Simplify payload length storage

commandline.c

@@ -1525,22 +1525,6 @@ int app_count_peers(int argc, const char *const *argv, struct command_line_optio
   return 0;
 }
 
-int app_test_rfs(int argc, const char *const *argv, struct command_line_option *o, void *context)
-{
-  if (debug & DEBUG_VERBOSE) DEBUG_argv("command", argc, argv);
-  printf("Testing that RFS coder works properly.\n");
-  int i;
-  for(i=0;i<65536;i++) {
-    unsigned char bytes[8];
-    rfs_encode(i, &bytes[0]);
-    int zero=0;
-    int r=rfs_decode(&bytes[0],&zero);
-    if (i != r)
-      printf("RFS encoding of %d decodes to %d: %s\n", i, r, alloca_tohex(bytes, sizeof bytes));
-  }
-  return 0;
-}
-
 int app_crypt_test(int argc, const char *const *argv, struct command_line_option *o, void *context)
 {
   if (debug & DEBUG_VERBOSE) DEBUG_argv("command", argc, argv);
@@ -1940,8 +1924,6 @@ struct command_line_option command_line_options[]={
     "Return a count of routable peers on the network"},
   {app_reverse_lookup, {"reverse", "lookup", "<sid>", "[<timeout>]", NULL}, 0,
     "Lookup the phone number and name of a given subscriber"},
-  {app_test_rfs,{"test","rfs",NULL},0,
-   "Test RFS field calculation"},
   {app_monitor_cli,{"monitor",NULL},0,
    "Interactive servald monitor interface."},
   {app_crypt_test,{"crypt","test",NULL},0,

constants.h

@@ -112,15 +112,6 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 /* QOS packet queue bits */
 #define OF_QUEUE_BITS 0x03
 
-#define RFS_PLUS250 0xfa
-#define RFS_PLUS456 0xfb
-#define RFS_PLUS762 0xfc
-#define RFS_PLUS1018 0xfd
-#define RFS_PLUS1274 0xfe
-#define RFS_3BYTE 0xff
-
-#define COMPUTE_RFS_LENGTH -1
-
 /* Keep track of last 32 observations of a node.
    Hopefully this is enough, if not, we will increase.
    To keep the requirement down we will collate contigious neighbour observations on each interface.

overlay_advertise.c

@@ -165,7 +165,7 @@ int overlay_route_add_advertisements(struct decode_context *context, overlay_int
     // no advertisements? don't bother to send the payload at all.
     ob_rewind(e);
   }else
-    ob_patch_rfs(e,COMPUTE_RFS_LENGTH);
+    ob_patch_rfs(e);
 
   return 0;
 }

overlay_buffer.c

@@ -255,24 +255,10 @@ int ob_append_ui32(struct overlay_buffer *b, uint32_t v)
 
 int ob_append_rfs(struct overlay_buffer *b,int l)
 {
-  /* Encode the specified length and append it to the buffer */
   if (l<0||l>0xffff) return -1;
   
-  /* First work out how long the field needs to be, then write dummy bytes
-   and use ob_patch_rfs to set the value.  That way we have only one
-   lot of code that does the encoding. */
-  
   b->var_length_offset=b->position;
-  b->var_length_bytes=rfs_length(l);
-  
-  unsigned char c[3]={0,0,0};
-  if (ob_append_bytes(b,c,b->var_length_bytes)) {
-    b->var_length_offset=0;
-    return -1;
-  }
-  
-  return ob_patch_rfs(b,l);
-  
+  return ob_append_ui16(b,l);
 }
 
 
@@ -348,96 +334,18 @@ int ob_get(struct overlay_buffer *b){
   return b->bytes[b->position++];
 }
 
-int rfs_length(int l)
+int ob_set_ui16(struct overlay_buffer *b, int offset, uint16_t v)
 {
-  if (l<0) return -1;
-  if (l<250) return 1;
-  else if (l<(255+250+(256*4))) return 2;
-  else if (l<=0xffff) return 3;
-  else return -1;
-}
-
-int rfs_encode(int l, unsigned char *b)
-{
-  if (l<250) { b[0]=l; }
-  else if (l<(255+250+(256*4))) {
-    l-=250;
-    int page=(l>>8);
-    l&=0xff;
-    b[0]=RFS_PLUS250+page;
-    b[1]=l;
-  } else {
-    b[0]=RFS_3BYTE;
-    b[1]=l>>8;
-    b[2]=l&0xff;
-  }
-  return 0;
-}
-
-int rfs_decode(unsigned char *b,int *ofs)
-{
-  int rfs=b[*ofs];
-  switch(rfs) {
-  case RFS_PLUS250: case RFS_PLUS456: case RFS_PLUS762: case RFS_PLUS1018: case RFS_PLUS1274: 
-    rfs=250+256*(rfs-RFS_PLUS250)+b[++(*ofs)]; 
-    break;
-  case RFS_3BYTE: rfs=(b[(*ofs)+1]<<8)+b[(*ofs)+2]; (*ofs)+=2;
-  default: /* Length is natural value of field, so nothing to do */
-    break;
-  }
-  (*ofs)++;
-  return rfs;
-}
-
-// move the data at offset, by shift bytes
-int ob_indel_space(struct overlay_buffer *b,int offset,int shift)
-{
-  if (offset>=b->position) return -1;
-  if (shift>0 && ob_makespace(b, shift)) return -1;
-  bcopy(&b->bytes[offset],&b->bytes[offset+shift],b->position-offset);
-  b->position+=shift;
-  return 0;
-}
-
-
-int ob_patch_rfs(struct overlay_buffer *b,int l)
-{
-  if (l==COMPUTE_RFS_LENGTH){
-    // assume the payload has been written, we can now calculate the actual length
-    l = b->position - (b->var_length_offset + b->var_length_bytes);
-  }
-  if (l<0||l>0xffff) return -1;
-
-  /* Adjust size of field */
-  int new_size=rfs_length(l);
-  int shift=new_size - b->var_length_bytes;
-  if (shift) {
-    if (debug&DEBUG_PACKETCONSTRUCTION) {
-      DEBUGF("Patching RFS for rfs_size=%d (was %d), so indel %d btyes",
-	      new_size,b->var_length_bytes,shift);
-      dump("before indel",
-	   &b->bytes[b->var_length_offset],
-	   b->position-b->var_length_offset);
-    }
-    if (ob_indel_space(b, b->var_length_offset + b->var_length_bytes, shift)) return -1;
-    if (debug&DEBUG_PACKETCONSTRUCTION) {
-      dump("after indel",
-	   &b->bytes[b->var_length_offset],
-	   b->position-b->var_length_offset);
-    }
-
-  }
+  if (test_offset(b, offset, 2))
+    return -1;
   
