net: cosmetic: Fix checkpatch.pl failures in net.c
[platform/kernel/u-boot.git] / net / arp.c
1 /*
2  *      Copied from Linux Monitor (LiMon) - Networking.
3  *
4  *      Copyright 1994 - 2000 Neil Russell.
5  *      (See License)
6  *      Copyright 2000 Roland Borde
7  *      Copyright 2000 Paolo Scaffardi
8  *      Copyright 2000-2002 Wolfgang Denk, wd@denx.de
9  *      SPDX-License-Identifier:        GPL-2.0
10  */
11
12 #include <common.h>
13
14 #include "arp.h"
15
16 #ifndef CONFIG_ARP_TIMEOUT
17 /* Milliseconds before trying ARP again */
18 # define ARP_TIMEOUT            5000UL
19 #else
20 # define ARP_TIMEOUT            CONFIG_ARP_TIMEOUT
21 #endif
22
23
24 #ifndef CONFIG_NET_RETRY_COUNT
25 # define ARP_TIMEOUT_COUNT      5       /* # of timeouts before giving up  */
26 #else
27 # define ARP_TIMEOUT_COUNT      CONFIG_NET_RETRY_COUNT
28 #endif
29
30 struct in_addr net_arp_wait_packet_ip;
31 static struct in_addr net_arp_wait_reply_ip;
32 /* MAC address of waiting packet's destination */
33 uchar          *arp_wait_packet_ethaddr;
34 int             arp_wait_tx_packet_size;
35 ulong           arp_wait_timer_start;
36 int             arp_wait_try;
37
38 static uchar   *arp_tx_packet;  /* THE ARP transmit packet */
39 static uchar    arp_tx_packet_buf[PKTSIZE_ALIGN + PKTALIGN];
40
41 void arp_init(void)
42 {
43         /* XXX problem with bss workaround */
44         arp_wait_packet_ethaddr = NULL;
45         net_arp_wait_packet_ip.s_addr = 0;
46         net_arp_wait_reply_ip.s_addr = 0;
47         arp_wait_tx_packet_size = 0;
48         arp_tx_packet = &arp_tx_packet_buf[0] + (PKTALIGN - 1);
49         arp_tx_packet -= (ulong)arp_tx_packet % PKTALIGN;
50 }
51
52 void arp_raw_request(struct in_addr source_ip, const uchar *target_ethaddr,
53         struct in_addr target_ip)
54 {
55         uchar *pkt;
56         struct arp_hdr *arp;
57         int eth_hdr_size;
58
59         debug_cond(DEBUG_DEV_PKT, "ARP broadcast %d\n", arp_wait_try);
60
61         pkt = arp_tx_packet;
62
63         eth_hdr_size = net_set_ether(pkt, net_bcast_ethaddr, PROT_ARP);
64         pkt += eth_hdr_size;
65
66         arp = (struct arp_hdr *)pkt;
67
68         arp->ar_hrd = htons(ARP_ETHER);
69         arp->ar_pro = htons(PROT_IP);
70         arp->ar_hln = ARP_HLEN;
71         arp->ar_pln = ARP_PLEN;
72         arp->ar_op = htons(ARPOP_REQUEST);
73
74         memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN);    /* source ET addr */
75         net_write_ip(&arp->ar_spa, source_ip);          /* source IP addr */
76         memcpy(&arp->ar_tha, target_ethaddr, ARP_HLEN); /* target ET addr */
77         net_write_ip(&arp->ar_tpa, target_ip);          /* target IP addr */
78
79         net_send_packet(arp_tx_packet, eth_hdr_size + ARP_HDR_SIZE);
80 }
81
82 void arp_request(void)
83 {
84         if ((net_arp_wait_packet_ip.s_addr & net_netmask.s_addr) !=
85             (net_ip.s_addr & net_netmask.s_addr)) {
86                 if (net_gateway.s_addr == 0) {
87                         puts("## Warning: gatewayip needed but not set\n");
88                         net_arp_wait_reply_ip = net_arp_wait_packet_ip;
89                 } else {
90                         net_arp_wait_reply_ip = net_gateway;
91                 }
92         } else {
93                 net_arp_wait_reply_ip = net_arp_wait_packet_ip;
94         }
95
96         arp_raw_request(net_ip, net_null_ethaddr, net_arp_wait_reply_ip);
97 }
98
99 void arp_timeout_check(void)
100 {
101         ulong t;
102
103         if (!net_arp_wait_packet_ip.s_addr)
104                 return;
105
106         t = get_timer(0);
107
108         /* check for arp timeout */
109         if ((t - arp_wait_timer_start) > ARP_TIMEOUT) {
110                 arp_wait_try++;
111
112                 if (arp_wait_try >= ARP_TIMEOUT_COUNT) {
113                         puts("\nARP Retry count exceeded; starting again\n");
114                         arp_wait_try = 0;
115                         net_start_again();
116                 } else {
117                         arp_wait_timer_start = t;
118                         arp_request();
119                 }
120         }
121 }
122
123 void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
124 {
125         struct arp_hdr *arp;
126         struct in_addr reply_ip_addr;
127         uchar *pkt;
128         int eth_hdr_size;
129
130         /*
131          * We have to deal with two types of ARP packets:
132          * - REQUEST packets will be answered by sending  our
133          *   IP address - if we know it.
