net/fastboot_udp.c

   1 // SPDX-License-Identifier: BSD-2-Clause
   2 /*
   3  * Copyright (C) 2016 The Android Open Source Project
   4  */
   5
   6 #include <common.h>
   7 #include <command.h>
   8 #include <fastboot.h>
   9 #include <net.h>
  10 #include <net/fastboot_udp.h>
  11 #include <linux/printk.h>
  12
  13 enum {
  14         FASTBOOT_ERROR = 0,
  15         FASTBOOT_QUERY = 1,
  16         FASTBOOT_INIT = 2,
  17         FASTBOOT_FASTBOOT = 3,
  18 };
  19
  20 struct __packed fastboot_header {
  21         uchar id;
  22         uchar flags;
  23         unsigned short seq;
  24 };
  25
  26 #define PACKET_SIZE 1024
  27 #define DATA_SIZE (PACKET_SIZE - sizeof(struct fastboot_header))
  28
  29 /* Sequence number sent for every packet */
  30 static unsigned short sequence_number = 1;
  31 static const unsigned short packet_size = PACKET_SIZE;
  32 static const unsigned short udp_version = 1;
  33
  34 /* Keep track of last packet for resubmission */
  35 static uchar last_packet[PACKET_SIZE];
  36 static unsigned int last_packet_len;
  37
  38 static struct in_addr fastboot_remote_ip;
  39 /* The UDP port at their end */
  40 static int fastboot_remote_port;
  41 /* The UDP port at our end */
  42 static int fastboot_our_port;
  43
  44 /**
  45  * fastboot_udp_send_info() - Send an INFO packet during long commands.
  46  *
  47  * @msg: String describing the reason for waiting
  48  */
  49 static void fastboot_udp_send_info(const char *msg)
  50 {
  51         uchar *packet;
  52         uchar *packet_base;
  53         int len = 0;
  54         char response[FASTBOOT_RESPONSE_LEN] = {0};
  55
  56         struct fastboot_header response_header = {
  57                 .id = FASTBOOT_FASTBOOT,
  58                 .flags = 0,
  59                 .seq = htons(sequence_number)
  60         };
  61         ++sequence_number;
  62         packet = net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE;
  63         packet_base = packet;
  64
  65         /* Write headers */
  66         memcpy(packet, &response_header, sizeof(response_header));
  67         packet += sizeof(response_header);
  68         /* Write response */
  69         fastboot_response("INFO", response, "%s", msg);
  70         memcpy(packet, response, strlen(response));
  71         packet += strlen(response);
  72
  73         len = packet - packet_base;
  74
  75         /* Save packet for retransmitting */
  76         last_packet_len = len;
  77         memcpy(last_packet, packet_base, last_packet_len);
  78
  79         net_send_udp_packet(net_server_ethaddr, fastboot_remote_ip,
  80                             fastboot_remote_port, fastboot_our_port, len);
  81 }
  82
  83 /**
  84  * fastboot_timed_send_info() - Send INFO packet every 30 seconds
  85  *
  86  * @msg: String describing the reason for waiting
  87  *
  88  * Send an INFO packet during long commands based on timer. An INFO packet
  89  * is sent if the time is 30 seconds after start. Else, noop.
  90  */
  91 static void fastboot_timed_send_info(const char *msg)
  92 {
  93         static ulong start;
  94
  95         /* Initialize timer */
  96         if (start == 0)
  97                 start = get_timer(0);
  98         ulong time = get_timer(start);
  99         /* Send INFO packet to host every 30 seconds */
 100         if (time >= 30000) {
 101                 start = get_timer(0);
 102                 fastboot_udp_send_info(msg);
 103         }
 104 }
 105
 106 /**
 107  * fastboot_send() - Sends a packet in response to received fastboot packet
 108  *
 109  * @header: Header for response packet
 110  * @fastboot_data: Pointer to received fastboot data
 111  * @fastboot_data_len: Length of received fastboot data
 112  * @retransmit: Nonzero if sending last sent packet
 113  */
 114 static void fastboot_send(struct fastboot_header header, char *fastboot_data,
 115                           unsigned int fastboot_data_len, uchar retransmit)
 116 {
 117         uchar *packet;
 118         uchar *packet_base;
 119         int len = 0;
 120         const char *error_msg = "An error occurred.";
 121         short tmp;
 122         struct fastboot_header response_header = header;
 123         static char command[FASTBOOT_COMMAND_LEN];
 124         static int cmd = -1;
 125         static bool pending_command;
 126         char response[FASTBOOT_RESPONSE_LEN] = {0};
 127
 128         /*
 129          * We will always be sending some sort of packet, so
 130          * cobble together the packet headers now.
