Choose correct abstraction for topic_foo. Abstract random-integer code

svn:r249

doc/tor-spec.txt

@@ -228,8 +228,8 @@ which reveals the downstream node.
 
         ACI (anonymous circuit identifier)    [2 bytes]
         Command                               [1 byte]
-        Length                                [1 byte]
         Sequence number (unused, set to 0)    [4 bytes]
+        Length                                [1 byte]
         Payload (padded with 0 bytes)         [248 bytes]
                                          [Total size: 256 bytes]
 

src/common/crypto.h

@@ -85,6 +85,8 @@ int crypto_SHA_digest(unsigned char *m, int len, unsigned char *digest);
 int crypto_rand(unsigned int n, unsigned char *to);
 int crypto_pseudo_rand(unsigned int n, unsigned char *to);
 
+#define CRYPTO_PSEUDO_RAND_INT(v) crypto_pseudo_rand(sizeof(v),(char*)&(v))
+
 /* errors */
 char *crypto_perror();
 #endif

src/or/circuit.c

@@ -118,7 +118,8 @@ aci_t get_unique_aci_by_addr_port(uint32_t addr, uint16_t port, int aci_type) {
 try_again:
   log(LOG_DEBUG,"get_unique_aci_by_addr_port() trying to get a unique aci");
 
-  crypto_pseudo_rand(2, (unsigned char *)&test_aci);
+  if (CRYPTO_PSEUDO_RAND_INT(test_aci))
+    return -1;
 
   if(aci_type == ACI_TYPE_LOWER && test_aci >= (1<<15))
     test_aci -= (1<<15);

src/or/connection.c

@@ -698,8 +698,8 @@ repeat_connection_package_raw_inbuf:
 
 
   cell.command = CELL_DATA;
-  cell.topic_command = TOPIC_COMMAND_DATA;
-  cell.topic_id = conn->topic_id;
+  SET_CELL_TOPIC_COMMAND(cell, TOPIC_COMMAND_DATA);
+  SET_CELL_TOPIC_ID(cell, conn->topic_id);
   cell.length += TOPIC_HEADER_SIZE;
 
   if(conn->type == CONN_TYPE_EXIT) {
@@ -752,8 +752,8 @@ int connection_consider_sending_sendme(connection_t *conn, int edge_type) {
 
   memset(&cell, 0, sizeof(cell_t));
   cell.command = CELL_DATA;
-  cell.topic_command = TOPIC_COMMAND_SENDME;
-  cell.topic_id = conn->topic_id;
+  SET_CELL_TOPIC_COMMAND(cell, TOPIC_COMMAND_SENDME);
+  SET_CELL_TOPIC_ID(cell, conn->topic_id);
   cell.length += TOPIC_HEADER_SIZE;
 
   if(edge_type == EDGE_EXIT) { /* we're at an exit */
@@ -860,14 +860,7 @@ cell_pack(char *dest, const cell_t *src)
   *(uint8_t*)(dest+2)  = src->command;
   *(uint8_t*)(dest+3)  = src->length;
   *(uint32_t*)(dest+4) = 0; /* Reserved */
-  if (src->command != CELL_DATA) {
-    memcpy(dest+8, src->payload, CELL_PAYLOAD_SIZE);
-  } else {
-    *(uint8_t*)(dest+8)  = src->topic_command;
-    *(uint8_t*)(dest+9)  = 0;
-    *(uint16_t*)(dest+10) = htons(src->topic_id);
-    memcpy(dest+12, src->payload, CELL_PAYLOAD_SIZE - TOPIC_HEADER_SIZE);
-  }
+  memcpy(dest+8, src->payload, CELL_PAYLOAD_SIZE);
 }
 
 void
@@ -877,14 +870,7 @@ cell_unpack(cell_t *dest, const char *src)
   dest->command = *(uint8_t*)(src+2);
   dest->length  = *(uint8_t*)(src+3);
   dest->seq     = ntohl(*(uint32_t*)(src+4));
-  if (dest->command != CELL_DATA) {
-    memcpy(dest->payload, src+8, CELL_PAYLOAD_SIZE);
-  } else {
-    dest->topic_command = *(uint8_t*)(src+8);
-    /* zero  = *(uint8_t*)(src+9); */
-    dest->topic_id = ntohs(*(uint16_t*)(src+10));
-    memcpy(dest->payload, src+12, CELL_PAYLOAD_SIZE - TOPIC_HEADER_SIZE);
-  }
+  memcpy(dest->payload, src+8, CELL_PAYLOAD_SIZE);
 }
 
