Пример #1
0
static int proto_udp_process(void *proto_priv, struct packet *p, struct proto_process_stack *stack, unsigned int stack_index) {

	struct proto_process_stack *s = &stack[stack_index];

	if (sizeof(struct udphdr) > s->plen)
		return PROTO_INVALID;

	struct udphdr *hdr = s->pload;

	uint16_t ulen = ntohs(hdr->uh_ulen);
	uint16_t sport = ntohs(hdr->uh_sport);
	uint16_t dport = ntohs(hdr->uh_dport);

	if (ulen > s->plen)
		return PROTO_INVALID;

	PTYPE_UINT16_SETVAL(s->pkt_info->fields_value[proto_udp_field_sport], sport);
	PTYPE_UINT16_SETVAL(s->pkt_info->fields_value[proto_udp_field_dport], dport);

	if (conntrack_get(stack, stack_index) != POM_OK)
		return POM_ERR;

	int res = POM_ERR;
	struct proto_process_stack *s_next = &stack[stack_index + 1];

	if (s->ce->children) {
		res = conntrack_delayed_cleanup(s->ce, 0, p->ts);
		s_next->proto = s->ce->children->ce->proto;
	} else {
		uint32_t *conntrack_timeout = PTYPE_UINT32_GETVAL(param_conntrack_timeout);
		res = conntrack_delayed_cleanup(s->ce, *conntrack_timeout, p->ts);
	}

	conntrack_unlock(s->ce);

	s_next->pload = s->pload + sizeof(struct udphdr);
	s_next->plen = ulen - sizeof(struct udphdr);

	if (!s_next->proto) {

		if (dport == 53 || sport == 53)
			s_next->proto = proto_dns;

		if (dport == 69 || sport == 69)
			s_next->proto = proto_tftp;
	}

	return res;

}
Пример #2
0
static void stream_end_process_packet(struct stream *stream) {

	conntrack_delayed_cleanup(stream->ce, stream->timeout, stream->last_ts);

	pom_mutex_unlock(&stream->lock);
	pom_mutex_lock(&stream->wait_lock);
	if (stream->wait_list_head) {
		debug_stream("thread %p, entry %p : signaling thread %p", pthread_self(), stream, stream->wait_list_head->thread);
		pthread_cond_broadcast(&stream->wait_list_head->cond);
	}
	pom_mutex_unlock(&stream->wait_lock);
}
Пример #3
0
int stream_cleanup(struct stream *stream) {


	if (stream->wait_list_head) {
		pomlog(POMLOG_ERR "Internal error, cleaning up stream while packets still present!");
		return POM_ERR;
	}

	while (stream->head[0] || stream->head[1]) {
		if (stream_force_dequeue(stream) == POM_ERR) {
			pomlog(POMLOG_ERR "Error while processing remaining packets in the stream");
			break;
		}
	}

	conntrack_delayed_cleanup(stream->ce, 0, stream->last_ts);

	int res = pthread_mutex_destroy(&stream->lock);
	if (res){
		pomlog(POMLOG_ERR "Error while destroying stream lock : %s", pom_strerror(res));
	}

	res = pthread_mutex_destroy(&stream->wait_lock);
	if (res){
		pomlog(POMLOG_ERR "Error while destroying stream wait lock : %s", pom_strerror(res));
	}

	while (stream->wait_list_unused) {
		struct stream_thread_wait *tmp = stream->wait_list_unused;
		stream->wait_list_unused = tmp->next;
		if (pthread_cond_destroy(&tmp->cond))
			pomlog(POMLOG_WARN "Error while destroying list condition");
		free(tmp);
	}
	
	free(stream);

	debug_stream("thread %p, entry %p, released", pthread_self(), stream);

	return POM_OK;
}
Пример #4
0
static int proto_eap_process(void *proto_priv, struct packet *p, struct proto_process_stack *stack, unsigned int stack_index) {

	struct proto_process_stack *s = &stack[stack_index];

	if (sizeof(struct eap_header) > s->plen)
		return PROTO_INVALID;

	struct proto_eap_priv *priv = proto_priv;

	struct eap_header *hdr = s->pload;

