parser: split tcp option rules

At this time the parser will accept nonsensical input like

 tcp option mss left 2

which will be treated as 'tcp option maxseg size 2'.
This is because the enum space overlaps.

Split the rules so that 'tcp option mss' will only
accept field names specific to the mss/maxseg option kind.

Signed-off-by: Florian Westphal <fw@strlen.de>
(cherry picked from commit 46168852c03d73c29b557c93029dc512ca6e233a)

diff --git a/src/parser_bison.y b/src/parser_bison.y
index 2606098534e6a00829bd7620fb21c34d29438631..fca79132609478a2de5e57941b05beb51ee21197 100644 (file)
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -187,6 +187,10 @@ int nft_lex(void *, void *, void *);
        struct position_spec    position_spec;
        struct prio_spec        prio_spec;
        struct limit_rate       limit_rate;
+       struct tcp_kind_field {
+               uint16_t kind; /* must allow > 255 for SACK1, 2.. hack */
+               uint8_t field;
+       } tcp_kind_field;
 }
 
 %token TOKEN_EOF 0             "end of file"
@@ -873,7 +877,10 @@ int nft_lex(void *, void *, void *);
 %type <expr>                   tcp_hdr_expr
 %destructor { expr_free($$); } tcp_hdr_expr
 %type <val>                    tcp_hdr_field
-%type <val>                    tcp_hdr_option_type tcp_hdr_option_field
+%type <val>                    tcp_hdr_option_type
+%type <val>                    tcp_hdr_option_sack
+%type <val>                    tcpopt_field_maxseg     tcpopt_field_sack        tcpopt_field_tsopt     tcpopt_field_window
+%type <tcp_kind_field>         tcp_hdr_option_kind_and_field
 
 %type <expr>                   boolean_expr
 %destructor { expr_free($$); } boolean_expr
@@ -5477,15 +5484,15 @@ tcp_hdr_expr            :       TCP     tcp_hdr_field
                        {
                                $$ = payload_expr_alloc(&@$, &proto_tcp, $2);
                        }
-                       |       TCP     OPTION  tcp_hdr_option_type tcp_hdr_option_field
-                       {
-                               $$ = tcpopt_expr_alloc(&@$, $3, $4);
-                       }
                        |       TCP     OPTION  tcp_hdr_option_type
                        {
                                $$ = tcpopt_expr_alloc(&@$, $3, TCPOPT_COMMON_KIND);
                                $$->exthdr.flags = NFT_EXTHDR_F_PRESENT;
                        }
+                       |       TCP     OPTION  tcp_hdr_option_kind_and_field
+                       {
+                               $$ = tcpopt_expr_alloc(&@$, $3.kind, $3.field);
+                       }
                        |       TCP     OPTION  AT tcp_hdr_option_type  COMMA   NUM     COMMA   NUM
                        {
                                $$ = tcpopt_expr_alloc(&@$, $4, 0);
@@ -5505,19 +5512,49 @@ tcp_hdr_field           :       SPORT           { $$ = TCPHDR_SPORT; }
                        |       URGPTR          { $$ = TCPHDR_URGPTR; }
                        ;
 
