X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/218c95cc2e45de929d92c508bc9a95292c3a4ece..a85c067ba6c6940512cf57ec213277a370d87e70:/src/src/lookups/dsearch.c

diff --git a/src/src/lookups/dsearch.c b/src/src/lookups/dsearch.c
index c27f5d6e6..6cae0dafb 100644
--- a/src/src/lookups/dsearch.c
+++ b/src/src/lookups/dsearch.c
@@ -2,8 +2,10 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
 /* Copyright (c) University of Cambridge 1995 - 2015 */
 /* See the file NOTICE for conditions of use and distribution. */
+/* SPDX-License-Identifier: GPL-2.0-only */
 
 /* The idea for this code came from Matthew Byng-Maddick, but his original has
 been heavily reworked a lot for Exim 4 (and it now uses stat() (more precisely:
@@ -25,14 +27,12 @@ it open, because the "search" can be done by a call to lstat() rather than
 actually scanning through the list of files. */
 
 static void *
-dsearch_open(uschar *dirname, uschar **errmsg)
+dsearch_open(const uschar * dirname, uschar ** errmsg)
 {
-DIR *dp = opendir(CS dirname);
-if (dp == NULL)
+DIR * dp = exim_opendir(dirname);
+if (!dp)
   {
-  int save_errno = errno;
-  *errmsg = string_open_failed(errno, "%s for directory search", dirname);
-  errno = save_errno;
+  *errmsg = string_open_failed("%s for directory search", dirname);
   return NULL;
   }
 closedir(dp);
@@ -47,13 +47,16 @@ return (void *)(-1);
 /* The handle will always be (void *)(-1), but don't try casting it to an
 integer as this gives warnings on 64-bit systems. */
 
-BOOL
-static dsearch_check(void *handle, uschar *filename, int modemask, uid_t *owners,
-  gid_t *owngroups, uschar **errmsg)
+static BOOL
+dsearch_check(void * handle, const uschar * filename, int modemask,
+  uid_t * owners, gid_t * owngroups, uschar ** errmsg)
 {
 handle = handle;
-return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
-  "dsearch", errmsg) == 0;
+if (*filename == '/')
+  return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
+    "dsearch", errmsg) == 0;
+*errmsg = string_sprintf("dirname '%s' for dsearch is not absolute", filename);
+return FALSE;
 }
 
 
@@ -61,21 +64,26 @@ return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
 *              Find entry point                  *
 *************************************************/
 
+#define RET_FULL	BIT(0)
+#define FILTER_TYPE	BIT(1)
+#define FILTER_ALL	BIT(1)
+#define FILTER_FILE	BIT(2)
+#define FILTER_DIR	BIT(3)
+#define FILTER_SUBDIR	BIT(4)
+
 /* See local README for interface description. We use lstat() instead of
 scanning the directory, as it is hopefully faster to let the OS do the scanning
 for us. */
 
 static int
-dsearch_find(void *handle, uschar *dirname, const uschar *keystring, int length,
-  uschar **result, uschar **errmsg, uint *do_cache)
+dsearch_find(void * handle, const uschar * dirname, const uschar * keystring,
+  int length, uschar ** result, uschar ** errmsg, uint * do_cache,
+  const uschar * opts)
 {
 struct stat statbuf;
 int save_errno;
 uschar * filename;
-
-handle = handle;  /* Keep picky compilers happy */
-length = length;
-do_cache = do_cache;
+unsigned flags = 0;
 
 if (Ustrchr(keystring, '/') != 0)
   {
@@ -84,17 +92,47 @@ if (Ustrchr(keystring, '/') != 0)
   return DEFER;
   }
 
+if (opts)
+  {
+  int sep = ',';
+  uschar * ele;
+
+  while ((ele = string_nextinlist(&opts, &sep, NULL, 0)))
+    if (Ustrcmp(ele, "ret=full") == 0)
+      flags |= RET_FULL;
+    else if (Ustrncmp(ele, "filter=", 7) == 0)
+      {
+      ele += 7;
+      if (Ustrcmp(ele, "file") == 0)
+	flags |= FILTER_TYPE | FILTER_FILE;
+      else if (Ustrcmp(ele, "dir") == 0)
+	flags |= FILTER_TYPE | FILTER_DIR;
+      else if (Ustrcmp(ele, "subdir") == 0)
+	flags |= FILTER_TYPE | FILTER_SUBDIR;	/* like dir but not "." or ".." */
+      }
+  }
+
 filename = string_sprintf("%s/%s", dirname, keystring);
-if (Ulstat(filename, &statbuf) >= 0)
+if (  Ulstat(filename, &statbuf) >= 0
+   && (  !(flags & FILTER_TYPE)
+      || (flags & FILTER_FILE && S_ISREG(statbuf.st_mode))
+      || (  flags & (FILTER_DIR | FILTER_SUBDIR)
+       	 && S_ISDIR(statbuf.st_mode)
+	 && (  flags & FILTER_DIR
+	    || keystring[0] != '.'
+	    || keystring[1] && keystring[1] != '.'
+   )  )  )  )
   {
-  *result = string_copy(keystring);
+  /* Since the filename exists in the filesystem, we can return a
+  non-tainted result. */
+  *result = string_copy_taint(flags & RET_FULL ? filename : keystring, GET_UNTAINTED);
   return OK;
   }
 
-if (errno == ENOENT) return FAIL;
+if (errno == ENOENT || errno == 0) return FAIL;
 
 save_errno = errno;
-*errmsg = string_sprintf("%s: lstat failed", filename);
+*errmsg = string_sprintf("%s: lstat: %s", filename, strerror(errno));
 errno = save_errno;
 return DEFER;
 }
@@ -121,25 +159,26 @@ handle = handle;   /* Avoid compiler warning */
 
 #include "../version.h"
 
-void
-dsearch_version_report(FILE *f)
+gstring *
+dsearch_version_report(gstring * g)
 {
 #ifdef DYNLOOKUP
-fprintf(f, "Library version: dsearch: Exim version %s\n", EXIM_VERSION_STR);
+g = string_fmt_append(g, "Library version: dsearch: Exim version %s\n", EXIM_VERSION_STR);
 #endif
+return g;
 }
 
 
 static lookup_info _lookup_info = {
-  US"dsearch",                   /* lookup name */
-  lookup_absfile,                /* uses absolute file name */
-  dsearch_open,                  /* open function */
-  dsearch_check,                 /* check function */
-  dsearch_find,                  /* find function */
-  dsearch_close,                 /* close function */
-  NULL,                          /* no tidy function */
-  NULL,                          /* no quoting function */
-  dsearch_version_report         /* version reporting */
+  .name = US"dsearch",			/* lookup name */
+  .type = lookup_absfile,		/* uses absolute file name */
+  .open = dsearch_open,			/* open function */
+  .check = dsearch_check,		/* check function */
+  .find = dsearch_find,			/* find function */
+  .close = dsearch_close,		/* close function */
+  .tidy = NULL,				/* no tidy function */
+  .quote = NULL,			/* no quoting function */
+  .version_report = dsearch_version_report         /* version reporting */
 };
 
 #ifdef DYNLOOKUP