	PTYPE_UINT8_SETVAL(s->pkt_info->fields_value[proto_eap_field_code], hdr->code);
	PTYPE_UINT8_SETVAL(s->pkt_info->fields_value[proto_eap_field_identifier], hdr->identifier);

	
	if (hdr->code < 1 || hdr->code > 4)
		return PROTO_INVALID;

	uint16_t len = ntohs(hdr->length);

	if (len > s->plen)
		return PROTO_INVALID;

	// Keep only the payload lenght
	len -= sizeof(struct eap_header);
	
	if (conntrack_get(stack, stack_index) != POM_OK)
		return PROTO_ERR;

	if (conntrack_delayed_cleanup(s->ce, *PTYPE_UINT32_GETVAL(priv->p_timeout), p->ts) != POM_OK) {
		conntrack_unlock(s->ce);
		return PROTO_ERR;
	}
	conntrack_unlock(s->ce);

	if (hdr->code == 3 || hdr->code == 4) {
		// Content length is 0 for success and failure
		if (len != 4)
			return PROTO_INVALID;
		len = 0;

		if (!event_has_listener(priv->evt_success_failure))
			return PROTO_OK;

		struct event *evt = event_alloc(priv->evt_success_failure);
		if (!evt)
			return PROTO_ERR;
		struct data *evt_data = event_get_data(evt);
		PTYPE_UINT8_SETVAL(evt_data[evt_eap_common_identifier].value, hdr->identifier);
		data_set(evt_data[evt_eap_common_identifier]);
		PTYPE_BOOL_SETVAL(evt_data[evt_eap_success_failure_success].value, (hdr->code == 3 ? 1 : 0));
		data_set(evt_data[evt_eap_success_failure_success]);

		return event_process(evt, stack, stack_index, p->ts);
	}

	// At this point, code is either 1 or 2 (request/response)

	void *pload = s->pload + sizeof(struct eap_header);

	uint8_t type = 0;

	// There is at least 1 byte of data for request/response
	if (len < 1)
		return PROTO_INVALID;
	len--;

	type = *(uint8_t*)pload;
	pload++;

	struct event *evt = NULL;
	struct data *evt_data = NULL;
	
	switch (type) {
		case 1: // Identity
			
			if (!event_has_listener(priv->evt_identity))
				break;

			evt = event_alloc(priv->evt_identity);
			if (!evt)
				return PROTO_ERR;
			if (len) {
				evt_data = event_get_data(evt);
				PTYPE_STRING_SETVAL_N(evt_data[evt_eap_identity_identity].value, pload, len);
				data_set(evt_data[evt_eap_identity_identity]);
			}

			break;

		case 4: // MD5-Challenge
		
			if (!event_has_listener(priv->evt_md5_challenge))
				break;

			if (len < 17)
				return PROTO_INVALID;

			uint8_t value_size = *(uint8_t*)pload;
			if (value_size != 16)
				return PROTO_INVALID;

			pload++;
			len--;

			evt = event_alloc(priv->evt_md5_challenge);
			if (!evt)
				return PROTO_ERR;
			evt_data = event_get_data(evt);

			PTYPE_BYTES_SETLEN(evt_data[evt_eap_md5_challenge_value].value, 16);
			PTYPE_BYTES_SETVAL(evt_data[evt_eap_md5_challenge_value].value, pload);
			data_set(evt_data[evt_eap_md5_challenge_value]);
			
			if (len > 16) {
				PTYPE_STRING_SETVAL_N(evt_data[evt_eap_md5_challenge_name].value, pload + 16, len - 16);
				data_set(evt_data[evt_eap_md5_challenge_name]);
			}
			break;
	}
	
	if (evt) {
		if (!evt_data)
			evt_data = event_get_data(evt);
		PTYPE_UINT8_SETVAL(evt_data[evt_eap_common_identifier].value, hdr->identifier);
		data_set(evt_data[evt_eap_common_identifier]);
		PTYPE_UINT8_SETVAL(evt_data[evt_eap_common_code].value, hdr->code);
		data_set(evt_data[evt_eap_common_code]);

		if (event_process(evt, stack, stack_index, p->ts) != POM_OK)
			return PROTO_ERR;
	}


	return PROTO_OK;

