[qemu.git] / net / eth.c

/*
 * 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 */
    g_assert_not_reached();

    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;
}
Commit	Line	Data
75020a70 DF	1	/*
	2	* QEMU network structures definitions and helper functions
	3	*
	4	* Copyright (c) 2012 Ravello Systems LTD (http://ravellosystems.com)
	5	*
	6	* Developed by Daynix Computing LTD (http://www.daynix.com)
	7	*
	8	* Authors:
	9	* Dmitry Fleytman <dmitry@daynix.com>
	10	* Tamir Shomer <tamirs@daynix.com>
	11	* Yan Vugenfirer <yan@daynix.com>
	12	*
	13	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	14	* See the COPYING file in the top-level directory.
	15	*
	16	*/
	17
	18	#include "net/eth.h"
	19	#include "net/checksum.h"
	20	#include "qemu-common.h"
	21	#include "net/tap.h"
	22
	23	void eth_setup_vlan_headers(struct eth_header *ehdr, uint16_t vlan_tag,
	24	bool *is_new)
	25	{
	26	struct vlan_header *vhdr = PKT_GET_VLAN_HDR(ehdr);
	27
	28	switch (be16_to_cpu(ehdr->h_proto)) {
	29	case ETH_P_VLAN:
	30	case ETH_P_DVLAN:
	31	/* vlan hdr exists */
	32	*is_new = false;
	33	break;
	34
	35	default:
	36	/* No VLAN header, put a new one */
	37	vhdr->h_proto = ehdr->h_proto;
	38	ehdr->h_proto = cpu_to_be16(ETH_P_VLAN);
	39	*is_new = true;
	40	break;
	41	}
	42	vhdr->h_tci = cpu_to_be16(vlan_tag);
	43	}
	44
	45	uint8_t
	46	eth_get_gso_type(uint16_t l3_proto, uint8_t *l3_hdr, uint8_t l4proto)
	47	{
	48	uint8_t ecn_state = 0;
	49
	50	if (l3_proto == ETH_P_IP) {
	51	struct ip_header iphdr = (struct ip_header ) l3_hdr;
	52
	53	if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
	54	if (IPTOS_ECN(iphdr->ip_tos) == IPTOS_ECN_CE) {
	55	ecn_state = VIRTIO_NET_HDR_GSO_ECN;
	56	}
	57	if (l4proto == IP_PROTO_TCP) {
	58	return VIRTIO_NET_HDR_GSO_TCPV4 \| ecn_state;
	59	} else if (l4proto == IP_PROTO_UDP) {
	60	return VIRTIO_NET_HDR_GSO_UDP \| ecn_state;
	61	}
	62	}
	63	} else if (l3_proto == ETH_P_IPV6) {
	64	struct ip6_header ip6hdr = (struct ip6_header ) l3_hdr;
65
66	if (IP6_ECN(ip6hdr->ip6_ecn_acc) == IP6_ECN_CE) {
67	ecn_state = VIRTIO_NET_HDR_GSO_ECN;
68	}
69
70	if (l4proto == IP_PROTO_TCP) {
71	return VIRTIO_NET_HDR_GSO_TCPV6 \| ecn_state;
72	}
73	}
74
75	/* Unsupported offload */
dfc6f865	76	g_assert_not_reached();
75020a70 DF	77
	78	return VIRTIO_NET_HDR_GSO_NONE \| ecn_state;
	79	}
	80
	81	void eth_get_protocols(const uint8_t *headers,
	82	uint32_t hdr_length,
	83	bool isip4, bool isip6,
	84	bool isudp, bool istcp)
	85	{
	86	int proto;
	87	size_t l2hdr_len = eth_get_l2_hdr_length(headers);
	88	assert(hdr_length >= eth_get_l2_hdr_length(headers));
	89	isip4 = isip6 = isudp = istcp = false;
	90
	91	proto = eth_get_l3_proto(headers, l2hdr_len);
	92	if (proto == ETH_P_IP) {
	93	*isip4 = true;
	94
	95	struct ip_header *iphdr;
	96
	97	assert(hdr_length >=
	98	eth_get_l2_hdr_length(headers) + sizeof(struct ip_header));
	99
	100	iphdr = PKT_GET_IP_HDR(headers);
	101
	102	if (IP_HEADER_VERSION(iphdr) == IP_HEADER_VERSION_4) {
	103	if (iphdr->ip_p == IP_PROTO_TCP) {
	104	*istcp = true;
	105	} else if (iphdr->ip_p == IP_PROTO_UDP) {
