[PATCH 16/20] fastboot net: implement fastboot over UDP
Sascha Hauer
s.hauer at pengutronix.de
Thu Aug 13 09:42:53 EDT 2020
From: Edmund Henniges <eh at emlix.com>
This implements the UDP variant of the fastboot protocol. The only way to
start the service for now is to compile with CONFIG_FASTBOOT_NET_ON_BOOT.
The service will bind to the network interface that provides the IPv4
gateway.
Sending an OKAY packet before performing a restart is necessary since
contrary to USB the host will not notice when a UDP server disappears.
Signed-off-by: Edmund Henniges <eh at emlix.com>
Signed-off-by: Daniel Glöckner <dg at emlix.com>
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
common/fastboot.c | 3 +
include/fastboot.h | 3 +
include/fastboot_net.h | 12 +
net/Kconfig | 10 +
net/Makefile | 1 +
net/fastboot.c | 580 +++++++++++++++++++++++++++++++++++++++++
6 files changed, 609 insertions(+)
create mode 100644 include/fastboot_net.h
create mode 100644 net/fastboot.c
diff --git a/common/fastboot.c b/common/fastboot.c
index 3f61208a21..d737107d19 100644
--- a/common/fastboot.c
+++ b/common/fastboot.c
@@ -245,6 +245,7 @@ static char *fastboot_msg[] = {
[FASTBOOT_MSG_FAIL] = "FAIL",
[FASTBOOT_MSG_INFO] = "INFO",
[FASTBOOT_MSG_DATA] = "DATA",
+ [FASTBOOT_MSG_NONE] = "",
};
int fastboot_tx_print(struct fastboot *fb, enum fastboot_msg_type type,
@@ -273,6 +274,7 @@ int fastboot_tx_print(struct fastboot *fb, enum fastboot_msg_type type,
case FASTBOOT_MSG_INFO:
pr_info("%pV\n", &vaf);
break;
+ case FASTBOOT_MSG_NONE:
case FASTBOOT_MSG_DATA:
break;
}
@@ -287,6 +289,7 @@ int fastboot_tx_print(struct fastboot *fb, enum fastboot_msg_type type,
static void cb_reboot(struct fastboot *fb, const char *cmd)
{
+ fastboot_tx_print(fb, FASTBOOT_MSG_OKAY, "");
restart_machine();
}
diff --git a/include/fastboot.h b/include/fastboot.h
index 7718390ae5..fa826a1622 100644
--- a/include/fastboot.h
+++ b/include/fastboot.h
@@ -5,6 +5,8 @@
#include <file-list.h>
#include <net.h>
+#define FASTBOOT_MAX_CMD_LEN 64
+
/*
* Return codes for the exec_cmd callback above:
*
@@ -51,6 +53,7 @@ enum fastboot_msg_type {
FASTBOOT_MSG_FAIL,
FASTBOOT_MSG_INFO,
FASTBOOT_MSG_DATA,
+ FASTBOOT_MSG_NONE,
};
extern int fastboot_bbu;
diff --git a/include/fastboot_net.h b/include/fastboot_net.h
new file mode 100644
index 0000000000..e4b9d98091
--- /dev/null
+++ b/include/fastboot_net.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef __FASTBOOT_NET__
+#define __FASTBOOT_NET__
+
+#include <fastboot.h>
+
+struct fastboot_net;
+
+struct fastboot_net *fastboot_net_init(struct fastboot_opts *opts);
+void fastboot_net_free(struct fastboot_net *fbn);
+
+#endif
diff --git a/net/Kconfig b/net/Kconfig
index 12b6bdb56d..a3c8c10f33 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -31,4 +31,14 @@ config NET_SNTP
bool
prompt "sntp support"
+config NET_FASTBOOT
+ bool
+ select BANNER
+ select FILE_LIST
+ select FASTBOOT_BASE
+ prompt "Android Fastboot support"
+ help
+ This option adds support for the UDP variant of the Fastboot
+ protocol.
