constexpr static bool is_valid_entry(V v, H const & head, T const &... tail) {
return ((int)head.value() == v)
? true
: (sizeof...(T) > 0)
? is_valid_entry(v, tail...)
: false;
}
/* ***************************************************
* Function: add_to_recv_buffer
* ***************************************************
* This function simply adds a packet (if its a valid packet, defined
* by the next function) to the receiver buffer. It searches the receiver
* buffer for the right place to put the file. The receive buffer is always
* kept in anscending order of sequence numbers.
*/
static void add_to_recv_buffer(context_t *ctx, char* pkt, size_t len)
{
tcp_seq target_seq = ((struct tcphdr *)pkt)->th_seq;
size_t data_len = len - TCP_DATA_START(pkt);
if (!is_valid_entry(ctx,target_seq, data_len)){
our_dprintf("Invalid incoming packet - dropping!\n");
return;
}
struct window* win = &(ctx->rbuffer);
assert((win->end->next==NULL) || !DEBUG);
/* Create a new link list entry */
struct p_entry* new_entry = (struct p_entry*)calloc(1,sizeof(struct p_entry));
new_entry->packet = (char *)calloc(1, len);
memcpy(new_entry->packet, pkt, len);
new_entry->packet_size = len;
tcp_seq curr_seq;
struct p_entry* prev = win->start;
struct p_entry* curr = win->start->next;
bool inserted = false;
/* Search for the right place to add this sequence */
while(curr) {
curr_seq = ((struct tcphdr *)curr->packet)->th_seq;
if (target_seq < curr_seq) {
/* Place found */
inserted = true;
new_entry->next = curr;
prev->next = new_entry;
break;
}
prev = curr;
curr = curr->next;
}
/* Add to the end of the list if not added before */
if (!inserted){
new_entry->next = NULL;
win->end->next = new_entry;
win->end = win->end->next;
}
win->num_entries+=1;
our_dprintf("Added Recv: %d to receive buffer\n", ((struct tcphdr*)pkt)->th_seq);
}