 /*

src/or/connection_ap.c

@@ -119,15 +119,18 @@ int ap_handshake_process_socks(connection_t *conn) {
 
 int ap_handshake_send_begin(connection_t *ap_conn, circuit_t *circ) {
   cell_t cell;
+  uint16_t topic_id;
 
   memset(&cell, 0, sizeof(cell_t));
   /* deliver the dest_addr in a data cell */
   cell.command = CELL_DATA;
   cell.aci = circ->n_aci;
-  cell.topic_command = TOPIC_COMMAND_BEGIN;
-  crypto_pseudo_rand(2, (char*)&cell.topic_id);
+  SET_CELL_TOPIC_COMMAND(cell, TOPIC_COMMAND_BEGIN);
+  if (CRYPTO_PSEUDO_RAND_INT(topic_id))
+    return -1;
+  SET_CELL_TOPIC_ID(cell, topic_id);
   /* FIXME check for collisions */
-  ap_conn->topic_id = cell.topic_id;
+  ap_conn->topic_id = topic_id;
 
   snprintf(cell.payload+4, CELL_PAYLOAD_SIZE-4, "%s:%d", ap_conn->dest_addr, ap_conn->dest_port);
   cell.length = strlen(cell.payload+TOPIC_HEADER_SIZE)+1+TOPIC_HEADER_SIZE;

src/or/connection_edge.c

@@ -27,8 +27,8 @@ int connection_edge_process_inbuf(connection_t *conn) {
     memset(&cell, 0, sizeof(cell_t));
     cell.command = CELL_DATA;
     cell.length = TOPIC_HEADER_SIZE;
-    cell.topic_command = TOPIC_COMMAND_END;
-    cell.topic_id = conn->topic_id;
+    SET_CELL_TOPIC_COMMAND(cell, TOPIC_COMMAND_END);
+    SET_CELL_TOPIC_ID(cell, conn->topic_id);
     cell.aci = circ->n_aci;
 
     if (circuit_deliver_data_cell_from_edge(&cell, circ, conn->type) < 0) {
@@ -76,8 +76,8 @@ int connection_edge_send_command(connection_t *conn, circuit_t *circ, int topic_
   else
     cell.aci = circ->p_aci;
   cell.command = CELL_DATA;
-  cell.topic_command = topic_command;
-  cell.topic_id = conn->topic_id;
+  SET_CELL_TOPIC_COMMAND(cell, topic_command);
+  SET_CELL_TOPIC_ID(cell, conn->topic_id);
 
   cell.length = TOPIC_HEADER_SIZE;
   log(LOG_INFO,"connection_edge_send_command(): delivering %d cell %s.", topic_command, conn->type == CONN_TYPE_AP ? "forward" : "backward");
@@ -100,8 +100,8 @@ int connection_edge_process_data_cell(cell_t *cell, circuit_t *circ, int edge_ty
 
   assert(cell && circ);
 
-  topic_command = cell->topic_command;
-  topic_id = cell->topic_id;
+  topic_command = CELL_TOPIC_COMMAND(*cell);
+  topic_id = CELL_TOPIC_ID(*cell);
   log(LOG_DEBUG,"connection_edge_process_data_cell(): command %d topic %d", topic_command, topic_id);
   num_seen++;
   log(LOG_DEBUG,"connection_edge_process_data_cell(): Now seen %d data cells here.", num_seen);

src/or/onion.c

@@ -311,15 +311,14 @@ int chooselen(double cw)
 {
   int len = 2;
   int retval = 0;
-  unsigned char coin;
+  uint8_t coin;
   
   if ((cw < 0) || (cw >= 1)) /* invalid parameter */
     return -1;
   
   while(1)
   {
-    retval = crypto_pseudo_rand(1, &coin);
-    if (retval)
+    if (CRYPTO_PSEUDO_RAND_INT(coin))
       return -1;
     
     if (coin > cw*255) /* don't extend */
@@ -378,7 +377,7 @@ unsigned int *new_route(double cw, routerinfo_t **rarray, int rarray_len, int *r
   oldchoice = rarray_len;
   for(i=0;i<*routelen;i++) {
     log(LOG_DEBUG,"new_route(): Choosing hop %u.",i);
-    if(crypto_pseudo_rand(sizeof(unsigned int),(unsigned char *)&choice)) {
+    if (CRYPTO_PSEUDO_RAND_INT(choice)) {
       free((void *)route);
       return NULL;
     }

src/or/or.h

@@ -198,12 +198,12 @@ typedef struct {
   unsigned char length; /* of payload if data cell, else value of sendme */
   uint32_t seq; /* sequence number */
 
-  /* The following 2 fields are only set when command is CELL_DATA */
-  unsigned char topic_command;
-  uint16_t topic_id;
-
   unsigned char payload[CELL_PAYLOAD_SIZE];
 } cell_t;
+#define CELL_TOPIC_COMMAND(c)         (*(uint8_t*)((c).payload))
+#define SET_CELL_TOPIC_COMMAND(c,cmd) (*(uint8_t*)((c).payload) = (cmd))
+#define CELL_TOPIC_ID(c)              ntohs(*(uint16_t*)((c).payload+2))
+#define SET_CELL_TOPIC_ID(c,id)      (*(uint16_t*)((c).payload+2) = htons(id))
 
 #define SOCKS4_REQUEST_GRANTED          90
 #define SOCKS4_REQUEST_REJECT           91