xref: /linux/drivers/net/wireless/intel/iwlwifi/iwl-utils.c (revision 0ad9617c78acbc71373fb341a6f75d4012b01d69)
1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
2 /*
3  * Copyright (C) 2024 Intel Corporation
4  */
5 #include <net/gso.h>
6 #include <linux/ieee80211.h>
7 #include <net/gso.h>
8 #include <net/ip.h>
9 
10 #include "iwl-drv.h"
11 #include "iwl-utils.h"
12 
13 #ifdef CONFIG_INET
14 int iwl_tx_tso_segment(struct sk_buff *skb, unsigned int num_subframes,
15 		       netdev_features_t netdev_flags,
16 		       struct sk_buff_head *mpdus_skbs)
17 {
18 	struct sk_buff *tmp, *next;
19 	struct ieee80211_hdr *hdr = (void *)skb->data;
20 	char cb[sizeof(skb->cb)];
21 	u16 i = 0;
22 	unsigned int tcp_payload_len;
23 	unsigned int mss = skb_shinfo(skb)->gso_size;
24 	bool ipv4 = (skb->protocol == htons(ETH_P_IP));
25 	bool qos = ieee80211_is_data_qos(hdr->frame_control);
26 	u16 ip_base_id = ipv4 ? ntohs(ip_hdr(skb)->id) : 0;
27 
28 	skb_shinfo(skb)->gso_size = num_subframes * mss;
29 	memcpy(cb, skb->cb, sizeof(cb));
30 
31 	next = skb_gso_segment(skb, netdev_flags);
32 	skb_shinfo(skb)->gso_size = mss;
33 	skb_shinfo(skb)->gso_type = ipv4 ? SKB_GSO_TCPV4 : SKB_GSO_TCPV6;
34 
35 	if (IS_ERR(next) && PTR_ERR(next) == -ENOMEM)
36 		return -ENOMEM;
37 
38 	if (WARN_ONCE(IS_ERR(next),
39 		      "skb_gso_segment error: %d\n", (int)PTR_ERR(next)))
40 		return PTR_ERR(next);
41 
42 	if (next)
43 		consume_skb(skb);
44 
45 	skb_list_walk_safe(next, tmp, next) {
46 		memcpy(tmp->cb, cb, sizeof(tmp->cb));
47 		/*
48 		 * Compute the length of all the data added for the A-MSDU.
49 		 * This will be used to compute the length to write in the TX
50 		 * command. We have: SNAP + IP + TCP for n -1 subframes and
51 		 * ETH header for n subframes.
52 		 */
53 		tcp_payload_len = skb_tail_pointer(tmp) -
54 			skb_transport_header(tmp) -
55 			tcp_hdrlen(tmp) + tmp->data_len;
56 
57 		if (ipv4)
58 			ip_hdr(tmp)->id = htons(ip_base_id + i * num_subframes);
59 
60 		if (tcp_payload_len > mss) {
61 			skb_shinfo(tmp)->gso_size = mss;
62 			skb_shinfo(tmp)->gso_type = ipv4 ? SKB_GSO_TCPV4 :
63 							   SKB_GSO_TCPV6;
64 		} else {
65 			if (qos) {
66 				u8 *qc;
67 
68 				if (ipv4)
69 					ip_send_check(ip_hdr(tmp));
70 
71 				qc = ieee80211_get_qos_ctl((void *)tmp->data);
72 				*qc &= ~IEEE80211_QOS_CTL_A_MSDU_PRESENT;
73 			}
74 			skb_shinfo(tmp)->gso_size = 0;
75 		}
76 
77 		skb_mark_not_on_list(tmp);
78 		__skb_queue_tail(mpdus_skbs, tmp);
79 		i++;
80 	}
81 
82 	return 0;
83 }
84 IWL_EXPORT_SYMBOL(iwl_tx_tso_segment);
85 #endif /* CONFIG_INET */
86