1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/export.h> 3 #include <linux/if_vlan.h> 4 #include <net/ip.h> 5 #include <net/tso.h> 6 #include <asm/unaligned.h> 7 8 void tso_build_hdr(const struct sk_buff *skb, char *hdr, struct tso_t *tso, 9 int size, bool is_last) 10 { 11 int hdr_len = skb_transport_offset(skb) + tso->tlen; 12 int mac_hdr_len = skb_network_offset(skb); 13 14 memcpy(hdr, skb->data, hdr_len); 15 if (!tso->ipv6) { 16 struct iphdr *iph = (void *)(hdr + mac_hdr_len); 17 18 iph->id = htons(tso->ip_id); 19 iph->tot_len = htons(size + hdr_len - mac_hdr_len); 20 tso->ip_id++; 21 } else { 22 struct ipv6hdr *iph = (void *)(hdr + mac_hdr_len); 23 24 iph->payload_len = htons(size + tso->tlen); 25 } 26 hdr += skb_transport_offset(skb); 27 if (tso->tlen != sizeof(struct udphdr)) { 28 struct tcphdr *tcph = (struct tcphdr *)hdr; 29 30 put_unaligned_be32(tso->tcp_seq, &tcph->seq); 31 32 if (!is_last) { 33 /* Clear all special flags for not last packet */ 34 tcph->psh = 0; 35 tcph->fin = 0; 36 tcph->rst = 0; 37 } 38 } else { 39 struct udphdr *uh = (struct udphdr *)hdr; 40 41 uh->len = htons(sizeof(*uh) + size); 42 } 43 } 44 EXPORT_SYMBOL(tso_build_hdr); 45 46 void tso_build_data(const struct sk_buff *skb, struct tso_t *tso, int size) 47 { 48 tso->tcp_seq += size; /* not worth avoiding this operation for UDP */ 49 tso->size -= size; 50 tso->data += size; 51 52 if ((tso->size == 0) && 53 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 54 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 55 56 /* Move to next segment */ 57 tso->size = skb_frag_size(frag); 58 tso->data = skb_frag_address(frag); 59 tso->next_frag_idx++; 60 } 61 } 62 EXPORT_SYMBOL(tso_build_data); 63 64 int tso_start(struct sk_buff *skb, struct tso_t *tso) 65 { 66 int tlen = skb_is_gso_tcp(skb) ? tcp_hdrlen(skb) : sizeof(struct udphdr); 67 int hdr_len = skb_transport_offset(skb) + tlen; 68 69 tso->tlen = tlen; 70 tso->ip_id = ntohs(ip_hdr(skb)->id); 71 tso->tcp_seq = (tlen != sizeof(struct udphdr)) ? ntohl(tcp_hdr(skb)->seq) : 0; 72 tso->next_frag_idx = 0; 73 tso->ipv6 = vlan_get_protocol(skb) == htons(ETH_P_IPV6); 74 75 /* Build first data */ 76 tso->size = skb_headlen(skb) - hdr_len; 77 tso->data = skb->data + hdr_len; 78 if ((tso->size == 0) && 79 (tso->next_frag_idx < skb_shinfo(skb)->nr_frags)) { 80 skb_frag_t *frag = &skb_shinfo(skb)->frags[tso->next_frag_idx]; 81 82 /* Move to next segment */ 83 tso->size = skb_frag_size(frag); 84 tso->data = skb_frag_address(frag); 85 tso->next_frag_idx++; 86 } 87 return hdr_len; 88 } 89 EXPORT_SYMBOL(tso_start); 90