ia64/linux-2.6.18-xen.hg

view net/llc/llc_input.c @ 673:3161879fdf22

[IA64] xencomm: support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap

support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Tue Sep 16 21:26:15 2008 +0900 (2008-09-16)
parents 831230e53067
children
line source
1 /*
2 * llc_input.c - Minimal input path for LLC
3 *
4 * Copyright (c) 1997 by Procom Technology, Inc.
5 * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program can be redistributed or modified under the terms of the
8 * GNU General Public License as published by the Free Software Foundation.
9 * This program is distributed without any warranty or implied warranty
10 * of merchantability or fitness for a particular purpose.
11 *
12 * See the GNU General Public License for more details.
13 */
14 #include <linux/netdevice.h>
15 #include <net/llc.h>
16 #include <net/llc_pdu.h>
17 #include <net/llc_sap.h>
19 #if 0
20 #define dprintk(args...) printk(KERN_DEBUG args)
21 #else
22 #define dprintk(args...)
23 #endif
25 /*
26 * Packet handler for the station, registerable because in the minimal
27 * LLC core that is taking shape only the very minimal subset of LLC that
28 * is needed for things like IPX, Appletalk, etc will stay, with all the
29 * rest in the llc1 and llc2 modules.
30 */
31 static void (*llc_station_handler)(struct sk_buff *skb);
33 /*
34 * Packet handlers for LLC_DEST_SAP and LLC_DEST_CONN.
35 */
36 static void (*llc_type_handlers[2])(struct llc_sap *sap,
37 struct sk_buff *skb);
39 void llc_add_pack(int type, void (*handler)(struct llc_sap *sap,
40 struct sk_buff *skb))
41 {
42 if (type == LLC_DEST_SAP || type == LLC_DEST_CONN)
43 llc_type_handlers[type - 1] = handler;
44 }
46 void llc_remove_pack(int type)
47 {
48 if (type == LLC_DEST_SAP || type == LLC_DEST_CONN)
49 llc_type_handlers[type - 1] = NULL;
50 }
52 void llc_set_station_handler(void (*handler)(struct sk_buff *skb))
53 {
54 llc_station_handler = handler;
55 }
57 /**
58 * llc_pdu_type - returns which LLC component must handle for PDU
59 * @skb: input skb
60 *
61 * This function returns which LLC component must handle this PDU.
62 */
63 static __inline__ int llc_pdu_type(struct sk_buff *skb)
64 {
65 int type = LLC_DEST_CONN; /* I-PDU or S-PDU type */
66 struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
68 if ((pdu->ctrl_1 & LLC_PDU_TYPE_MASK) != LLC_PDU_TYPE_U)
69 goto out;
70 switch (LLC_U_PDU_CMD(pdu)) {
71 case LLC_1_PDU_CMD_XID:
72 case LLC_1_PDU_CMD_UI:
73 case LLC_1_PDU_CMD_TEST:
74 type = LLC_DEST_SAP;
75 break;
76 case LLC_2_PDU_CMD_SABME:
77 case LLC_2_PDU_CMD_DISC:
78 case LLC_2_PDU_RSP_UA:
79 case LLC_2_PDU_RSP_DM:
80 case LLC_2_PDU_RSP_FRMR:
81 break;
82 default:
83 type = LLC_DEST_INVALID;
84 break;
85 }
86 out:
87 return type;
88 }
90 /**
91 * llc_fixup_skb - initializes skb pointers
92 * @skb: This argument points to incoming skb
93 *
94 * Initializes internal skb pointer to start of network layer by deriving
95 * length of LLC header; finds length of LLC control field in LLC header
96 * by looking at the two lowest-order bits of the first control field
97 * byte; field is either 3 or 4 bytes long.
98 */
99 static inline int llc_fixup_skb(struct sk_buff *skb)
100 {
101 u8 llc_len = 2;
102 struct llc_pdu_un *pdu;
104 if (unlikely(!pskb_may_pull(skb, sizeof(*pdu))))
105 return 0;
107 pdu = (struct llc_pdu_un *)skb->data;
108 if ((pdu->ctrl_1 & LLC_PDU_TYPE_MASK) == LLC_PDU_TYPE_U)
109 llc_len = 1;
110 llc_len += 2;
112 if (unlikely(!pskb_may_pull(skb, llc_len)))
113 return 0;
115 skb->h.raw += llc_len;
116 skb_pull(skb, llc_len);
117 if (skb->protocol == htons(ETH_P_802_2)) {
118 u16 pdulen = eth_hdr(skb)->h_proto,
119 data_size = ntohs(pdulen) - llc_len;
121 if (unlikely(pskb_trim_rcsum(skb, data_size)))
122 return 0;
123 }
124 return 1;
125 }
127 /**
128 * llc_rcv - 802.2 entry point from net lower layers
129 * @skb: received pdu
130 * @dev: device that receive pdu
131 * @pt: packet type
132 *
133 * When the system receives a 802.2 frame this function is called. It
134 * checks SAP and connection of received pdu and passes frame to
135 * llc_{station,sap,conn}_rcv for sending to proper state machine. If
136 * the frame is related to a busy connection (a connection is sending
137 * data now), it queues this frame in the connection's backlog.
138 */
139 int llc_rcv(struct sk_buff *skb, struct net_device *dev,
140 struct packet_type *pt, struct net_device *orig_dev)
141 {
142 struct llc_sap *sap;
143 struct llc_pdu_sn *pdu;
144 int dest;
145 int (*rcv)(struct sk_buff *, struct net_device *,
146 struct packet_type *, struct net_device *);
148 /*
149 * When the interface is in promisc. mode, drop all the crap that it
150 * receives, do not try to analyse it.
151 */
152 if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
153 dprintk("%s: PACKET_OTHERHOST\n", __FUNCTION__);
154 goto drop;
155 }
156 skb = skb_share_check(skb, GFP_ATOMIC);
157 if (unlikely(!skb))
158 goto out;
159 if (unlikely(!llc_fixup_skb(skb)))
160 goto drop;
161 pdu = llc_pdu_sn_hdr(skb);
162 if (unlikely(!pdu->dsap)) /* NULL DSAP, refer to station */
163 goto handle_station;
164 sap = llc_sap_find(pdu->dsap);
165 if (unlikely(!sap)) {/* unknown SAP */
166 dprintk("%s: llc_sap_find(%02X) failed!\n", __FUNCTION__,
167 pdu->dsap);
168 goto drop;
169 }
170 /*
171 * First the upper layer protocols that don't need the full
172 * LLC functionality
173 */
174 rcv = rcu_dereference(sap->rcv_func);
175 if (rcv) {
176 struct sk_buff *cskb = skb_clone(skb, GFP_ATOMIC);
177 if (cskb)
178 rcv(cskb, dev, pt, orig_dev);
179 }
180 dest = llc_pdu_type(skb);
181 if (unlikely(!dest || !llc_type_handlers[dest - 1]))
182 goto drop_put;
183 llc_type_handlers[dest - 1](sap, skb);
184 out_put:
185 llc_sap_put(sap);
186 out:
187 return 0;
188 drop:
189 kfree_skb(skb);
190 goto out;
191 drop_put:
192 kfree_skb(skb);
193 goto out_put;
194 handle_station:
195 if (!llc_station_handler)
196 goto drop;
197 llc_station_handler(skb);
198 goto out;
199 }
201 EXPORT_SYMBOL(llc_add_pack);
202 EXPORT_SYMBOL(llc_remove_pack);
203 EXPORT_SYMBOL(llc_set_station_handler);