struct sk_buff *dccp_make_response(const struct sock *sk, struct dst_entry *dst, struct request_sock *req) { struct dccp_hdr *dh; struct dccp_request_sock *dreq; const u32 dccp_header_size = sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext) + sizeof(struct dccp_hdr_response); struct sk_buff *skb; /* sk is marked const to clearly express we dont hold socket lock. * sock_wmalloc() will atomically change sk->sk_wmem_alloc, * it is safe to promote sk to non const. */ skb = sock_wmalloc((struct sock *)sk, MAX_DCCP_HEADER, 1, GFP_ATOMIC); if (!skb) return NULL; skb_reserve(skb, MAX_DCCP_HEADER); skb_dst_set(skb, dst_clone(dst)); dreq = dccp_rsk(req); if (inet_rsk(req)->acked) /* increase GSS upon retransmission */ dccp_inc_seqno(&dreq->dreq_gss); DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_gss; /* Resolve feature dependencies resulting from choice of CCID */ if (dccp_feat_server_ccid_dependencies(dreq)) goto response_failed; if (dccp_insert_options_rsk(dreq, skb)) goto response_failed; /* Build and checksum header */ dh = dccp_zeroed_hdr(skb, dccp_header_size); dh->dccph_sport = htons(inet_rsk(req)->ir_num); dh->dccph_dport = inet_rsk(req)->ir_rmt_port; dh->dccph_doff = (dccp_header_size + DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; dh->dccph_type = DCCP_PKT_RESPONSE; dh->dccph_x = 1; dccp_hdr_set_seq(dh, dreq->dreq_gss); dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_gsr); dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; dccp_csum_outgoing(skb); /* We use `acked' to remember that a Response was already sent. */ inet_rsk(req)->acked = 1; DCCP_INC_STATS(DCCP_MIB_OUTSEGS); return skb; response_failed: kfree_skb(skb); return NULL; }
struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, struct request_sock *req) { struct dccp_hdr *dh; struct dccp_request_sock *dreq; const u32 dccp_header_size = sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext) + sizeof(struct dccp_hdr_response); struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC); if (skb == NULL) return NULL; /* Reserve space for headers. */ skb_reserve(skb, sk->sk_prot->max_header); skb_dst_set(skb, dst_clone(dst)); dreq = dccp_rsk(req); if (inet_rsk(req)->acked) /* increase ISS upon retransmission */ dccp_inc_seqno(&dreq->dreq_iss); DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; /* Resolve feature dependencies resulting from choice of CCID */ if (dccp_feat_server_ccid_dependencies(dreq)) goto response_failed; if (dccp_insert_options_rsk(dreq, skb)) goto response_failed; /* Build and checksum header */ dh = dccp_zeroed_hdr(skb, dccp_header_size); dh->dccph_sport = inet_rsk(req)->loc_port; dh->dccph_dport = inet_rsk(req)->rmt_port; dh->dccph_doff = (dccp_header_size + DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; dh->dccph_type = DCCP_PKT_RESPONSE; dh->dccph_x = 1; dccp_hdr_set_seq(dh, dreq->dreq_iss); dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; dccp_csum_outgoing(skb); /* We use `acked' to remember that a Response was already sent. */ inet_rsk(req)->acked = 1; DCCP_INC_STATS(DCCP_MIB_OUTSEGS); return skb; response_failed: kfree_skb(skb); return NULL; }
struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, struct request_sock *req) { struct dccp_hdr *dh; struct dccp_request_sock *dreq; const u32 dccp_header_size = sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext) + sizeof(struct dccp_hdr_response); struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC); if (skb == NULL) return NULL; skb_reserve(skb, sk->sk_prot->max_header); skb_dst_set(skb, dst_clone(dst)); dreq = dccp_rsk(req); if (inet_rsk(req)->acked) dccp_inc_seqno(&dreq->dreq_iss); DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; if (dccp_feat_server_ccid_dependencies(dreq)) goto response_failed; if (dccp_insert_options_rsk(dreq, skb)) goto response_failed; dh = dccp_zeroed_hdr(skb, dccp_header_size); dh->dccph_sport = inet_rsk(req)->loc_port; dh->dccph_dport = inet_rsk(req)->rmt_port; dh->dccph_doff = (dccp_header_size + DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; dh->dccph_type = DCCP_PKT_RESPONSE; dh->dccph_x = 1; dccp_hdr_set_seq(dh, dreq->dreq_iss); dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; dccp_csum_outgoing(skb); inet_rsk(req)->acked = 1; DCCP_INC_STATS(DCCP_MIB_OUTSEGS); return skb; response_failed: kfree_skb(skb); return NULL; }
struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, struct request_sock *req) { struct dccp_hdr *dh; struct dccp_request_sock *dreq; const int dccp_header_size = sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext) + sizeof(struct dccp_hdr_response); struct sk_buff *skb = sock_wmalloc(sk, MAX_HEADER + DCCP_MAX_OPT_LEN + dccp_header_size, 1, GFP_ATOMIC); if (skb == NULL) return NULL; /* Reserve space for headers. */ skb_reserve(skb, MAX_HEADER + DCCP_MAX_OPT_LEN + dccp_header_size); skb->dst = dst_clone(dst); skb->csum = 0; dreq = dccp_rsk(req); DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; dccp_insert_options(sk, skb); skb->h.raw = skb_push(skb, dccp_header_size); dh = dccp_hdr(skb); memset(dh, 0, dccp_header_size); dh->dccph_sport = inet_sk(sk)->sport; dh->dccph_dport = inet_rsk(req)->rmt_port; dh->dccph_doff = (dccp_header_size + DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; dh->dccph_type = DCCP_PKT_RESPONSE; dh->dccph_x = 1; dccp_hdr_set_seq(dh, dreq->dreq_iss); dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; dh->dccph_checksum = dccp_v4_checksum(skb, inet_rsk(req)->loc_addr, inet_rsk(req)->rmt_addr); DCCP_INC_STATS(DCCP_MIB_OUTSEGS); return skb; }