/* * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. * Copyright (c) 2016 FUJITSU LIMITED * Copyright (c) 2016 Intel Corporation * * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com> * * This work is licensed under the terms of the GNU GPL, version 2 or * later. See the COPYING file in the top-level directory. */ #include "qemu/osdep.h" #include "trace.h" #include "net/colo.h" #include "net/filter.h" #include "net/net.h" #include "qemu-common.h" #include "qapi/error.h" #include "qapi/qmp/qerror.h" #include "qapi-visit.h" #include "qom/object.h" #include "qemu/main-loop.h" #include "qemu/iov.h" #include "net/checksum.h" #define FILTER_COLO_REWRITER(obj) \ OBJECT_CHECK(RewriterState, (obj), TYPE_FILTER_REWRITER) #define TYPE_FILTER_REWRITER "filter-rewriter" typedef struct RewriterState { NetFilterState parent_obj; NetQueue *incoming_queue; /* hashtable to save connection */ GHashTable *connection_track_table; } RewriterState; static void filter_rewriter_flush(NetFilterState *nf) { RewriterState *s = FILTER_COLO_REWRITER(nf); if (!qemu_net_queue_flush(s->incoming_queue)) { /* Unable to empty the queue, purge remaining packets */ qemu_net_queue_purge(s->incoming_queue, nf->netdev); } } /* * Return 1 on success, if return 0 means the pkt * is not TCP packet */ static int is_tcp_packet(Packet *pkt) { if (!parse_packet_early(pkt) && pkt->ip->ip_p == IPPROTO_TCP) { return 1; } else { return 0; } } /* handle tcp packet from primary guest */ static int handle_primary_tcp_pkt(NetFilterState *nf, Connection *conn, Packet *pkt) { struct tcphdr *tcp_pkt; tcp_pkt = (struct tcphdr *)pkt->transport_header; if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) { trace_colo_filter_rewriter_pkt_info(__func__, inet_ntoa(pkt->ip->ip_src), inet_ntoa(pkt->ip->ip_dst), ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack), tcp_pkt->th_flags); trace_colo_filter_rewriter_conn_offset(conn->offset); } if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_SYN)) { /* * we use this flag update offset func * run once in independent tcp connection */ conn->syn_flag = 1; } if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK)) { if (conn->syn_flag) { /* * offset = secondary_seq - primary seq * ack packet sent by guest from primary node, * so we use th_ack - 1 get primary_seq */ conn->offset -= (ntohl(tcp_pkt->th_ack) - 1); conn->syn_flag = 0; } if (conn->offset) { /* handle packets to the secondary from the primary */ tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset); net_checksum_calculate((uint8_t *)pkt->data, pkt->size); } } return 0; } /* handle tcp packet from secondary guest */ static int handle_secondary_tcp_pkt(NetFilterState *nf, Connection *conn, Packet *pkt) { struct tcphdr *tcp_pkt; tcp_pkt = (struct tcphdr *)pkt->transport_header; if (trace_event_get_state(TRACE_COLO_FILTER_REWRITER_DEBUG)) { trace_colo_filter_rewriter_pkt_info(__func__, inet_ntoa(pkt->ip->ip_src), inet_ntoa(pkt->ip->ip_dst), ntohl(tcp_pkt->th_seq), ntohl(tcp_pkt->th_ack), tcp_pkt->th_flags); trace_colo_filter_rewriter_conn_offset(conn->offset); } if (((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == (TH_ACK | TH_SYN))) { /* * save offset = secondary_seq and then * in handle_primary_tcp_pkt make offset * = secondary_seq - primary_seq */ conn->offset = ntohl(tcp_pkt->th_seq); } if ((tcp_pkt->th_flags & (TH_ACK | TH_SYN)) == TH_ACK) { /* Only need to adjust seq while offset is Non-zero */ if (conn->offset) { /* handle packets to the primary from the secondary*/ tcp_pkt->th_seq = htonl(ntohl(tcp_pkt->th_seq) - conn->offset); net_checksum_calculate((uint8_t *)pkt->data, pkt->size); } } return 0; } static ssize_t colo_rewriter_receive_iov(NetFilterState *nf, NetClientState *sender, unsigned flags, const struct iovec *iov, int iovcnt, NetPacketSent *sent_cb) { RewriterState *s = FILTER_COLO_REWRITER(nf); Connection *conn; ConnectionKey key; Packet *pkt; ssize_t size = iov_size(iov, iovcnt); char *buf = g_malloc0(size); iov_to_buf(iov, iovcnt, 0, buf, size); pkt = packet_new(buf, size); g_free(buf); /* * if we get tcp packet * we will rewrite it to make secondary guest's * connection established successfully */ if (pkt && is_tcp_packet(pkt)) { fill_connection_key(pkt, &key); if (sender == nf->netdev) { /* * We need make tcp TX and RX packet * into one connection. */ reverse_connection_key(&key); } conn = connection_get(s->connection_track_table, &key, NULL); if (sender == nf->netdev) { /* NET_FILTER_DIRECTION_TX */ if (!handle_primary_tcp_pkt(nf, conn, pkt)) { qemu_net_queue_send(s->incoming_queue, sender, 0, (const uint8_t *)pkt->data, pkt->size, NULL); packet_destroy(pkt, NULL); pkt = NULL; /* * We block the packet here,after rewrite pkt * and will send it */ return 1; } } else { /* NET_FILTER_DIRECTION_RX */ if (!handle_secondary_tcp_pkt(nf, conn, pkt)) { qemu_net_queue_send(s->incoming_queue, sender, 0, (const uint8_t *)pkt->data, pkt->size, NULL); packet_destroy(pkt, NULL); pkt = NULL; /* * We block the packet here,after rewrite pkt * and will send it */ return 1; } } } packet_destroy(pkt, NULL); pkt = NULL; return 0; } static void colo_rewriter_cleanup(NetFilterState *nf) { RewriterState *s = FILTER_COLO_REWRITER(nf); /* flush packets */ if (s->incoming_queue) { filter_rewriter_flush(nf); g_free(s->incoming_queue); } } static void colo_rewriter_setup(NetFilterState *nf, Error **errp) { RewriterState *s = FILTER_COLO_REWRITER(nf); s->connection_track_table = g_hash_table_new_full(connection_key_hash, connection_key_equal, g_free, connection_destroy); s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf); } static void colo_rewriter_class_init(ObjectClass *oc, void *data) { NetFilterClass *nfc = NETFILTER_CLASS(oc); nfc->setup = colo_rewriter_setup; nfc->cleanup = colo_rewriter_cleanup; nfc->receive_iov = colo_rewriter_receive_iov; } static const TypeInfo colo_rewriter_info = { .name = TYPE_FILTER_REWRITER, .parent = TYPE_NETFILTER, .class_init = colo_rewriter_class_init, .instance_size = sizeof(RewriterState), }; static void register_types(void) { type_register_static(&colo_rewriter_info); } type_init(register_types);