/**
* first fragment for given address is detected - setup
*/
ip_frag_desc_t *ip_frag_manager::new_frag_desc(ip_frag_key_t &key)
{
ip_frag_desc_t *desc = NULL;
struct ip_frag_hole_desc *hole = NULL;
hole = alloc_hole_desc();
if (!hole){
frag_dbg("NULL hole");
return NULL;
}
hole->first = IP_FRAG_NINF;
hole->last = IP_FRAG_INF;
desc = alloc_frag_desc();
if (!desc) {
frag_dbg("NULL desc");
free_hole_desc(hole);
return NULL;
}
desc->ttl = IP_FRAG_TTL;
desc->frag_list = 0;
desc->hole_list = hole;
desc->frag_counter = m_frag_counter;
m_frags[key] = desc;
return desc;
}
ip_frag_manager::ip_frag_manager() : lock_spin("ip_frag_manager")
{
frag_dbg("");
m_frag_counter = 0;
int i;
frag_dbg("NOTE: ip frag periodic timer is disabled until HW supports ip frag offload");
// g_p_event_handler_manager->register_timer_event(IP_FRAG_CLEANUP_INT, this, PERIODIC_TIMER, 0);
frag_dbg("Created new IPFRAG MANAGER instance");
/* allocate hole list */
desc_base = new ip_frag_desc_t [IP_FRAG_MAX_DESC];
BULLSEYE_EXCLUDE_BLOCK_START
if (!desc_base) {
frag_dbg("Failed to allocate descriptor");
free_frag_resources();
throw_vma_exception("Failed to allocate descriptor");
}
hole_base = new ip_frag_hole_desc [IP_FRAG_MAX_HOLES];
if (!hole_base) {
frag_dbg("Failed to allocate hole descriptor");
free_frag_resources();
throw_vma_exception("Failed to allocate hole descriptor");
}
BULLSEYE_EXCLUDE_BLOCK_END
for (i = 0; i < IP_FRAG_MAX_DESC; i++) {
free_frag_desc(&desc_base[i]);
}
for (i = 0; i < IP_FRAG_MAX_HOLES; i++) {
free_hole_desc(&hole_base[i]);
}
}
void ip_frag_manager::free_frag_resources(void)
{
ip_frags_list_t::iterator i;
ip_frag_desc_t *desc;
frag_dbg("NOTE: ip frag periodic timer is disabled until HW supports ip frag offload");
// g_p_event_handler_manager->unregister_timer_event(this, NULL);
lock();
while (m_frags.size() > 0) {
i = m_frags.begin();
desc = i->second;
destroy_frag_desc(desc);
free_frag_desc(desc);
m_frags.erase(i);
}
owner_desc_map_t temp_buff_map = m_return_descs;
m_return_descs.clear();
unlock();
// Must call cq_mgr outside the lock to avoid ABBA deadlock
return_buffers_to_owners(temp_buff_map);
delete [] desc_base;
delete [] hole_base;
frag_dbg("Deleted IPFRAG MANAGER instance");
}
static void pico_ipv6_frag_timer_on(void)
{
ipv6_fragments_timer = pico_timer_add(PICO_IPV6_FRAG_TIMEOUT, pico_frag_expire, &ipv6_fragments);
if (!ipv6_fragments_timer) {
frag_dbg("FRAG: Failed to start IPv6 expiration timer\n");
pico_fragments_empty_tree(&ipv6_fragments);
}
}
void ip_frag_manager::handle_timer_expired(void* user_data)
{
NOT_IN_USE(user_data);
ip_frags_list_t::iterator iter, iter_temp;
ip_frag_desc_t *desc;
uint64_t delta =0;
lock();
if (m_frag_counter > IP_FRAG_SPACE) {
delta = m_frag_counter - IP_FRAG_SPACE;
m_frag_counter -= delta;
}
frag_dbg("calling handle_timer_expired, m_frag_counter=%ld, delta=%ld", m_frag_counter, delta);
PRINT_STATISTICS();
iter = m_frags.begin();
while (iter != m_frags.end()) {
desc = iter->second;
desc->frag_counter -= delta;
if (desc->frag_counter<0 || (desc->ttl <= 0)) { //discard this packet
frag_dbg("expiring packet fragments desc=%p (frag_counter=%d, ttl=%d)", desc, desc->frag_counter, desc->ttl);
destroy_frag_desc(desc);
free_frag_desc(desc);
iter_temp = iter++;
m_frags.erase(iter_temp);
}
else {
iter++;
}
--desc->ttl;
}
owner_desc_map_t temp_buff_map = m_return_descs;
m_return_descs.clear();
PRINT_STATISTICS();
unlock();
// Must call cq_mgr outside the lock to avoid ABBA deadlock
return_buffers_to_owners(temp_buff_map);
}
/**
* Complexity of the algorithm:
* O(1) if packets are coming in order or reverse order
* O(n^2) for random fragments, where n is number of fragments
* returns: 0 if finished OK (if the packet is complete - put it in ret)
* -1 if finished not OK and this packet needs to be droped
*/
int ip_frag_manager::add_frag(iphdr *hdr, mem_buf_desc_t *frag, mem_buf_desc_t **ret)
{
ip_frag_key_t key;
ip_frags_list_t::iterator i;
ip_frag_desc_t *desc;
struct ip_frag_hole_desc *phole, *phole_prev;
struct ip_frag_hole_desc *new_hole;
uint16_t frag_off, frag_first, frag_last;
bool more_frags;
assert(hdr);
assert(frag);
key.ip_id = hdr->id; //id is in network order!