-  if (rfs_encode(l,&b->bytes[b->var_length_offset])) return -1;
-
-  if (debug&DEBUG_PACKETCONSTRUCTION) {
-    dump("after patch",
-	 &b->bytes[b->var_length_offset],
-	 b->position-b->var_length_offset);
-  }
-
+  b->bytes[offset] = (v >> 8) & 0xFF;
+  b->bytes[offset+1] = v & 0xFF;
   return 0;
-  
+}
+
+int ob_patch_rfs(struct overlay_buffer *b){
+  return ob_set_ui16(b,b->var_length_offset,b->position - (b->var_length_offset + 2));
 }
 
 int asprintable(int c)

overlay_buffer.h

@@ -38,9 +38,8 @@ struct overlay_buffer {
   // is this an allocated buffer? can it be resized? Should it be freed?
   int allocated;
   
-  // length position and size for later patching
+  // length position for later patching
   int var_length_offset;
-  int var_length_bytes;
 };
 
 struct overlay_buffer *ob_new(void);
@@ -58,7 +57,7 @@ int ob_append_bytes(struct overlay_buffer *b,unsigned char *bytes,int count);
 unsigned char *ob_append_space(struct overlay_buffer *b,int count);
 int ob_append_ui16(struct overlay_buffer *b, uint16_t v);
 int ob_append_ui32(struct overlay_buffer *b, uint32_t v);
-int ob_patch_rfs(struct overlay_buffer *b,int l);
+int ob_patch_rfs(struct overlay_buffer *b);
 int ob_append_rfs(struct overlay_buffer *b,int l);
 // get one byte, -ve number indicates failure
 int ob_getbyte(struct overlay_buffer *b,int ofs);
@@ -69,6 +68,7 @@ unsigned char * ob_get_bytes_ptr(struct overlay_buffer *b, int len);
 uint32_t ob_get_ui32(struct overlay_buffer *b);
 uint16_t ob_get_ui16(struct overlay_buffer *b);
 int ob_dump(struct overlay_buffer *b,char *desc);
+int ob_set_ui16(struct overlay_buffer *b, int offset, uint16_t v);
 
 
 #endif

overlay_packetformats.c

@@ -226,7 +226,7 @@ int packetOkOverlay(struct overlay_interface *interface,unsigned char *packet, s
     f.ttl--;
 
     /* Decode length of remainder of frame */
-    int payload_len=rfs_decode(b->bytes, &b->position);
+    int payload_len=ob_get_ui16(b);
 
     if (payload_len <=0) {
       /* assume we fell off the end of the packet */
@@ -409,7 +409,7 @@ int overlay_add_selfannouncement(struct decode_context *context, int interface,s
   if (ob_append_byte(b,interface))
     return WHY("Could not add interface number to self-announcement");
 
-  ob_patch_rfs(b, COMPUTE_RFS_LENGTH);
+  ob_patch_rfs(b);
   
   return 0;
 }

overlay_payload.c

@@ -98,7 +98,8 @@ int overlay_frame_append_payload(struct decode_context *context, overlay_interfa
   int actual_len=addrs_len+p->payload->position;
   if (debug&DEBUG_PACKETCONSTRUCTION) 
     DEBUGF("Patching RFS for actual_len=%d\n",actual_len);
-  ob_patch_rfs(headers,actual_len);
+  
+  ob_set_ui16(headers,headers->var_length_offset,actual_len);
 
   /* Write payload format plus total length of header bits */
   if (ob_makespace(b,2+headers->position+p->payload->position)) {

rhizome_packetformats.c

@@ -317,7 +317,7 @@ int overlay_rhizome_add_advertisements(struct decode_context *context, int inter
     }
   }
 
-  ob_patch_rfs(e, COMPUTE_RFS_LENGTH);
+  ob_patch_rfs(e);
 
   sqlite_set_debugmask(oldmask);
   RETURN(0);