+
endif
diff --git a/net/Makefile b/net/Makefile
index eb8d439150..962b2dec58 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_CMD_PING) += ping.o
obj-$(CONFIG_NET_RESOLV)+= dns.o
obj-$(CONFIG_NET_NETCONSOLE) += netconsole.o
obj-$(CONFIG_NET_IFUP) += ifup.o
+obj-$(CONFIG_NET_FASTBOOT) += fastboot.o
diff --git a/net/fastboot.c b/net/fastboot.c
new file mode 100644
index 0000000000..9c65b5c0b1
--- /dev/null
+++ b/net/fastboot.c
@@ -0,0 +1,580 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Copyright 2020 Edmund Henniges <eh at emlix.com>
+ * Copyright 2020 Daniel Glöckner <dg at emlix.com>
+ * Ported from U-Boot to Barebox
+ */
+
+#define pr_fmt(fmt) "net fastboot: " fmt
+
+#include <common.h>
+#include <net.h>
+#include <fastboot.h>
+#include <fastboot_net.h>
+#include <environment.h>
+#include <progress.h>
+#include <unistd.h>
+#include <init.h>
+#include <work.h>
+#include <globalvar.h>
+#include <magicvar.h>
+
+#define FASTBOOT_PORT 5554
+#define MAX_MTU 1500
+#define PACKET_SIZE (min(PKTSIZE, MAX_MTU + ETHER_HDR_SIZE) \
+ - (net_eth_to_udp_payload(0) - (char *)0))
+
+enum {
+ FASTBOOT_ERROR = 0,
+ FASTBOOT_QUERY = 1,
+ FASTBOOT_INIT = 2,
+ FASTBOOT_FASTBOOT = 3,
+};
+
+enum may_send {
+ MAY_NOT_SEND,
+ MAY_SEND_MESSAGE,
+ MAY_SEND_ACK,
+};
+
+struct __packed fastboot_header {
+ u8 id;
+ u8 flags;
+ u16 seq;
+};
+
+#define FASTBOOT_MAX_MSG_LEN 64
+
+struct fastboot_net {
+ struct fastboot fastboot;
+
+ struct net_connection *net_con;
+ struct fastboot_header response_header;
+ struct poller_struct poller;
+ struct work_queue wq;
+ u64 host_waits_since;
+ u64 last_download_pkt;
+ bool sequence_number_seen;
+ bool active_download;
+ bool reinit;
+ bool send_keep_alive;
+ enum may_send may_send;
+
+ IPaddr_t host_addr;
+ u16 host_port;
+ u8 host_mac[ETH_ALEN];
+ u16 sequence_number;
+ u16 last_payload_len;
+ void *last_payload;
+};
+
+static const ushort udp_version = 1;
+
+static bool is_current_connection(struct fastboot_net *fbn)
+{
+ return fbn->host_addr == net_read_ip(&fbn->net_con->ip->daddr) &&
+ fbn->host_port == fbn->net_con->udp->uh_dport;
+}
+
+static void fastboot_net_abort(struct fastboot_net *fbn)
+{
+ fbn->reinit = true;
+
+ fastboot_abort(&fbn->fastboot);
+
+ fbn->active_download = false;
+
+ poller_unregister(&fbn->poller);
+
+ /*
+ * If the host sends a data packet at a time when an empty packet was
+ * expected, fastboot_abort is called and an error message is sent.
+ * We don't want to execute the contents of the bad packet afterwards.
+ * Clearing command also tells our keep-alive poller to stop sending
+ * messages.
