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Diffstat (limited to 'drivers/net/wireless/intel/iwlwifi/mei/net.c')
-rw-r--r--drivers/net/wireless/intel/iwlwifi/mei/net.c412
1 files changed, 412 insertions, 0 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/net.c b/drivers/net/wireless/intel/iwlwifi/mei/net.c
new file mode 100644
index 000000000..eac46d1a3
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mei/net.c
@@ -0,0 +1,412 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021-2022 Intel Corporation
+ */
+
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_arp.h>
+#include <uapi/linux/icmp.h>
+
+#include <linux/etherdevice.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/ieee80211.h>
+
+#include <net/cfg80211.h>
+#include <net/ip.h>
+
+#include <linux/if_arp.h>
+#include <linux/icmp.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <linux/mm.h>
+
+#include "internal.h"
+#include "sap.h"
+#include "iwl-mei.h"
+
+/*
+ * Returns true if further filtering should be stopped. Only in that case
+ * pass_to_csme and rx_handler_res are set. Otherwise, next level of filters
+ * should be checked.
+ */
+static bool iwl_mei_rx_filter_eth(const struct ethhdr *ethhdr,
+ const struct iwl_sap_oob_filters *filters,
+ bool *pass_to_csme,
+ rx_handler_result_t *rx_handler_res)
+{
+ const struct iwl_sap_eth_filter *filt;
+
+ /* This filter is not relevant for UCAST packet */
+ if (!is_multicast_ether_addr(ethhdr->h_dest) ||
+ is_broadcast_ether_addr(ethhdr->h_dest))
+ return false;
+
+ for (filt = &filters->eth_filters[0];
+ filt < &filters->eth_filters[0] + ARRAY_SIZE(filters->eth_filters);
+ filt++) {
+ /* Assume there are no enabled filter after a disabled one */
+ if (!(filt->flags & SAP_ETH_FILTER_ENABLED))
+ break;
+
+ if (compare_ether_header(filt->mac_address, ethhdr->h_dest))
+ continue;
+
+ /* Packet needs to reach the host's stack */
+ if (filt->flags & SAP_ETH_FILTER_COPY)
+ *rx_handler_res = RX_HANDLER_PASS;
+ else
+ *rx_handler_res = RX_HANDLER_CONSUMED;
+
+ /* We have an authoritative answer, stop filtering */
+ if (filt->flags & SAP_ETH_FILTER_STOP) {
+ *pass_to_csme = true;
+ return true;
+ }
+
+ return false;
+ }
+
+ /* MCAST frames that don't match layer 2 filters are not sent to ME */
+ *pass_to_csme = false;
+
+ return true;
+}
+
+/*
+ * Returns true iff the frame should be passed to CSME in which case
+ * rx_handler_res is set.
+ */
+static bool iwl_mei_rx_filter_arp(struct sk_buff *skb,
+ const struct iwl_sap_oob_filters *filters,
+ rx_handler_result_t *rx_handler_res)
+{
+ const struct iwl_sap_ipv4_filter *filt = &filters->ipv4_filter;
+ const struct arphdr *arp;
+ const __be32 *target_ip;
+ u32 flags = le32_to_cpu(filt->flags);
+
+ if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
+ return false;
+
+ arp = arp_hdr(skb);
+
+ /* Handle only IPv4 over ethernet ARP frames */
+ if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
+ arp->ar_pro != htons(ETH_P_IP))
+ return false;
+
+ /*
+ * After the ARP header, we have:
+ * src MAC address - 6 bytes
+ * src IP address - 4 bytes
+ * target MAC addess - 6 bytes
+ */
+ target_ip = (const void *)((const u8 *)(arp + 1) +
+ ETH_ALEN + sizeof(__be32) + ETH_ALEN);
+
+ /*
+ * ARP request is forwarded to ME only if IP address match in the
+ * ARP request's target ip field.
+ */
+ if (arp->ar_op == htons(ARPOP_REQUEST) &&
+ (filt->flags & cpu_to_le32(SAP_IPV4_FILTER_ARP_REQ_PASS)) &&
+ (filt->ipv4_addr == 0 || filt->ipv4_addr == *target_ip)) {
+ if (flags & SAP_IPV4_FILTER_ARP_REQ_COPY)
+ *rx_handler_res = RX_HANDLER_PASS;
+ else
+ *rx_handler_res = RX_HANDLER_CONSUMED;
+
+ return true;
+ }
+
+ /* ARP reply is always forwarded to ME regardless of the IP */
+ if (flags & SAP_IPV4_FILTER_ARP_RESP_PASS &&
+ arp->ar_op == htons(ARPOP_REPLY)) {
+ if (flags & SAP_IPV4_FILTER_ARP_RESP_COPY)
+ *rx_handler_res = RX_HANDLER_PASS;
+ else
+ *rx_handler_res = RX_HANDLER_CONSUMED;
+
+ return true;
+ }
+
+ return false;
+}
+
+static bool
+iwl_mei_rx_filter_tcp_udp(struct sk_buff *skb, bool ip_match,
+ const struct iwl_sap_oob_filters *filters,
+ rx_handler_result_t *rx_handler_res)
+{
+ const struct iwl_sap_flex_filter *filt;
+
+ for (filt = &filters->flex_filters[0];
+ filt < &filters->flex_filters[0] + ARRAY_SIZE(filters->flex_filters);
+ filt++) {
+ if (!(filt->flags & SAP_FLEX_FILTER_ENABLED))
+ break;
+
+ /*
+ * We are required to have a match on the IP level and we didn't
+ * have such match.