-tcp_hdr_option_type    :       EOL             { $$ = TCPOPT_KIND_EOL; }
-                       |       NOP             { $$ = TCPOPT_KIND_NOP; }
-                       |       MSS             { $$ = TCPOPT_KIND_MAXSEG; }
-                       |       WINDOW          { $$ = TCPOPT_KIND_WINDOW; }
-                       |       SACK_PERM       { $$ = TCPOPT_KIND_SACK_PERMITTED; }
-                       |       SACK            { $$ = TCPOPT_KIND_SACK; }
+tcp_hdr_option_kind_and_field  :       MSS     tcpopt_field_maxseg
+                               {
+                                       struct tcp_kind_field kind_field = { .kind = TCPOPT_KIND_MAXSEG, .field = $2 };
+                                       $$ = kind_field;
+                               }
+                               |       tcp_hdr_option_sack     tcpopt_field_sack
+                               {
+                                       struct tcp_kind_field kind_field = { .kind = $1, .field = $2 };
+                                       $$ = kind_field;
+                               }
+                               |       WINDOW  tcpopt_field_window
+                               {
+                                       struct tcp_kind_field kind_field = { .kind = TCPOPT_KIND_WINDOW, .field = $2 };
+                                       $$ = kind_field;
+                               }
+                               |       TIMESTAMP       tcpopt_field_tsopt
+                               {
+                                       struct tcp_kind_field kind_field = { .kind = TCPOPT_KIND_TIMESTAMP, .field = $2 };
+                                       $$ = kind_field;
+                               }
+                               |       tcp_hdr_option_type     LENGTH
+                               {
+                                       struct tcp_kind_field kind_field = { .kind = $1, .field = TCPOPT_COMMON_LENGTH };
+                                       $$ = kind_field;
+                               }
+                               ;
+
+tcp_hdr_option_sack    :       SACK            { $$ = TCPOPT_KIND_SACK; }
                        |       SACK0           { $$ = TCPOPT_KIND_SACK; }
                        |       SACK1           { $$ = TCPOPT_KIND_SACK1; }
                        |       SACK2           { $$ = TCPOPT_KIND_SACK2; }
                        |       SACK3           { $$ = TCPOPT_KIND_SACK3; }
-                       |       ECHO            { $$ = TCPOPT_KIND_ECHO; }
-                       |       TIMESTAMP       { $$ = TCPOPT_KIND_TIMESTAMP; }
-                       |       NUM             {
+                       ;
+
+tcp_hdr_option_type    :       ECHO                    { $$ = TCPOPT_KIND_ECHO; }
+                       |       EOL                     { $$ = TCPOPT_KIND_EOL; }
+                       |       MSS                     { $$ = TCPOPT_KIND_MAXSEG; }
+                       |       NOP                     { $$ = TCPOPT_KIND_NOP; }
+                       |       SACK_PERM               { $$ = TCPOPT_KIND_SACK_PERMITTED; }
+                       |       TIMESTAMP               { $$ = TCPOPT_KIND_TIMESTAMP; }
+                       |       WINDOW                  { $$ = TCPOPT_KIND_WINDOW; }
+                       |       tcp_hdr_option_sack     { $$ = $1; }
+                       |       NUM                     {
                                if ($1 > 255) {
                                        erec_queue(error(&@1, "value too large"), state->msgs);
                                        YYERROR;
@@ -5526,15 +5563,20 @@ tcp_hdr_option_type     :       EOL             { $$ = TCPOPT_KIND_EOL; }
                        }
                        ;
 
-tcp_hdr_option_field   :       LENGTH          { $$ = TCPOPT_COMMON_LENGTH; }
-                       |       SIZE            { $$ = TCPOPT_MAXSEG_SIZE; }
-                       |       COUNT           { $$ = TCPOPT_WINDOW_COUNT; }
-                       |       LEFT            { $$ = TCPOPT_SACK_LEFT; }
+tcpopt_field_sack      :       LEFT            { $$ = TCPOPT_SACK_LEFT; }
                        |       RIGHT           { $$ = TCPOPT_SACK_RIGHT; }
-                       |       TSVAL           { $$ = TCPOPT_TS_TSVAL; }
+                       ;
+
+tcpopt_field_window    :       COUNT           { $$ = TCPOPT_WINDOW_COUNT; }
+                       ;
+
+tcpopt_field_tsopt     :       TSVAL           { $$ = TCPOPT_TS_TSVAL; }
                        |       TSECR           { $$ = TCPOPT_TS_TSECR; }
                        ;
 
+tcpopt_field_maxseg    :       SIZE            { $$ = TCPOPT_MAXSEG_SIZE; }
+                       ;
+
 dccp_hdr_expr          :       DCCP    dccp_hdr_field
                        {
                                $$ = payload_expr_alloc(&@$, &proto_dccp, $2);