}
Пример #5
0
static int proto_ipv4_process(void *proto_priv, struct packet *p, struct proto_process_stack *stack, unsigned int stack_index) {

	struct proto_process_stack *s = &stack[stack_index];
	struct proto_process_stack *s_next = &stack[stack_index + 1];

	struct ip* hdr = s->pload;

	unsigned int hdr_len = hdr->ip_hl * 4;

	if (s->plen < sizeof(struct ip) || // length smaller than header
		hdr->ip_hl < 5 || // ip header < 5 bytes
		ntohs(hdr->ip_len) < hdr_len || // datagram size < ip header length
		ntohs(hdr->ip_len) > s->plen) { // datagram size > given size
		return PROTO_INVALID;
	}


	PTYPE_IPV4_SETADDR(s->pkt_info->fields_value[proto_ipv4_field_src], hdr->ip_src);
	PTYPE_IPV4_SETADDR(s->pkt_info->fields_value[proto_ipv4_field_dst], hdr->ip_dst);
	PTYPE_UINT8_SETVAL(s->pkt_info->fields_value[proto_ipv4_field_tos], hdr->ip_tos);
	PTYPE_UINT8_SETVAL(s->pkt_info->fields_value[proto_ipv4_field_ttl], hdr->ip_ttl);

	// Handle conntrack stuff
	if (conntrack_get(stack, stack_index) != POM_OK)
		return PROTO_ERR;


	s_next->pload = s->pload + hdr_len;
	s_next->plen = ntohs(hdr->ip_len) - hdr_len;

	s_next->proto = proto_get_by_number(s->proto, hdr->ip_p);


	int res = POM_ERR;
	if (s->ce->children) {
		res = conntrack_delayed_cleanup(s->ce, 0, p->ts);
	} else {
		uint32_t *conntrack_timeout = PTYPE_UINT32_GETVAL(param_conntrack_timeout);
		res = conntrack_delayed_cleanup(s->ce, *conntrack_timeout, p->ts);
	}
	if (res == POM_ERR) {
		conntrack_unlock(s->ce);
		return PROTO_ERR;
	}

	uint16_t frag_off = ntohs(hdr->ip_off);

	// Check if packet is fragmented and need more handling

	if (frag_off & IP_DONT_FRAG) {
		conntrack_unlock(s->ce);
		return PROTO_OK; // Nothing to do
	}

	if (!(frag_off & IP_MORE_FRAG) && !(frag_off & IP_OFFSET_MASK)) {
		conntrack_unlock(s->ce);
		return PROTO_OK; // Nothing to do, full packet
	}

	uint16_t offset = (frag_off & IP_OFFSET_MASK) << 3;
	size_t frag_size = ntohs(hdr->ip_len) - (hdr->ip_hl * 4);

	// Ignore invalid fragments
	if (frag_size > 0xFFFF) {
		conntrack_unlock(s->ce);
		return PROTO_INVALID;
	}

	if (frag_size > s->plen + hdr_len) {
		conntrack_unlock(s->ce);
		return PROTO_INVALID;
	}

	// Account for one more fragment
	registry_perf_inc(perf_frags, 1);

	struct proto_ipv4_fragment *tmp = s->ce->priv;

	// Let's find the right buffer
	for (; tmp && tmp->id != hdr->ip_id; tmp = tmp->next);

	if (!tmp) {
		// Buffer not found, create it
		tmp = malloc(sizeof(struct proto_ipv4_fragment));
		if (!tmp) {
			pom_oom(sizeof(struct proto_ipv4_fragment));
			conntrack_unlock(s->ce);
			return PROTO_ERR;
		}
		memset(tmp, 0, sizeof(struct proto_ipv4_fragment));

		tmp->t = conntrack_timer_alloc(s->ce, proto_ipv4_fragment_cleanup, tmp);
		if (!tmp->t) {
			conntrack_unlock(s->ce);
			free(tmp);
			return PROTO_ERR;
		}
		
		tmp->id = hdr->ip_id;