+ */
+ if ((filt->flags &
+ (SAP_FLEX_FILTER_IPV4 | SAP_FLEX_FILTER_IPV6)) &&
+ !ip_match)
+ continue;
+
+ if ((filt->flags & SAP_FLEX_FILTER_UDP) &&
+ ip_hdr(skb)->protocol != IPPROTO_UDP)
+ continue;
+
+ if ((filt->flags & SAP_FLEX_FILTER_TCP) &&
+ ip_hdr(skb)->protocol != IPPROTO_TCP)
+ continue;
+
+ /*
+ * We must have either a TCP header or a UDP header, both
+ * starts with a source port and then a destination port.
+ * Both are big endian words.
+ * Use a UDP header and that will work for TCP as well.
+ */
+ if ((filt->src_port && filt->src_port != udp_hdr(skb)->source) ||
+ (filt->dst_port && filt->dst_port != udp_hdr(skb)->dest))
+ continue;
+
+ if (filt->flags & SAP_FLEX_FILTER_COPY)
+ *rx_handler_res = RX_HANDLER_PASS;
+ else
+ *rx_handler_res = RX_HANDLER_CONSUMED;
+
+ return true;
+ }
+
+ return false;
+}
+
+static bool iwl_mei_rx_filter_ipv4(struct sk_buff *skb,
+ const struct iwl_sap_oob_filters *filters,
+ rx_handler_result_t *rx_handler_res)
+{
+ const struct iwl_sap_ipv4_filter *filt = &filters->ipv4_filter;
+ const struct iphdr *iphdr;
+ unsigned int iphdrlen;
+ bool match;
+
+ if (!pskb_may_pull(skb, skb_network_offset(skb) + sizeof(*iphdr)) ||
+ !pskb_may_pull(skb, skb_network_offset(skb) + ip_hdrlen(skb)))
+ return false;
+
+ iphdrlen = ip_hdrlen(skb);
+ iphdr = ip_hdr(skb);
+ match = !filters->ipv4_filter.ipv4_addr ||
+ filters->ipv4_filter.ipv4_addr == iphdr->daddr;
+
+ skb_set_transport_header(skb, skb_network_offset(skb) + iphdrlen);
+
+ switch (ip_hdr(skb)->protocol) {
+ case IPPROTO_UDP:
+ case IPPROTO_TCP:
+ /*
+ * UDP header is shorter than TCP header and we look at the first bytes
+ * of the header anyway (see below).
+ * If we have a truncated TCP packet, let CSME handle this.
+ */
+ if (!pskb_may_pull(skb, skb_transport_offset(skb) +
+ sizeof(struct udphdr)))
+ return false;
+
+ return iwl_mei_rx_filter_tcp_udp(skb, match,
+ filters, rx_handler_res);
+
+ case IPPROTO_ICMP: {
+ struct icmphdr *icmp;
+
+ if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(*icmp)))
+ return false;
+
+ icmp = icmp_hdr(skb);
+
+ /*
+ * Don't pass echo requests to ME even if it wants it as we
+ * want the host to answer.
+ */
+ if ((filt->flags & cpu_to_le32(SAP_IPV4_FILTER_ICMP_PASS)) &&
+ match && (icmp->type != ICMP_ECHO || icmp->code != 0)) {
+ if (filt->flags & cpu_to_le32(SAP_IPV4_FILTER_ICMP_COPY))
+ *rx_handler_res = RX_HANDLER_PASS;
+ else
+ *rx_handler_res = RX_HANDLER_CONSUMED;
+
+ return true;
+ }
+ break;
+ }
+ case IPPROTO_ICMPV6:
+ /* TODO: Should we have the same ICMP request logic here too? */
+ if ((filters->icmpv6_flags & cpu_to_le32(SAP_ICMPV6_FILTER_ENABLED) &&
+ match)) {
+ if (filters->icmpv6_flags &
+ cpu_to_le32(SAP_ICMPV6_FILTER_COPY))
+ *rx_handler_res = RX_HANDLER_PASS;
+ else
+ *rx_handler_res = RX_HANDLER_CONSUMED;
+
+ return true;
+ }
+ break;
+ default:
+ return false;
+ }
+
+ return false;
+}
+
+static bool iwl_mei_rx_filter_ipv6(struct sk_buff *skb,
+ const struct iwl_sap_oob_filters *filters,
+ rx_handler_result_t *rx_handler_res)
+{
+ *rx_handler_res = RX_HANDLER_PASS;
+
+ /* TODO */
+
+ return false;
+}
+
+static rx_handler_result_t
+iwl_mei_rx_pass_to_csme(struct sk_buff *skb,
+ const struct iwl_sap_oob_filters *filters,
+ bool *pass_to_csme)
+{
+ const struct ethhdr *ethhdr = (void *)skb_mac_header(skb);
+ rx_handler_result_t rx_handler_res = RX_HANDLER_PASS;
+ bool (*filt_handler)(struct sk_buff *skb,
+ const struct iwl_sap_oob_filters *filters,
+ rx_handler_result_t *rx_handler_res);
+
+ /*
+ * skb->data points the IP header / ARP header and the ETH header
+ * is in the headroom.
