lookup_module_info _lookup_module_info
149#endif
150
151static lookup_info *_lookup_list[] = { &_lookup_info };
152lookup_module_info dsearch_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
153
0756eb3c 154/* End of lookups/dsearch.c */