		if (!s_next->proto) {
			// Set processed flag so no attempt to process this will be done
			tmp->flags |= PROTO_IPV4_FLAG_PROCESSED;
			conntrack_unlock(s->ce);
			conntrack_timer_cleanup(tmp->t);
			free(tmp);
			return PROTO_STOP;
		}

		tmp->multipart = packet_multipart_alloc(s_next->proto, 0);
		if (!tmp->multipart) {
			conntrack_unlock(s->ce);
			conntrack_timer_cleanup(tmp->t);
			free(tmp);
			return PROTO_ERR;
		}

		tmp->next = s->ce->priv;
		if (tmp->next)
			tmp->next->prev = tmp;
		s->ce->priv = tmp;
	}

	// Fragment was already handled
	if (tmp->flags & PROTO_IPV4_FLAG_PROCESSED) {
		conntrack_unlock(s->ce);
		registry_perf_inc(perf_frags_dropped, 1);
		return PROTO_STOP;
	}
	
	// Add the fragment
	if (packet_multipart_add_packet(tmp->multipart, p, offset, frag_size, (s->pload - (void*)p->buff) + (hdr->ip_hl * 4)) != POM_OK) {
		conntrack_unlock(s->ce);
		packet_multipart_cleanup(tmp->multipart);
		conntrack_timer_cleanup(tmp->t);
		free(tmp);
		return PROTO_ERR;
	}
	tmp->count++;

	// Schedule the timeout for the fragment
	uint32_t *frag_timeout = PTYPE_UINT32_GETVAL(param_frag_timeout);
	conntrack_timer_queue(tmp->t, *frag_timeout, p->ts);


	if (!(frag_off & IP_MORE_FRAG))
		tmp->flags |= PROTO_IPV4_FLAG_GOT_LAST;

	if ((tmp->flags & PROTO_IPV4_FLAG_GOT_LAST) && !tmp->multipart->gaps)
		tmp->flags |= PROTO_IPV4_FLAG_PROCESSED;


	conntrack_unlock(s->ce);
	
	if ((tmp->flags & PROTO_IPV4_FLAG_PROCESSED)) {
		int res = packet_multipart_process(tmp->multipart, stack, stack_index + 1);
		tmp->multipart = NULL; // Multipart will be cleared automatically
		if (res == PROTO_ERR) {
			return PROTO_ERR;
		} else if (res == PROTO_INVALID) {
			registry_perf_inc(perf_frags_dropped, tmp->count);
		} else {
			registry_perf_inc(perf_reassembled_pkts, 1);
		}
	}

	return PROTO_STOP; // Stop processing the packet

}
Пример #6
0
static int proto_ppp_pap_process(void *proto_priv, struct packet *p, struct proto_process_stack *stack, unsigned int stack_index) {

	struct proto_process_stack *s = &stack[stack_index];

	if (sizeof(struct ppp_pap_header) > s->plen)
		return PROTO_INVALID;

	struct ppp_pap_header *pchdr = s->pload;
	size_t len = ntohs(pchdr->length);

	if (len > s->plen)
		return PROTO_INVALID;

	// Keep only the payload len
	len -= sizeof(struct ppp_pap_header);

	PTYPE_UINT8_SETVAL(s->pkt_info->fields_value[proto_ppp_pap_field_code], pchdr->code);
	PTYPE_UINT8_SETVAL(s->pkt_info->fields_value[proto_ppp_pap_field_identifier], pchdr->identifier);

	struct proto_ppp_pap_priv *priv = proto_priv;

	if (conntrack_get(stack, stack_index) != POM_OK)
		return PROTO_ERR;
	if (conntrack_delayed_cleanup(s->ce, *PTYPE_UINT32_GETVAL(priv->p_auth_timeout), p->ts) != POM_OK) {
		conntrack_unlock(s->ce);
		return PROTO_ERR;
	}
	
	conntrack_unlock(s->ce);

	if (pchdr->code == 1 && event_has_listener(priv->evt_request)) {

		if (len < 4)
			return PROTO_INVALID;

		uint8_t *peer_id_len = s->pload + sizeof(struct ppp_pap_header);
		if (*peer_id_len > len - 2)
			return PROTO_INVALID;

		len -= (*peer_id_len + 1);
		uint8_t *pwd_len = peer_id_len + *peer_id_len + 1;
		if (*pwd_len > len - 1)
			return PROTO_INVALID;


