From: Jeff Lucovsky <jeff@lucovsky.org>
Date: Wed, 28 Aug 2019 22:54:14 +0000 (-0400)
Subject: ftp: Use rust parsers to parse dynamic ports
X-Git-Tag: suricata-5.0.0-rc1~19
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b4070b6dcd7942521181771de1d9b2fdb9db2d50;p=thirdparty%2Fsuricata.git

ftp: Use rust parsers to parse dynamic ports
---

diff --git a/src/app-layer-ftp.c b/src/app-layer-ftp.c
index b2035378ce..6d29d5be1b 100644
--- a/src/app-layer-ftp.c
+++ b/src/app-layer-ftp.c
@@ -540,69 +540,6 @@ static uint32_t CopyCommandLine(uint8_t **dest, const uint8_t *src, uint32_t len
     return length;
 }
 
-static uint16_t ftp_validate_port(int computed_port_value)
-{
-    unsigned int port_val = computed_port_value;
-
-    if (port_val && port_val > UINT16_MAX)
-        return 0;
-
-    return ((uint16_t) (port_val));
-}
-
-/**
- * \brief This function extracts a port number from the command input line for IPv6 FTP usage
- * \param input input line of the command
- * \param input_len length of the request
- *
- * \retval 0 if a port number could not be extracted; otherwise, the dynamic port number
- */
-static uint16_t FTPGetV6PortNumber(const uint8_t *input, uint32_t input_len)
-{
-    uint16_t res;
-
-    uint8_t *ptr = memrchr(input, '|', input_len);
-    if (ptr == NULL) {
-        return 0;
-    }
-
-    int n_length = ptr - input - 1;
-    if (n_length < 4)
-        return 0;
-
-    ptr = memrchr(input, '|', n_length);
-    if (ptr == NULL)
-        return 0;
-
-    if (ByteExtractStringUint16(&res, 10, 0, (const char *)ptr + 1) < 0) {
-        return 0;
-    }
-    return res;
-}
-
-/**
- * \brief This function extracts a port number from the command input line for IPv4 FTP usage
- * \param input input line of the command
- * \param input_len length of the request
- *
- * \retval 0 if a port number could not be extracted; otherwise, the dynamic port number
- */
-static uint16_t FTPGetV4PortNumber(const uint8_t *input, uint32_t input_len)
-{
-    uint16_t part1, part2;
-    uint8_t *ptr = memrchr(input, ',', input_len);
-    if (ptr == NULL)
-        return 0;
-
-    part2 = atoi((char *)ptr + 1);
-    ptr = memrchr(input, ',', (ptr - input) - 1);
-    if (ptr == NULL)
-        return 0;
-    part1 = atoi((char *)ptr + 1);
-
-    return ftp_validate_port(256 * part1 + part2);
-}
-
 
 /**
  * \brief This function is called to retrieve a ftp request
@@ -663,7 +600,7 @@ static int FTPParseRequest(Flow *f, void *ftp_state,
                 if (state->current_line_len + 1 > state->port_line_size) {
                     /* Allocate an extra byte for a NULL terminator */
                     ptmp = FTPRealloc(state->port_line, state->port_line_size,
-                                      state->current_line_len + 1);
+                                      state->current_line_len);
                     if (ptmp == NULL) {
                         if (state->port_line) {
                             FTPFree(state->port_line, state->port_line_size);
@@ -673,11 +610,10 @@ static int FTPParseRequest(Flow *f, void *ftp_state,
                         return 0;
                     }
                     state->port_line = ptmp;
-                    state->port_line_size = state->current_line_len + 1;
+                    state->port_line_size = state->current_line_len;
                 }
                 memcpy(state->port_line, state->current_line,
                         state->current_line_len);
-                state->port_line[state->current_line_len] = '\0';
                 state->port_line_len = state->current_line_len;
                 break;
             case FTP_COMMAND_RETR:
@@ -818,7 +754,7 @@ static int FTPParseResponse(Flow *f, void *ftp_state, AppLayerParserState *pstat
     }
 
     if (state->command == FTP_COMMAND_EPRT) {
-        uint16_t dyn_port = FTPGetV6PortNumber(state->port_line, state->port_line_len);
+        uint16_t dyn_port = rs_ftp_active_eprt(state->port_line, state->port_line_len);
         if (dyn_port == 0) {
             retcode = 0;
             goto tx_complete;
@@ -832,7 +768,7 @@ static int FTPParseResponse(Flow *f, void *ftp_state, AppLayerParserState *pstat
 
     if (state->command == FTP_COMMAND_PORT) {
         if ((flags & STREAM_TOCLIENT)) {
-            uint16_t dyn_port = FTPGetV4PortNumber(state->port_line, state->port_line_len);
+            uint16_t dyn_port = rs_ftp_active_port(state->port_line, state->port_line_len);
             if (dyn_port == 0) {
                 retcode = 0;
                 goto tx_complete;