134          * - REPLY packates are expected only after we asked
135          *   for the TFTP server's or the gateway's ethernet
136          *   address; so if we receive such a packet, we set
137          *   the server ethernet address
138          */
139         debug_cond(DEBUG_NET_PKT, "Got ARP\n");
140
141         arp = (struct arp_hdr *)ip;
142         if (len < ARP_HDR_SIZE) {
143                 printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
144                 return;
145         }
146         if (ntohs(arp->ar_hrd) != ARP_ETHER)
147                 return;
148         if (ntohs(arp->ar_pro) != PROT_IP)
149                 return;
150         if (arp->ar_hln != ARP_HLEN)
151                 return;
152         if (arp->ar_pln != ARP_PLEN)
153                 return;
154
155         if (net_ip.s_addr == 0)
156                 return;
157
158         if (net_read_ip(&arp->ar_tpa).s_addr != net_ip.s_addr)
159                 return;
160
161         switch (ntohs(arp->ar_op)) {
162         case ARPOP_REQUEST:
163                 /* reply with our IP address */
164                 debug_cond(DEBUG_DEV_PKT, "Got ARP REQUEST, return our IP\n");
165                 pkt = (uchar *)et;
166                 eth_hdr_size = net_update_ether(et, et->et_src, PROT_ARP);
167                 pkt += eth_hdr_size;
168                 arp->ar_op = htons(ARPOP_REPLY);
169                 memcpy(&arp->ar_tha, &arp->ar_sha, ARP_HLEN);
170                 net_copy_ip(&arp->ar_tpa, &arp->ar_spa);
171                 memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN);
172                 net_copy_ip(&arp->ar_spa, &net_ip);
173
174 #ifdef CONFIG_CMD_LINK_LOCAL
175                 /*
176                  * Work-around for brain-damaged Cisco equipment with
177                  *   arp-proxy enabled.
178                  *
179                  *   If the requesting IP is not on our subnet, wait 5ms to
180                  *   reply to ARP request so that our reply will overwrite
181                  *   the arp-proxy's instead of the other way around.
182                  */
183                 if ((net_read_ip(&arp->ar_tpa).s_addr & net_netmask.s_addr) !=
184                     (net_read_ip(&arp->ar_spa).s_addr & net_netmask.s_addr))
185                         udelay(5000);
186 #endif
187                 net_send_packet((uchar *)et, eth_hdr_size + ARP_HDR_SIZE);
188                 return;
189
190         case ARPOP_REPLY:               /* arp reply */
191                 /* are we waiting for a reply */
192                 if (!net_arp_wait_packet_ip.s_addr)
193                         break;
194
195 #ifdef CONFIG_KEEP_SERVERADDR
196                 if (net_server_ip.s_addr == net_arp_wait_packet_ip.s_addr) {
197                         char buf[20];
198                         sprintf(buf, "%pM", &arp->ar_sha);
199                         setenv("serveraddr", buf);
200                 }
201 #endif
202
203                 reply_ip_addr = net_read_ip(&arp->ar_spa);
204
205                 /* matched waiting packet's address */
206                 if (reply_ip_addr.s_addr == net_arp_wait_reply_ip.s_addr) {
207                         debug_cond(DEBUG_DEV_PKT,
208                                    "Got ARP REPLY, set eth addr (%pM)\n",
209                                    arp->ar_data);
210
211                         /* save address for later use */
212                         if (arp_wait_packet_ethaddr != NULL)
213                                 memcpy(arp_wait_packet_ethaddr,
214                                        &arp->ar_sha, ARP_HLEN);
215
216                         net_get_arp_handler()((uchar *)arp, 0, reply_ip_addr,
217                                               0, len);
218
219                         /* set the mac address in the waiting packet's header
220                            and transmit it */
221                         memcpy(((struct ethernet_hdr *)net_tx_packet)->et_dest,
222                                &arp->ar_sha, ARP_HLEN);
223                         net_send_packet(net_tx_packet, arp_wait_tx_packet_size);
224
225                         /* no arp request pending now */
226                         net_arp_wait_packet_ip.s_addr = 0;
227                         arp_wait_tx_packet_size = 0;
228                         arp_wait_packet_ethaddr = NULL;
229                 }
230                 return;
231         default:
232                 debug("Unexpected ARP opcode 0x%x\n",
233                       ntohs(arp->ar_op));
234                 return;
235         }
236 }