		// Process the challenge/response event
		struct event *evt = event_alloc(priv->evt_request);
		if (!evt)
			return PROTO_ERR;

		struct data *evt_data = event_get_data(evt);
		PTYPE_UINT8_SETVAL(evt_data[evt_ppp_pap_request_code].value, pchdr->code);
		data_set(evt_data[evt_ppp_pap_request_code]);
		PTYPE_UINT8_SETVAL(evt_data[evt_ppp_pap_request_identifier].value, pchdr->identifier);
		data_set(evt_data[evt_ppp_pap_request_identifier]);

	
		PTYPE_STRING_SETVAL_N(evt_data[evt_ppp_pap_request_peer_id].value, (char *)peer_id_len + 1, *peer_id_len);
		data_set(evt_data[evt_ppp_pap_request_peer_id]);

		PTYPE_STRING_SETVAL_N(evt_data[evt_ppp_pap_request_password].value, (char *)pwd_len + 1, *pwd_len);
		data_set(evt_data[evt_ppp_pap_request_password]);

		if (event_process(evt, stack, stack_index, p->ts) != POM_OK)
			return PROTO_ERR;

	}

	if ((pchdr->code == 2 || pchdr->code == 3) && event_has_listener(priv->evt_ack_nack)) {
		
		struct event *evt = event_alloc(priv->evt_ack_nack);
		if (!evt)
			return PROTO_ERR;

		struct data *evt_data = event_get_data(evt);
		PTYPE_UINT8_SETVAL(evt_data[evt_ppp_pap_ack_nack_code].value, pchdr->code);
		data_set(evt_data[evt_ppp_pap_ack_nack_code]);
		PTYPE_UINT8_SETVAL(evt_data[evt_ppp_pap_ack_nack_identifier].value, pchdr->identifier);
		data_set(evt_data[evt_ppp_pap_ack_nack_identifier]);

		uint8_t *msg_len = s->pload + sizeof(struct ppp_pap_header);
		if (*msg_len > len - 1)
			return PROTO_INVALID;

		PTYPE_STRING_SETVAL_N(evt_data[evt_ppp_pap_ack_nack_message].value, (char *)msg_len + 1, *msg_len);
		data_set(evt_data[evt_ppp_pap_ack_nack_message]);

		if (event_process(evt, stack, stack_index, p->ts) != POM_OK)
			return PROTO_ERR;

	}

	return PROTO_OK;

}
Пример #7
0
int conntrack_cleanup(struct conntrack_tables *ct, uint32_t hash, struct conntrack_entry *ce) {

	// Remove the conntrack from the conntrack table
	pom_mutex_lock(&ct->locks[hash]);

	// Try to find the conntrack in the list
	struct conntrack_list *lst = NULL;

	for (lst = ct->table[hash]; lst && lst->ce != ce; lst = lst->next);

	if (!lst) {
		pom_mutex_unlock(&ct->locks[hash]);
		pomlog(POMLOG_ERR "Trying to cleanup a non existing conntrack : %p", ce);
		return POM_OK;
	}

	conntrack_lock(ce);
	if (ce->refcount) {
		debug_conntrack(POMLOG_ERR "Conntrack %p is still being referenced : %u !", ce, ce->refcount);
		conntrack_delayed_cleanup(ce, 1, core_get_clock_last());
		conntrack_unlock(ce);
		pom_mutex_unlock(&ct->locks[hash]);
		return POM_OK;
	}


	if (lst->prev)
		lst->prev->next = lst->next;
	else
		ct->table[hash] = lst->next;

	if (lst->next)
		lst->next->prev = lst->prev;

	free(lst);

	pom_mutex_unlock(&ct->locks[hash]);

	if (ce->cleanup_timer && ce->cleanup_timer != (void *) -1) {
		conntrack_timer_cleanup(ce->cleanup_timer);
		ce->cleanup_timer = (void *) -1; // Mark that the conntrack is being cleaned up
	}