+ */
+ skb_reset_network_header(skb);
+
+ /*
+ * MCAST IP packets sent by us are received again here without
+ * an ETH header. Drop them here.
+ */
+ if (!skb_mac_offset(skb))
+ return RX_HANDLER_PASS;
+
+ if (skb_headroom(skb) < sizeof(*ethhdr))
+ return RX_HANDLER_PASS;
+
+ if (iwl_mei_rx_filter_eth(ethhdr, filters,
+ pass_to_csme, &rx_handler_res))
+ return rx_handler_res;
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ filt_handler = iwl_mei_rx_filter_ipv4;
+ break;
+ case htons(ETH_P_ARP):
+ filt_handler = iwl_mei_rx_filter_arp;
+ break;
+ case htons(ETH_P_IPV6):
+ filt_handler = iwl_mei_rx_filter_ipv6;
+ break;
+ default:
+ *pass_to_csme = false;
+ return rx_handler_res;
+ }
+
+ *pass_to_csme = filt_handler(skb, filters, &rx_handler_res);
+
+ return rx_handler_res;
+}
+
+rx_handler_result_t iwl_mei_rx_filter(struct sk_buff *orig_skb,
+ const struct iwl_sap_oob_filters *filters,
+ bool *pass_to_csme)
+{
+ rx_handler_result_t ret;
+ struct sk_buff *skb;
+
+ ret = iwl_mei_rx_pass_to_csme(orig_skb, filters, pass_to_csme);
+
+ if (!*pass_to_csme)
+ return RX_HANDLER_PASS;
+
+ if (ret == RX_HANDLER_PASS) {
+ skb = skb_copy(orig_skb, GFP_ATOMIC);
+
+ if (!skb)
+ return RX_HANDLER_PASS;
+ } else {
+ skb = orig_skb;
+ }
+
+ /* CSME wants the MAC header as well, push it back */
+ skb_push(skb, skb->data - skb_mac_header(skb));
+
+ /*
+ * Add the packet that CSME wants to get to the ring. Don't send the
+ * Check Shared Area HECI message since this is not possible from the
+ * Rx context. The caller will schedule a worker to do just that.
+ */
+ iwl_mei_add_data_to_ring(skb, false);
+
+ /*
+ * In case we drop the packet, don't free it, the caller will do that
+ * for us
+ */
+ if (ret == RX_HANDLER_PASS)
+ dev_kfree_skb(skb);
+
+ return ret;
+}
+
+#define DHCP_SERVER_PORT 67
+#define DHCP_CLIENT_PORT 68
+void iwl_mei_tx_copy_to_csme(struct sk_buff *origskb, unsigned int ivlen)
+{
+ struct ieee80211_hdr *hdr;
+ struct sk_buff *skb;
+ struct ethhdr ethhdr;
+ struct ethhdr *eth;
+
+ /* Catch DHCP packets */
+ if (origskb->protocol != htons(ETH_P_IP) ||
+ ip_hdr(origskb)->protocol != IPPROTO_UDP ||
+ udp_hdr(origskb)->source != htons(DHCP_CLIENT_PORT) ||
+ udp_hdr(origskb)->dest != htons(DHCP_SERVER_PORT))
+ return;
+
+ /*
+ * We could be a bit less aggressive here and not copy everything, but
+ * this is very rare anyway, do don't bother much.
+ */
+ skb = skb_copy(origskb, GFP_ATOMIC);
+ if (!skb)
+ return;
+
+ skb->protocol = origskb->protocol;
+
+ hdr = (void *)skb->data;
+
+ memcpy(ethhdr.h_dest, ieee80211_get_DA(hdr), ETH_ALEN);
+ memcpy(ethhdr.h_source, ieee80211_get_SA(hdr), ETH_ALEN);
+
+ /*
+ * Remove the ieee80211 header + IV + SNAP but leave the ethertype
+ * We still have enough headroom for the sap header.
+ */
+ pskb_pull(skb, ieee80211_hdrlen(hdr->frame_control) + ivlen + 6);
+ eth = skb_push(skb, sizeof(ethhdr.h_dest) + sizeof(ethhdr.h_source));
+ memcpy(eth, &ethhdr, sizeof(ethhdr.h_dest) + sizeof(ethhdr.h_source));
+
+ iwl_mei_add_data_to_ring(skb, true);
+
+ dev_kfree_skb(skb);
+}
+EXPORT_SYMBOL_GPL(iwl_mei_tx_copy_to_csme);
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-31 13:38:45 +0000