From 548375b2122f83771dc0b8571f16e5b5adabba98 Mon Sep 17 00:00:00 2001
From: Martin Sehnoutka <msehnout@redhat.com>
Date: Wed, 7 Sep 2016 10:04:31 +0200
Subject: [PATCH 07/59] Make filename filters smarter.

In the original version vsftpd was not able to prevent
users from downloading for instance /etc/passwd by
defining filters such as deny_file=/etc/passwd or /etc*
or passwd. Example of erroneous behavior:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> cd /
250 Directory successfully changed.
ftp> cd /etc
550 Permission denied.
ftp> cd etc
250 Directory successfully changed.
ftp> get passwd
local: passwd remote: passwd
227 Entering Passive Mode (127,0,0,1,99,251)
150 Opening BINARY mode data connection for passwd (2813 bytes).
226 File send OK.
2813 bytes received in 0.00016 seconds (1.7e+04 Kbytes/s)
ftp> quit
221 Goodbye.
---
 ls.c  | 24 +++++++++++++++++++++++-
 str.c | 11 +++++++++++
 str.h |  1 +
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/ls.c b/ls.c
index 7e1376d..f489478 100644
--- a/ls.c
+++ b/ls.c
@@ -246,8 +246,30 @@ vsf_filename_passes_filter(const struct mystr* p_filename_str,
   int ret = 0;
   char last_token = 0;
   int must_match_at_current_pos = 1;
+
+
   str_copy(&filter_remain_str, p_filter_str);
-  str_copy(&name_remain_str, p_filename_str);
+
+  if (!str_isempty (&filter_remain_str) && !str_isempty(p_filename_str)) {
+    if (str_get_char_at(p_filter_str, 0) == '/') {
+      if (str_get_char_at(p_filename_str, 0) != '/') {
+        str_getcwd (&name_remain_str);
+
+        if (str_getlen(&name_remain_str) > 1) /* cwd != root dir */
+          str_append_char (&name_remain_str, '/');
+
+        str_append_str (&name_remain_str, p_filename_str);
+      }
+      else
+       str_copy (&name_remain_str, p_filename_str);
+    } else {
+      if (str_get_char_at(p_filter_str, 0) != '{')
+        str_basename (&name_remain_str, p_filename_str);
+      else
+        str_copy (&name_remain_str, p_filename_str);
+    }
+  } else
+    str_copy(&name_remain_str, p_filename_str);
 
   while (!str_isempty(&filter_remain_str) && *iters < VSFTP_MATCHITERS_MAX)
   {
diff --git a/str.c b/str.c
index 6596204..ba4b92a 100644
--- a/str.c
+++ b/str.c
@@ -711,3 +711,14 @@ str_replace_unprintable(struct mystr* p_str, char new_char)
   }
 }
 
+void
+str_basename (struct mystr* d_str, const struct mystr* path)
+{
+  static struct mystr tmp;
+
+  str_copy (&tmp, path);
+  str_split_char_reverse(&tmp, d_str, '/');
+
+  if (str_isempty(d_str))
+   str_copy (d_str, path);
+}
diff --git a/str.h b/str.h
index ab0a9a4..3a21b50 100644
--- a/str.h
+++ b/str.h
@@ -100,6 +100,7 @@ void str_replace_unprintable(struct mystr* p_str, char new_char);
 int str_atoi(const struct mystr* p_str);
 filesize_t str_a_to_filesize_t(const struct mystr* p_str);
 unsigned int str_octal_to_uint(const struct mystr* p_str);
+void str_basename (struct mystr* d_str, const struct mystr* path);
 
 /* PURPOSE: Extract a line of text (delimited by \n or EOF) from a string
  * buffer, starting at character position 'p_pos'. The extracted line will
-- 
2.14.4