1// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
  2/*
  3 * Copyright (c) 2020 Mellanox Technologies. All rights reserved.
  4 */
  5
  6#include <rdma/ib_verbs.h>
  7#include <rdma/ib_cache.h>
  8#include <rdma/lag.h>
  9
 10static struct sk_buff *rdma_build_skb(struct net_device *netdev,
 11				      struct rdma_ah_attr *ah_attr,
 12				      gfp_t flags)
 13{
 14	struct ipv6hdr *ip6h;
 15	struct sk_buff *skb;
 16	struct ethhdr *eth;
 17	struct iphdr *iph;
 18	struct udphdr *uh;
 19	u8 smac[ETH_ALEN];
 20	bool is_ipv4;
 21	int hdr_len;
 22
 23	is_ipv4 = ipv6_addr_v4mapped((struct in6_addr *)ah_attr->grh.dgid.raw);
 24	hdr_len = ETH_HLEN + sizeof(struct udphdr) + LL_RESERVED_SPACE(netdev);
 25	hdr_len += is_ipv4 ? sizeof(struct iphdr) : sizeof(struct ipv6hdr);
 26
 27	skb = alloc_skb(hdr_len, flags);
 28	if (!skb)
 29		return NULL;
 30
 31	skb->dev = netdev;
 32	skb_reserve(skb, hdr_len);
 33	skb_push(skb, sizeof(struct udphdr));
 34	skb_reset_transport_header(skb);
 35	uh = udp_hdr(skb);
 36	uh->source =
 37		htons(rdma_flow_label_to_udp_sport(ah_attr->grh.flow_label));
 38	uh->dest = htons(ROCE_V2_UDP_DPORT);
 39	uh->len = htons(sizeof(struct udphdr));
 40
 41	if (is_ipv4) {
 42		skb_push(skb, sizeof(struct iphdr));
 43		skb_reset_network_header(skb);
 44		iph = ip_hdr(skb);
 45		iph->frag_off = 0;
 46		iph->version = 4;
 47		iph->protocol = IPPROTO_UDP;
 48		iph->ihl = 0x5;
 49		iph->tot_len = htons(sizeof(struct udphdr) + sizeof(struct
 50								    iphdr));
 51		memcpy(&iph->saddr, ah_attr->grh.sgid_attr->gid.raw + 12,
 52		       sizeof(struct in_addr));
 53		memcpy(&iph->daddr, ah_attr->grh.dgid.raw + 12,
 54		       sizeof(struct in_addr));
 55	} else {
 56		skb_push(skb, sizeof(struct ipv6hdr));
 57		skb_reset_network_header(skb);
 58		ip6h = ipv6_hdr(skb);
 59		ip6h->version = 6;
 60		ip6h->nexthdr = IPPROTO_UDP;
 61		memcpy(&ip6h->flow_lbl, &ah_attr->grh.flow_label,
 62		       sizeof(*ip6h->flow_lbl));
 63		memcpy(&ip6h->saddr, ah_attr->grh.sgid_attr->gid.raw,
 64		       sizeof(struct in6_addr));
 65		memcpy(&ip6h->daddr, ah_attr->grh.dgid.raw,
 66		       sizeof(struct in6_addr));
 67	}
 68
 69	skb_push(skb, sizeof(struct ethhdr));
 70	skb_reset_mac_header(skb);
 71	eth = eth_hdr(skb);
 72	skb->protocol = eth->h_proto = htons(is_ipv4 ? ETH_P_IP : ETH_P_IPV6);
 73	rdma_read_gid_l2_fields(ah_attr->grh.sgid_attr, NULL, smac);
 74	memcpy(eth->h_source, smac, ETH_ALEN);
 75	memcpy(eth->h_dest, ah_attr->roce.dmac, ETH_ALEN);
 76
 77	return skb;
 78}
 79
 80static struct net_device *rdma_get_xmit_slave_udp(struct ib_device *device,
 81						  struct net_device *master,
 82						  struct rdma_ah_attr *ah_attr,
 83						  gfp_t flags)
 84{
 85	struct net_device *slave;
 86	struct sk_buff *skb;
 87
 88	skb = rdma_build_skb(master, ah_attr, flags);
 89	if (!skb)
 90		return ERR_PTR(-ENOMEM);
 91
 92	rcu_read_lock();
 93	slave = netdev_get_xmit_slave(master, skb,
 94				      !!(device->lag_flags &
 95					 RDMA_LAG_FLAGS_HASH_ALL_SLAVES));
 96	if (slave)
 97		dev_hold(slave);
 98	rcu_read_unlock();
 99	kfree_skb(skb);
100	return slave;
101}
102
103void rdma_lag_put_ah_roce_slave(struct net_device *xmit_slave)
104{
105	dev_put(xmit_slave);
106}
107
108struct net_device *rdma_lag_get_ah_roce_slave(struct ib_device *device,
109					      struct rdma_ah_attr *ah_attr,
110					      gfp_t flags)
111{
112	struct net_device *slave = NULL;
113	struct net_device *master;
114
115	if (!(ah_attr->type == RDMA_AH_ATTR_TYPE_ROCE &&
116	      ah_attr->grh.sgid_attr->gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP &&
117	      ah_attr->grh.flow_label))
118		return NULL;
119
120	rcu_read_lock();
121	master = rdma_read_gid_attr_ndev_rcu(ah_attr->grh.sgid_attr);
122	if (IS_ERR(master)) {
123		rcu_read_unlock();
124		return master;
125	}
126	dev_hold(master);
127	rcu_read_unlock();
128
129	if (!netif_is_bond_master(master))
130		goto put;
131
132	slave = rdma_get_xmit_slave_udp(device, master, ah_attr, flags);
133put:
134	dev_put(master);
135	return slave;
136}