	106	*isudp = true;
	107	}
	108	}
	109	} else if (proto == ETH_P_IPV6) {
	110	uint8_t l4proto;
	111	size_t full_ip6hdr_len;
	112
	113	struct iovec hdr_vec;
	114	hdr_vec.iov_base = (void *) headers;
	115	hdr_vec.iov_len = hdr_length;
	116
	117	*isip6 = true;
	118	if (eth_parse_ipv6_hdr(&hdr_vec, 1, l2hdr_len,
	119	&l4proto, &full_ip6hdr_len)) {
	120	if (l4proto == IP_PROTO_TCP) {
	121	*istcp = true;
	122	} else if (l4proto == IP_PROTO_UDP) {
	123	*isudp = true;
	124	}
	125	}
	126	}
	127	}
	128
	129	void
	130	eth_setup_ip4_fragmentation(const void *l2hdr, size_t l2hdr_len,
	131	void *l3hdr, size_t l3hdr_len,
	132	size_t l3payload_len,
	133	size_t frag_offset, bool more_frags)
	134	{
	135	if (eth_get_l3_proto(l2hdr, l2hdr_len) == ETH_P_IP) {
	136	uint16_t orig_flags;
	137	struct ip_header iphdr = (struct ip_header ) l3hdr;
	138	uint16_t frag_off_units = frag_offset / IP_FRAG_UNIT_SIZE;
	139	uint16_t new_ip_off;
	140
141	assert(frag_offset % IP_FRAG_UNIT_SIZE == 0);
142	assert((frag_off_units & ~IP_OFFMASK) == 0);
143
144	orig_flags = be16_to_cpu(iphdr->ip_off) & ~(IP_OFFMASK\|IP_MF);
145	new_ip_off = frag_off_units \| orig_flags \| (more_frags ? IP_MF : 0);
146	iphdr->ip_off = cpu_to_be16(new_ip_off);
147	iphdr->ip_len = cpu_to_be16(l3payload_len + l3hdr_len);
148	}
149	}
150
151	void
152	eth_fix_ip4_checksum(void *l3hdr, size_t l3hdr_len)
153	{
154	struct ip_header iphdr = (struct ip_header ) l3hdr;
155	iphdr->ip_sum = 0;
156	iphdr->ip_sum = cpu_to_be16(net_raw_checksum(l3hdr, l3hdr_len));
157	}
158
159	uint32_t
160	eth_calc_pseudo_hdr_csum(struct ip_header *iphdr, uint16_t csl)
161	{
162	struct ip_pseudo_header ipph;
163	ipph.ip_src = iphdr->ip_src;
164	ipph.ip_dst = iphdr->ip_dst;
165	ipph.ip_payload = cpu_to_be16(csl);
166	ipph.ip_proto = iphdr->ip_p;
167	ipph.zeros = 0;
168	return net_checksum_add(sizeof(ipph), (uint8_t *) &ipph);
169	}
170
171	static bool
172	eth_is_ip6_extension_header_type(uint8_t hdr_type)
173	{
174	switch (hdr_type) {
175	case IP6_HOP_BY_HOP:
176	case IP6_ROUTING:
177	case IP6_FRAGMENT:
178	case IP6_ESP:
179	case IP6_AUTHENTICATION:
180	case IP6_DESTINATON:
181	case IP6_MOBILITY:
182	return true;
183	default:
184	return false;
185	}
186	}
187
188	bool eth_parse_ipv6_hdr(struct iovec *pkt, int pkt_frags,
189	size_t ip6hdr_off, uint8_t *l4proto,
190	size_t *full_hdr_len)
191	{
192	struct ip6_header ip6_hdr;
193	struct ip6_ext_hdr ext_hdr;
194	size_t bytes_read;
195
196	bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off,
197	&ip6_hdr, sizeof(ip6_hdr));
198	if (bytes_read < sizeof(ip6_hdr)) {
199	return false;
200	}
201
202	*full_hdr_len = sizeof(struct ip6_header);
203
204	if (!eth_is_ip6_extension_header_type(ip6_hdr.ip6_nxt)) {
205	*l4proto = ip6_hdr.ip6_nxt;
206	return true;
207	}
208
209	do {
210	bytes_read = iov_to_buf(pkt, pkt_frags, ip6hdr_off + *full_hdr_len,
211	&ext_hdr, sizeof(ext_hdr));
212	full_hdr_len += (ext_hdr.ip6r_len + 1) IP6_EXT_GRANULARITY;
213	} while (eth_is_ip6_extension_header_type(ext_hdr.ip6r_nxt));
214
215	*l4proto = ext_hdr.ip6r_nxt;
216	return true;
217	}