	// Once the conntrack is removed from the hash table, it will not be referenced ever again
	conntrack_unlock(ce);

	if (ce->parent) {
		debug_conntrack("Cleaning up conntrack %p, with parent %p", ce, ce->parent->ce);
	} else {
		debug_conntrack("Cleaning up conntrack %p, with no parent", ce);
	}

	
	if (ce->parent) {
		// Remove the child from the parent
		
		// Make sure the parent still exists
		uint32_t hash = ce->parent->hash;
		pom_mutex_lock(&ce->parent->ct->locks[hash]);
		
		for (lst = ce->parent->ct->table[hash]; lst && lst->ce != ce->parent->ce; lst = lst->next);

		if (lst) {

			conntrack_lock(ce->parent->ce);
			struct conntrack_node_list *tmp = ce->parent->ce->children;

			for (; tmp && tmp->ce != ce; tmp = tmp->next);

			if (tmp) {
				if (tmp->prev)
					tmp->prev->next = tmp->next;
				else
					ce->parent->ce->children = tmp->next;

				if (tmp->next)
					tmp->next->prev = tmp->prev;

				free(tmp);
			} else {
				pomlog(POMLOG_WARN "Conntrack %s not found in parent's %s children list", ce, ce->parent->ce);
			}

			if (!ce->parent->ce->children) // Parent has no child anymore, clean it up after some time
				conntrack_delayed_cleanup(ce->parent->ce, CONNTRACK_CHILDLESS_TIMEOUT, core_get_clock_last());

			conntrack_unlock(ce->parent->ce);
		} else {
			debug_conntrack("Parent conntrack %p not found while cleaning child %p !", ce->parent->ce, ce);
		}

		pom_mutex_unlock(&ce->parent->ct->locks[hash]);

		free(ce->parent);
	}

	if (ce->session)
		conntrack_session_refcount_dec(ce->session);

	// Cleanup private stuff from the conntrack
	if (ce->priv && ce->proto->info->ct_info->cleanup_handler) {
		if (ce->proto->info->ct_info->cleanup_handler(ce->priv) != POM_OK)
			pomlog(POMLOG_WARN "Unable to free the private memory of a conntrack");
	}

	// Cleanup the priv_list
	struct conntrack_priv_list *priv_lst = ce->priv_list;
	while (priv_lst) {
		if (priv_lst->cleanup) {
			if (priv_lst->cleanup(priv_lst->obj, priv_lst->priv) != POM_OK)
				pomlog(POMLOG_WARN "Error while cleaning up private objects in conntrack_entry");
		}
		ce->priv_list = priv_lst->next;
		free(priv_lst);
		priv_lst = ce->priv_list;

	}


	// Cleanup the children
	while (ce->children) {
		struct conntrack_node_list *child = ce->children;
		ce->children = child->next;

		if (conntrack_cleanup(child->ct, child->hash, child->ce) != POM_OK) 
			return POM_ERR;

		free(child);
	}

	
	if (ce->fwd_value)
		ptype_cleanup(ce->fwd_value);
	if (ce->rev_value)
		ptype_cleanup(ce->rev_value);

	pthread_mutex_destroy(&ce->lock);

	registry_perf_dec(ce->proto->perf_conn_cur, 1);

	free(ce);

	return POM_OK;
}
Пример #8
0
static int proto_tftp_process(void *proto_priv, struct packet *p, struct proto_process_stack *stack, unsigned int stack_index) {

	struct proto_process_stack *s = &stack[stack_index];
	struct proto_process_stack *s_prev = &stack[stack_index - 1];
	struct proto_process_stack *s_next = &stack[stack_index + 1];

	if (conntrack_get_unique_from_parent(stack, stack_index) != POM_OK) {
		pomlog(POMLOG_ERR "Could not get a conntrack entry");
		return PROTO_ERR;
	}

	struct proto_tftp_conntrack_priv *priv = s->ce->priv;
	if (!priv) {
		priv = malloc(sizeof(struct proto_tftp_conntrack_priv));
		if (!priv) {
			pom_oom(sizeof(struct proto_tftp_conntrack_priv));
			conntrack_unlock(s->ce);
			return POM_ERR;
		}
		memset(priv, 0, sizeof(struct proto_tftp_conntrack_priv));

		s->ce->priv = priv;
	}

	if (priv->flags & PROTO_TFTP_CONN_INVALID) {
		conntrack_unlock(s->ce);
		return PROTO_INVALID;
	}

	void *pload = s->pload;
	uint32_t plen = s->plen;


