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14#include <linux/netdevice.h>
15#include <net/net_namespace.h>
16#include <net/llc.h>
17#include <net/llc_pdu.h>
18#include <net/llc_sap.h>
19
20#if 0
21#define dprintk(args...) printk(KERN_DEBUG args)
22#else
23#define dprintk(args...)
24#endif
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31
32static void (*llc_station_handler)(struct sk_buff *skb);
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36
37static void (*llc_type_handlers[2])(struct llc_sap *sap,
38 struct sk_buff *skb);
39
40void llc_add_pack(int type, void (*handler)(struct llc_sap *sap,
41 struct sk_buff *skb))
42{
43 if (type == LLC_DEST_SAP || type == LLC_DEST_CONN)
44 llc_type_handlers[type - 1] = handler;
45}
46
47void llc_remove_pack(int type)
48{
49 if (type == LLC_DEST_SAP || type == LLC_DEST_CONN)
50 llc_type_handlers[type - 1] = NULL;
51}
52
53void llc_set_station_handler(void (*handler)(struct sk_buff *skb))
54{
55 llc_station_handler = handler;
56}
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63
64static __inline__ int llc_pdu_type(struct sk_buff *skb)
65{
66 int type = LLC_DEST_CONN;
67 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
68
69 if ((pdu->ctrl_1 & LLC_PDU_TYPE_MASK) != LLC_PDU_TYPE_U)
70 goto out;
71 switch (LLC_U_PDU_CMD(pdu)) {
72 case LLC_1_PDU_CMD_XID:
73 case LLC_1_PDU_CMD_UI:
74 case LLC_1_PDU_CMD_TEST:
75 type = LLC_DEST_SAP;
76 break;
77 case LLC_2_PDU_CMD_SABME:
78 case LLC_2_PDU_CMD_DISC:
79 case LLC_2_PDU_RSP_UA:
80 case LLC_2_PDU_RSP_DM:
81 case LLC_2_PDU_RSP_FRMR:
82 break;
83 default:
84 type = LLC_DEST_INVALID;
85 break;
86 }
87out:
88 return type;
89}
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99
100static inline int llc_fixup_skb(struct sk_buff *skb)
101{
102 u8 llc_len = 2;
103 struct llc_pdu_un *pdu;
104
105 if (unlikely(!pskb_may_pull(skb, sizeof(*pdu))))
106 return 0;
107
108 pdu = (struct llc_pdu_un *)skb->data;
109 if ((pdu->ctrl_1 & LLC_PDU_TYPE_MASK) == LLC_PDU_TYPE_U)
110 llc_len = 1;
111 llc_len += 2;
112
113 if (unlikely(!pskb_may_pull(skb, llc_len)))
114 return 0;
115
116 skb->transport_header += llc_len;
117 skb_pull(skb, llc_len);
118 if (skb->protocol == htons(ETH_P_802_2)) {
119 __be16 pdulen = eth_hdr(skb)->h_proto;
120 u16 data_size = ntohs(pdulen) - llc_len;
121
122 if (unlikely(pskb_trim_rcsum(skb, data_size)))
123 return 0;
124 }
125 return 1;
126}
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139
140int llc_rcv(struct sk_buff *skb, struct net_device *dev,
141 struct packet_type *pt, struct net_device *orig_dev)
142{
143 struct llc_sap *sap;
144 struct llc_pdu_sn *pdu;
145 int dest;
146 int (*rcv)(struct sk_buff *, struct net_device *,
147 struct packet_type *, struct net_device *);
148
149 if (dev->nd_net != &init_net)
150 goto drop;
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155
156 if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
157 dprintk("%s: PACKET_OTHERHOST\n", __FUNCTION__);
158 goto drop;
159 }
160 skb = skb_share_check(skb, GFP_ATOMIC);
161 if (unlikely(!skb))
162 goto out;
163 if (unlikely(!llc_fixup_skb(skb)))
164 goto drop;
165 pdu = llc_pdu_sn_hdr(skb);
166 if (unlikely(!pdu->dsap))
167 goto handle_station;
168 sap = llc_sap_find(pdu->dsap);
169 if (unlikely(!sap)) {
170 dprintk("%s: llc_sap_find(%02X) failed!\n", __FUNCTION__,
171 pdu->dsap);
172 goto drop;
173 }
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177
178 rcv = rcu_dereference(sap->rcv_func);
179 if (rcv) {
180 struct sk_buff *cskb = skb_clone(skb, GFP_ATOMIC);
181 if (cskb)
182 rcv(cskb, dev, pt, orig_dev);
183 }
184 dest = llc_pdu_type(skb);
185 if (unlikely(!dest || !llc_type_handlers[dest - 1]))
186 goto drop_put;
187 llc_type_handlers[dest - 1](sap, skb);
188out_put:
189 llc_sap_put(sap);
190out:
191 return 0;
192drop:
193 kfree_skb(skb);
194 goto out;
195drop_put:
196 kfree_skb(skb);
197 goto out_put;
198handle_station:
199 if (!llc_station_handler)
200 goto drop;
201 llc_station_handler(skb);
202 goto out;
203}
204
205EXPORT_SYMBOL(llc_add_pack);
206EXPORT_SYMBOL(llc_remove_pack);
207EXPORT_SYMBOL(llc_set_station_handler);
208