ftp: remove temporary fields from state

As input, input_len and direction only last for the scope of
one call of AppLayerParserParse, it is not necessary to keep them
in FtpState which lives longer, so we consume less memory.

src/app-layer-ftp.c

@@ -369,7 +369,12 @@ static void FTPTransactionFree(FTPTransaction *tx)
     FTPFree(tx, sizeof(*tx));
 }
 
-static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
+typedef struct FtpInput_ {
+    const uint8_t *input;
+    int32_t input_len;
+} FtpInput;
+
+static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state, FtpInput *ftpi)
 {
     void *ptmp;
     if (line_state->current_line_lf_seen == 1) {
@@ -388,9 +393,9 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
     }
 
     /* Should be guaranteed by the caller. */
-    DEBUG_VALIDATE_BUG_ON(state->input_len <= 0);
+    DEBUG_VALIDATE_BUG_ON(ftpi->input_len <= 0);
 
-    uint8_t *lf_idx = memchr(state->input, 0x0a, state->input_len);
+    uint8_t *lf_idx = memchr(ftpi->input, 0x0a, ftpi->input_len);
 
     if (lf_idx == NULL) {
         /* fragmented lines.  Decoder event for special cases.  Not all
@@ -400,7 +405,7 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
          * if we see fragmentation then it's definitely something you
          * should alert about */
         if (line_state->current_line_db == 0) {
-            int32_t input_len = state->input_len;
+            int32_t input_len = ftpi->input_len;
             if ((uint32_t)input_len > ftp_max_line_len) {
                 input_len = ftp_max_line_len;
                 state->current_line_truncated = true;
@@ -410,10 +415,10 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
                 return -1;
             }
             line_state->current_line_db = 1;
-            memcpy(line_state->db, state->input, input_len);
+            memcpy(line_state->db, ftpi->input, input_len);
             line_state->db_len = input_len;
         } else if (!state->current_line_truncated) {
-            int32_t input_len = state->input_len;
+            int32_t input_len = ftpi->input_len;
             if (line_state->db_len + input_len > ftp_max_line_len) {
                 input_len = ftp_max_line_len - line_state->db_len;
                 DEBUG_VALIDATE_BUG_ON(input_len < 0);
@@ -430,12 +435,12 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
                 }
                 line_state->db = ptmp;
 
-                memcpy(line_state->db + line_state->db_len, state->input, input_len);
+                memcpy(line_state->db + line_state->db_len, ftpi->input, input_len);
                 line_state->db_len += input_len;
             }
         }
-        state->input += state->input_len;
+        ftpi->input += ftpi->input_len;
-        state->input_len = 0;
+        ftpi->input_len = 0;
 
         return -1;
 
@@ -444,7 +449,7 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
 
         if (line_state->current_line_db == 1) {
             if (!state->current_line_truncated) {
-                int32_t input_len = lf_idx + 1 - state->input;
+                int32_t input_len = lf_idx + 1 - ftpi->input;
                 if (line_state->db_len + input_len > ftp_max_line_len) {
                     input_len = ftp_max_line_len - line_state->db_len;
                     DEBUG_VALIDATE_BUG_ON(input_len < 0);
@@ -461,7 +466,7 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
                     }
                     line_state->db = ptmp;
 
-                    memcpy(line_state->db + line_state->db_len, state->input, input_len);
+                    memcpy(line_state->db + line_state->db_len, ftpi->input, input_len);
                     line_state->db_len += input_len;
 
                     if (line_state->db_len > 1 && line_state->db[line_state->db_len - 2] == 0x0D) {
@@ -478,16 +483,15 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
             state->current_line_len = line_state->db_len;
 
         } else {
-            state->current_line = state->input;
+            state->current_line = ftpi->input;
-            if (lf_idx - state->input > ftp_max_line_len) {
+            if (lf_idx - ftpi->input > ftp_max_line_len) {
                 state->current_line_len = ftp_max_line_len;
                 state->current_line_truncated = true;
             } else {
-                state->current_line_len = lf_idx - state->input;
+                state->current_line_len = lf_idx - ftpi->input;
             }
 
-            if (state->input != lf_idx &&
+            if (ftpi->input != lf_idx && *(lf_idx - 1) == 0x0D) {
-                *(lf_idx - 1) == 0x0D) {
                 state->current_line_len--;
                 state->current_line_delimiter_len = 2;
             } else {
@@ -495,27 +499,27 @@ static int FTPGetLineForDirection(FtpState *state, FtpLineState *line_state)
             }
         }
 
-        state->input_len -= (lf_idx - state->input) + 1;
+        ftpi->input_len -= (lf_idx - ftpi->input) + 1;
-        state->input = (lf_idx + 1);
+        ftpi->input = (lf_idx + 1);
 
         return 0;
     }
 
 }
 
-static int FTPGetLine(FtpState *state)
+static int FTPGetLine(FtpState *state, int direction, FtpInput *ftpi)
 {
     SCEnter();
 
     /* we have run out of input */
-    if (state->input_len <= 0)
+    if (ftpi->input_len <= 0)
         return -1;
 
     /* toserver */
-    if (state->direction == 0)
+    if (direction == STREAM_TOSERVER)
-        return FTPGetLineForDirection(state, &state->line_state[0]);
+        return FTPGetLineForDirection(state, &state->line_state[0], ftpi);
     else
-        return FTPGetLineForDirection(state, &state->line_state[1]);
+        return FTPGetLineForDirection(state, &state->line_state[1], ftpi);
 }
 
 /**
@@ -619,13 +623,10 @@ static AppLayerResult FTPParseRequest(Flow *f, void *ftp_state, AppLayerParserSt
         SCReturnStruct(APP_LAYER_ERROR);
     }
 
-    state->input = input;
+    FtpInput ftpi = { .input = input, .input_len = input_len };
-    state->input_len = input_len;
-    /* toserver stream */
-    state->direction = 0;
 
     int direction = STREAM_TOSERVER;
-    while (FTPGetLine(state) >= 0) {
+    while (FTPGetLine(state, STREAM_TOSERVER, &ftpi) >= 0) {
         const FtpCommand *cmd_descriptor;
 
         if (!FTPParseRequestCommand(thread_data,
@@ -802,13 +803,10 @@ static AppLayerResult FTPParseResponse(Flow *f, void *ftp_state, AppLayerParserS
     if (unlikely(input_len == 0)) {
         SCReturnStruct(APP_LAYER_OK);
     }
-    state->input = input;
+    FtpInput ftpi = { .input = input, .input_len = input_len };
-    state->input_len = input_len;
-    /* toclient stream */
-    state->direction = 1;
 
     FTPTransaction *lasttx = TAILQ_FIRST(&state->tx_list);
-    while (FTPGetLine(state) >= 0) {
+    while (FTPGetLine(state, STREAM_TOCLIENT, &ftpi) >= 0) {
         FTPTransaction *tx = FTPGetOldestTx(state, lasttx);
         if (tx == NULL) {
             tx = FTPTransactionCreate(state);

src/app-layer-ftp.h

@@ -160,9 +160,6 @@ typedef struct FTPTransaction_  {
 
 /** FTP State for app layer parser */
 typedef struct FtpState_ {
-    const uint8_t *input;
-    int32_t input_len;
-    uint8_t direction;
     bool active;
 
     FTPTransaction *curr_tx;