	// proto_tftp only process up to the opcode field
	// afterwards, it's up to the analyzer to parse the rest

	uint16_t opcode = ntohs(*((uint16_t*)pload));
	PTYPE_UINT16_SETVAL(s->pkt_info->fields_value[proto_tftp_field_opcode], opcode);
	pload += sizeof(uint16_t);
	plen -= sizeof(uint16_t);

	s_next->pload = pload;
	s_next->plen = plen;

	switch (opcode) {
		case tftp_rrq:
		case tftp_wrq: {

			// Find the filename
			char *filename = pload;
			char *mode = memchr(filename, 0, plen - 1);
			if (!mode) {
				priv->flags |= PROTO_TFTP_CONN_INVALID;
				conntrack_unlock(s->ce);
				debug_tftp("End of filename not found in read/write request");
				return PROTO_INVALID;
			}
			mode++;
			ssize_t filename_len = mode - filename;

			char *end = memchr(mode, 0, plen - filename_len);
			if (!end) {
				priv->flags |= PROTO_TFTP_CONN_INVALID;
				conntrack_unlock(s->ce);
				debug_tftp("End of mode not found in read/write request");
				return PROTO_INVALID;
			}
			debug_tftp("Got read/write request for filename \"%s\" with mode \"%s\"", filename, mode);

			struct conntrack_session *session = conntrack_session_get(s->ce);
			if (!session) {
				conntrack_unlock(s->ce);
				return POM_ERR;
			}

			// We don't need to do anything with the session
			conntrack_session_unlock(session);

			struct proto_expectation *expt = proto_expectation_alloc_from_conntrack(s_prev->ce, proto_tftp, NULL);

			if (!expt) {
				conntrack_unlock(s->ce);
				return PROTO_ERR;
			}

			proto_expectation_set_field(expt, -1, NULL, POM_DIR_REV);

			if (proto_expectation_add(expt, session, PROTO_TFTP_EXPT_TIMER, p->ts) != POM_OK) {
				conntrack_unlock(s->ce);
				proto_expectation_cleanup(expt);
				return PROTO_ERR;
			}

			break;
		}
		case tftp_data: {
			if (plen < 2) {
				priv->flags |= PROTO_TFTP_CONN_INVALID;
				conntrack_unlock(s->ce);
				return PROTO_INVALID;
			}
			uint16_t block_id = ntohs(*((uint16_t*)(pload)));

			int set_start_seq = 0;
			if (!priv->stream) {
				priv->stream = stream_alloc(PROTO_TFTP_STREAM_BUFF, s->ce, 0, proto_tftp_process_payload);
				if (!priv->stream) {
					conntrack_unlock(s->ce);
					return PROTO_ERR;
				}
				stream_set_timeout(priv->stream, PROTO_TFTP_PKT_TIMER);
				set_start_seq = 1;
			}

			conntrack_unlock(s->ce);
			
			if (set_start_seq)
				stream_set_start_seq(priv->stream, s->direction, PROTO_TFTP_BLK_SIZE + 2);
			int res = stream_process_packet(priv->stream, p, stack, stack_index + 1, block_id * (PROTO_TFTP_BLK_SIZE + 2), 0);

			return (res == PROTO_OK ? PROTO_STOP : res);
		}

		case tftp_ack:
			// Nothing to do
			break;

		case tftp_error:
			// An error occured, cleanup this conntrack soon
			conntrack_delayed_cleanup(s->ce, 1, p->ts);
			break;

		default:
			priv->flags |= PROTO_TFTP_CONN_INVALID;
			conntrack_unlock(s->ce);
			return PROTO_INVALID;
	}

	conntrack_delayed_cleanup(s->ce, PROTO_TFTP_PKT_TIMER, p->ts);
	conntrack_unlock(s->ce);
	return PROTO_OK;
}