 131          */
 132         packet = net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE;
 133         packet_base = packet;
 134
 135         /* Resend last packet */
 136         if (retransmit) {
 137                 memcpy(packet, last_packet, last_packet_len);
 138                 net_send_udp_packet(net_server_ethaddr, fastboot_remote_ip,
 139                                     fastboot_remote_port, fastboot_our_port,
 140                                     last_packet_len);
 141                 return;
 142         }
 143
 144         response_header.seq = htons(response_header.seq);
 145         memcpy(packet, &response_header, sizeof(response_header));
 146         packet += sizeof(response_header);
 147
 148         switch (header.id) {
 149         case FASTBOOT_QUERY:
 150                 tmp = htons(sequence_number);
 151                 memcpy(packet, &tmp, sizeof(tmp));
 152                 packet += sizeof(tmp);
 153                 break;
 154         case FASTBOOT_INIT:
 155                 tmp = htons(udp_version);
 156                 memcpy(packet, &tmp, sizeof(tmp));
 157                 packet += sizeof(tmp);
 158                 tmp = htons(packet_size);
 159                 memcpy(packet, &tmp, sizeof(tmp));
 160                 packet += sizeof(tmp);
 161                 break;
 162         case FASTBOOT_ERROR:
 163                 memcpy(packet, error_msg, strlen(error_msg));
 164                 packet += strlen(error_msg);
 165                 break;
 166         case FASTBOOT_FASTBOOT:
 167                 if (cmd == FASTBOOT_COMMAND_DOWNLOAD) {
 168                         if (!fastboot_data_len && !fastboot_data_remaining()) {
 169                                 fastboot_data_complete(response);
 170                         } else {
 171                                 fastboot_data_download(fastboot_data,
 172                                                        fastboot_data_len,
 173                                                        response);
 174                         }
 175                 } else if (!pending_command) {
 176                         strlcpy(command, fastboot_data,
 177                                 min((size_t)fastboot_data_len + 1,
 178                                     sizeof(command)));
 179                         pending_command = true;
 180                 } else {
 181                         cmd = fastboot_handle_command(command, response);
 182                         pending_command = false;
 183                 }
 184                 /*
 185                  * Sent some INFO packets, need to update sequence number in
 186                  * header
 187                  */
 188                 if (header.seq != sequence_number) {
 189                         response_header.seq = htons(sequence_number);
 190                         memcpy(packet_base, &response_header,
 191                                sizeof(response_header));
 192                 }
 193                 /* Write response to packet */
 194                 memcpy(packet, response, strlen(response));
 195                 packet += strlen(response);
 196                 break;
 197         default:
 198                 pr_err("ID %d not implemented.\n", header.id);
 199                 return;
 200         }
 201
 202         len = packet - packet_base;
 203
 204         /* Save packet for retransmitting */
 205         last_packet_len = len;
 206         memcpy(last_packet, packet_base, last_packet_len);
 207
 208         net_send_udp_packet(net_server_ethaddr, fastboot_remote_ip,
 209                             fastboot_remote_port, fastboot_our_port, len);
 210
 211         fastboot_handle_boot(cmd, strncmp("OKAY", response, 4) == 0);
 212
 213         if (!strncmp("OKAY", response, 4) || !strncmp("FAIL", response, 4))
 214                 cmd = -1;
 215 }
 216
 217 /**
 218  * fastboot_handler() - Incoming UDP packet handler.
 219  *
 220  * @packet: Pointer to incoming UDP packet
 221  * @dport: Destination UDP port
 222  * @sip: Source IP address
 223  * @sport: Source UDP port
 224  * @len: Packet length
 225  */
 226 static void fastboot_handler(uchar *packet, unsigned int dport,
 227                              struct in_addr sip, unsigned int sport,
 228                              unsigned int len)
 229 {
 230         struct fastboot_header header;
 231         char fastboot_data[DATA_SIZE] = {0};
 232         unsigned int fastboot_data_len = 0;
 233
 234         if (dport != fastboot_our_port)
 235                 return;
 236
 237         fastboot_remote_ip = sip;
 238         fastboot_remote_port = sport;
 239
 240         if (len < sizeof(struct fastboot_header) || len > PACKET_SIZE)
 241                 return;
 242         memcpy(&header, packet, sizeof(header));
 243         header.flags = 0;
 244         header.seq = ntohs(header.seq);
 245         packet += sizeof(header);
 246         len -= sizeof(header);
 247
 248         switch (header.id) {
 249         case FASTBOOT_QUERY:
 250                 fastboot_send(header, fastboot_data, 0, 0);
 251                 break;
 252         case FASTBOOT_INIT:
 253         case FASTBOOT_FASTBOOT:
 254                 fastboot_data_len = len;
 255                 if (len > 0)
 256                         memcpy(fastboot_data, packet, len);
 257                 if (header.seq == sequence_number) {
 258                         fastboot_send(header, fastboot_data,
 259                                       fastboot_data_len, 0);
 260                         sequence_number++;
 261                 } else if (header.seq == sequence_number - 1) {
 262                         /* Retransmit last sent packet */
 263                         fastboot_send(header, fastboot_data,
 264                                       fastboot_data_len, 1);
 265                 }
 266                 break;
 267         default:
 268                 pr_err("ID %d not implemented.\n", header.id);
 269                 header.id = FASTBOOT_ERROR;
 270                 fastboot_send(header, fastboot_data, 0, 0);
 271                 break;
 272         }
 273 }
 274
 275 void fastboot_udp_start_server(void)
 276 {
 277         printf("Using %s device\n", eth_get_name());
 278         printf("Listening for fastboot command on %pI4\n", &net_ip);
 279
 280         fastboot_our_port = CONFIG_UDP_FUNCTION_FASTBOOT_PORT;
 281
 282         if (IS_ENABLED(CONFIG_FASTBOOT_FLASH))
 283                 fastboot_set_progress_callback(fastboot_timed_send_info);
 284
 285         net_set_udp_handler(fastboot_handler);
 286
 287         /* zero out server ether in case the server ip has changed */
 288         memset(net_server_ethaddr, 0, 6);
 289 }