key.src_ip = hdr->saddr;
key.dst_ip = hdr->daddr;
key.ipproto = hdr->protocol;
frag_dbg("Fragment: %d.%d.%d.%d->%d.%d.%d.%d id=%x size=%d",
NIPQUAD(key.src_ip),
NIPQUAD(key.dst_ip),
(int)key.ip_id, (int)ntohs(hdr->tot_len));
#ifdef IP_FRAG_DEBUG
if (debug_drop_every_n_pkt && ((++debug_drop_index) % debug_drop_every_n_pkt == 0)) {
frag_dbg("XXX debug force dropped XXX");
return -1;
}
#endif
lock();
MEMBUF_DEBUG_REF_INC(frag);
PRINT_STATISTICS();
frag_off = ntohs(hdr->frag_off);
more_frags = frag_off & MORE_FRAGMENTS_FLAG;
frag_first = (frag_off & FRAGMENT_OFFSET) * 8;
frag_last = frag_first + ntohs(hdr->tot_len) - (hdr->ihl<<2) - 1; // frag starts from 0!!!
frag_dbg("> fragment: %d-%d, %s more frags", frag_first, frag_last, more_frags?"pending":"no");
m_frag_counter++;
i = m_frags.find(key);
if (i == m_frags.end()) {
/* new fragment */
frag_dbg("> new fragmented packet");
desc = new_frag_desc(key);
}
else {
desc = i->second;
if ((m_frag_counter - desc->frag_counter) > IP_FRAG_SPACE) {
// discard this packet
frag_dbg("expiring packet fragments id=%x", i->first);
destroy_frag_desc(desc);
free_frag_desc(desc);
m_frags.erase(i);
i = m_frags.end();
// Add new fregment
frag_dbg("> new fragmented packet");
desc = new_frag_desc(key);
}
else {
frag_dbg("> old fragmented packet");
}
}
if (desc==NULL) {
MEMBUF_DEBUG_REF_DEC(frag);
PRINT_STATISTICS();
unlock();
return -1;
}
//desc->last_frag_counter = m_frag_counter;
/* 8 step reassembly algorithm as described in RFC 815 */
//step 1
phole_prev = 0; phole = desc->hole_list;
while (phole) {
//step 2 and step 3
if (frag_first >= phole->first && frag_last <= phole->last) {
break;
}
phole_prev = phole;
phole = phole->next;
}
if (!phole) { // the right hole wasn't found
MEMBUF_DEBUG_REF_DEC(frag);
PRINT_STATISTICS();
unlock();
return -1;
}
frag_dbg("> found hole: %d-%d", phole->first, phole->last);
// step 4 - remove hole from list
if (phole_prev)
phole_prev->next = phole->next;
else
desc->hole_list = phole->next;
// step 5
if (frag_first > phole->first) {
new_hole = alloc_hole_desc();
if (!new_hole) {
free_hole_desc(phole); // phole was removed from the list in step 4!
MEMBUF_DEBUG_REF_DEC(frag);
PRINT_STATISTICS();
unlock();
return -1;
}
new_hole->first = phole->first;
new_hole->last = frag_first-1;
new_hole->data_first = phole->data_first;
new_hole->data_last = frag;
new_hole->next = phole->next;
if (phole_prev)
phole_prev->next = new_hole;
else
desc->hole_list = new_hole;
phole_prev = new_hole;
}
//step 6
if (frag_last < phole->last && more_frags) {
new_hole = alloc_hole_desc();
if (!new_hole) {
free_hole_desc(phole); // phole was removed from the list in step 4!
MEMBUF_DEBUG_REF_DEC(frag);
PRINT_STATISTICS();
unlock();
return -1;
}
new_hole->first = frag_last + 1;
new_hole->last = phole->last;
new_hole->data_first = frag;
new_hole->data_last = phole->data_last;
new_hole->next = phole->next;
if (phole_prev)
phole_prev->next = new_hole;
else
desc->hole_list = new_hole;
}
// link frag
if (phole->data_first)
phole->data_first->p_next_desc = frag;
else
desc->frag_list = frag;
frag->p_next_desc = phole->data_last;
free_hole_desc(phole);
if (!desc->hole_list) {
//step 8 - datagram assembly completed
if (i == m_frags.end())
i = m_frags.find(key);
if (i == m_frags.end()){
MEMBUF_DEBUG_REF_DEC(frag);
frag_panic("frag desc lost from map???");
//coverity unreachable
/*unlock();
return -1;*/
}
MEMBUF_DEBUG_REF_DEC(desc->frag_list);
m_frags.erase(i);
*ret = desc->frag_list;
free_frag_desc(desc);
frag_dbg("> PACKET ASSEMBLED");
PRINT_STATISTICS();
unlock();
return 0;
}
frag_dbg("> need more packets");
*ret = NULL;
PRINT_STATISTICS();
unlock();
return 0;
}
void ip_frag_manager::print_statistics()
{
frag_dbg("free desc=%d, free holes=%d, map size=%d, frags=%d", desc_free_list_count, hole_free_list_count, m_frags.size(), g_ip_frag_count_check);
}