diff options
Diffstat (limited to 'net/eth.c')
| -rw-r--r-- | net/eth.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/net/eth.c b/net/eth.c new file mode 100644 index 0000000000..1d7494d5e5 --- /dev/null +++ b/net/eth.c @@ -0,0 +1,217 @@ +/* + * QEMU network structures definitions and helper functions + * + * Copyright (c) 2012 Ravello Systems LTD (http://ravellosystems.com) + * + * Developed by Daynix Computing LTD (http://www.daynix.com) + * + * Authors: + * Dmitry Fleytman <dmitry@daynix.com> + * Tamir Shomer <tamirs@daynix.com> + * Yan Vugenfirer <yan@daynix.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 "net/eth.h" +#include "net/checksum.h" +#include "qemu-common.h" +#include "net/tap.h" + +void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag, + bool *is_new) +{ + struct vlan_header *vhdr = PKT_GET_VLAN_HDR(ehdr); + + switch (be16_to_cpu(ehdr->h_proto)) { + case ETH_P_VLAN: + case ETH_P_DVLAN: + /* vlan hdr exists */ + *is_new = false; + break; + + default: + /* No VLAN header, put a new one */ + vhdr->h_proto = ehdr->h_proto; + ehdr->h_proto = cpu_to_be16(ETH_P_VLAN); + *is_new = true; + break; + } + vhdr->h_tci = cpu_to_be16(vlan_tag); +} + +uint8_t +eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto) +{ + uint8_t ecn_state = 0; + + if (l3_proto == ETH_P_IP) { + struct ip_header *iphdr = (struct ip_header *) l3_hdr; + + if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) { + if (IPTOS_ECN(iphdr->ip_tos) == IPTOS_ECN_CE) { + ecn_state = VIRTIO_NET_HDR_GSO_ECN; + } + if (l4proto == IP_PROTO_TCP) { + return VIRTIO_NET_HDR_GSO_TCPV4 | ecn_state; + } else if (l4proto == IP_PROTO_UDP) { + return VIRTIO_NET_HDR_GSO_UDP | ecn_state; + } + } + } else if (l3_proto == ETH_P_IPV6) { + struct ip6_header *ip6hdr = (struct ip6_header *) l3_hdr; + + if (IP6_ECN(ip6hdr->ip6_ecn_acc) == IP6_ECN_CE) { + ecn_state = VIRTIO_NET_HDR_GSO_ECN; + } + + if (l4proto == IP_PROTO_TCP) { + return VIRTIO_NET_HDR_GSO_TCPV6 | ecn_state; + } + } + + /* Unsupported offload */ + assert(false); + + return VIRTIO_NET_HDR_GSO_NONE | ecn_state; +} + +void eth_get_protocols(const uint8_t *headers, + uint32_t hdr_length, + bool *isip4, bool *isip6, + bool *isudp, bool *istcp) +{ + int proto; + size_t l2hdr_len = eth_get_l2_hdr_length(headers); + assert(hdr_length >= eth_get_l2_hdr_length(headers)); + *isip4 = *isip6 = *isudp = *istcp = false; + + proto = eth_get_l3_proto(headers, l2hdr_len); + if (proto == ETH_P_IP) { + *isip4 = true; + + struct ip_header *iphdr; + + assert(hdr_length >= + eth_get_l2_hdr_length(headers) + sizeof(struct ip_header)); + + iphdr = PKT_GET_IP_HDR(headers); + + if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) { + if (iphdr->ip_p == IP_PROTO_TCP) { + *istcp = true; + } else if (iphdr->ip_p == IP_PROTO_UDP) { + *isudp = true; + } + } + } else if (proto == ETH_P_IPV6) { + uint8_t l4proto; + size_t full_ip6hdr_len; + + struct iovec hdr_vec; + hdr_vec.iov_base = (void *) headers; + hdr_vec.iov_len = hdr_length; + + *isip6 = true; + if (eth_parse_ipv6_hdr(&hdr_vec, 1, l2hdr_len, + &l4proto, &full_ip6hdr_len)) { + if (l4proto == IP_PROTO_TCP) { + *istcp = true; + } else if (l4proto == IP_PROTO_UDP) { + *isudp = true; + } + } + } +} + +void +eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len, + void *l3hdr, size_t l3hdr_len, + size_t l3payload_len, + size_t frag_offset, bool more_frags) +{ + if (eth_get_l3_proto(l2hdr, l2hdr_len) == ETH_P_IP) { + uint16_t orig_flags; + struct ip_header *iphdr = (struct ip_header *) l3hdr; + uint16_t frag_off_units = frag_offset / IP_FRAG_UNIT_SIZE; + uint16_t new_ip_off; + + assert(frag_offset % IP_FRAG_UNIT_SIZE == 0); + assert((frag_off_units & ~IP_OFFMASK) == 0); + + orig_flags = be16_to_cpu(iphdr->ip_off) & ~(IP_OFFMASK|IP_MF); + new_ip_off = frag_off_units | orig_flags | (more_frags ? IP_MF : 0); + iphdr->ip_off = cpu_to_be16(new_ip_off); + iphdr->ip_len = cpu_to_be16(l3payload_len + l3hdr_len); + } +} + +void +eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len) +{ + struct ip_header *iphdr = (struct ip_header *) l3hdr; + iphdr->ip_sum = 0; + iphdr->ip_sum = cpu_to_be16(net_raw_checksum(l3hdr, l3hdr_len)); +} + +uint32_t +eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl) +{ + struct ip_pseudo_header ipph; + ipph.ip_src = iphdr->ip_src; + ipph.ip_dst = iphdr->ip_dst; + ipph.ip_payload = cpu_to_be16(csl); + ipph.ip_proto = iphdr->ip_p; + ipph.zeros = 0; + return net_checksum_add(sizeof(ipph), (uint8_t *) &ipph); +} + +static bool +eth_is_ip6_extension_header_type(uint8_t hdr_type) +{ + switch (hdr_type) { + case IP6_HOP_BY_HOP: + case IP6_ROUTING: + case IP6_FRAGMENT: + case IP6_ESP: + case IP6_AUTHENTICATION: + case IP6_DESTINATON: + case IP6_MOBILITY: + return true; + default: + return false; + } +} + +bool eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags, + size_t ip6hdr_off, uint8_t *l4proto, + size_t *full_hdr_len) +{ + struct ip6_header ip6_hdr; + struct ip6_ext_hdr ext_hdr; + size_t bytes_read; + + bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off, + &ip6_hdr, sizeof(ip6_hdr)); + if (bytes_read < sizeof(ip6_hdr)) { + return false; + } + + *full_hdr_len = sizeof(struct ip6_header); + + if (!eth_is_ip6_extension_header_type(ip6_hdr.ip6_nxt)) { + *l4proto = ip6_hdr.ip6_nxt; + return true; + } + + do { + bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off + *full_hdr_len, + &ext_hdr, sizeof(ext_hdr)); + *full_hdr_len += (ext_hdr.ip6r_len + 1) * IP6_EXT_GRANULARITY; + } while (eth_is_ip6_extension_header_type(ext_hdr.ip6r_nxt)); + + *l4proto = ext_hdr.ip6r_nxt; + return true; +} |