+ */
+ wq_cancel_work(&fbn->wq);
+
+ free(fbn->last_payload);
+ fbn->last_payload = NULL;
+}
+
+static void fastboot_net_save_payload(struct fastboot_net *fbn, void *packet,
+ int len)
+{
+ /* Save packet for retransmitting */
+
+ fbn->last_payload_len = len;
+ free(fbn->last_payload);
+ fbn->last_payload = memdup(packet, len);
+}
+
+static void fastboot_send(struct fastboot_net *fbn,
+ struct fastboot_header header,
+ const char *error_msg)
+{
+ short tmp;
+ uchar *packet = net_udp_get_payload(fbn->net_con);
+ uchar *packet_base = packet;
+ bool current_session = false;
+
+ if (fbn->sequence_number == ntohs(header.seq) &&
+ is_current_connection(fbn))
+ current_session = true;
+
+ if (error_msg)
+ header.id = FASTBOOT_ERROR;
+
+ /* send header */
+ memcpy(packet, &header, sizeof(header));
+ packet += sizeof(header);
+
+ switch (header.id) {
+ case FASTBOOT_QUERY:
+ /* send sequence number */
+ tmp = htons(fbn->sequence_number);
+ memcpy(packet, &tmp, sizeof(tmp));
+ packet += sizeof(tmp);
+ break;
+ case FASTBOOT_INIT:
+ /* send udp version and packet size */
+ tmp = htons(udp_version);
+ memcpy(packet, &tmp, sizeof(tmp));
+ packet += sizeof(tmp);
+ tmp = htons(PACKET_SIZE);
+ memcpy(packet, &tmp, sizeof(tmp));
+ packet += sizeof(tmp);
+ break;
+ case FASTBOOT_ERROR:
+ pr_err("%s\n", error_msg);
+
+ /* send error message */
+ tmp = strlen(error_msg);
+ memcpy(packet, error_msg, tmp);
+ packet += tmp;
+
+ if (current_session)
+ fastboot_net_abort(fbn);
+
+ break;
+ }
+
+ if (current_session && header.id != FASTBOOT_QUERY) {
+ fbn->sequence_number++;
+ fbn->sequence_number_seen = false;
+ fastboot_net_save_payload(fbn, packet_base, packet - packet_base);
+ }
+ net_udp_send(fbn->net_con, packet - packet_base);
+}
+
+static int fastboot_net_wait_may_send(struct fastboot_net *fbn)
+{
+ uint64_t start = get_time_ns();
+
+ while (!is_timeout(start, 2 * SECOND)) {
+ if (fbn->may_send != MAY_NOT_SEND)
+ return 0;
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int fastboot_write_net(struct fastboot *fb, const char *buf,
+ unsigned int n)
+{
+ struct fastboot_net *fbn = container_of(fb, struct fastboot_net,
+ fastboot);
+ struct fastboot_header response_header;
+ uchar *packet;
+ uchar *packet_base;
+ int ret;
+
+ if (fbn->reinit)
+ return 0;
+
+ /*
+ * This function is either called in command context, in which
+ * case we may wait, or from the keepalive poller which explicitly
+ * only calls us when we don't have to wait here.
+ */
+ ret = fastboot_net_wait_may_send(fbn);
+ if (ret) {
+ fastboot_net_abort(fbn);
+ return ret;
+ }
+
+ if (n && fbn->may_send == MAY_SEND_ACK) {
+ fastboot_send(fbn, fbn->response_header,
+ "Have message but only ACK allowed");
+ return -EPROTO;
+ } else if (!n && fbn->may_send == MAY_SEND_MESSAGE) {
+ fastboot_send(fbn, fbn->response_header,
+ "Want to send ACK but message expected");
+ return -EPROTO;
+ }
+
+ response_header = fbn->response_header;
+ response_header.flags = 0;
+ response_header.seq = htons(fbn->sequence_number);
+ ++fbn->sequence_number;
+ fbn->sequence_number_seen = false;
+
+ packet = net_udp_get_payload(fbn->net_con);
+ packet_base = packet;
+
+ /* Write headers */
+ memcpy(packet, &response_header, sizeof(response_header));
+ packet += sizeof(response_header);
+ /* Write response */
+ memcpy(packet, buf, n);
+ packet += n;
+
+ fastboot_net_save_payload(fbn, packet_base, packet - packet_base);
+
+ memcpy(fbn->net_con->et->et_dest, fbn->host_mac, ETH_ALEN);
+ net_write_ip(&fbn->net_con->ip->daddr, fbn->host_addr);
+ fbn->net_con->udp->uh_dport = fbn->host_port;
+
+ fbn->may_send = MAY_NOT_SEND;
+
+ net_udp_send(fbn->net_con, fbn->last_payload_len);
+
+ return 0;
+}
+
+static void fastboot_start_download_net(struct fastboot *fb)
+{
+ struct fastboot_net *fbn = container_of(fb, struct fastboot_net,
+ fastboot);
+
+ fastboot_start_download_generic(fb);
+ fbn->active_download = true;
+ fbn->last_download_pkt = get_time_ns();
+}
+
+/* must send exactly one packet on all code paths */
+static void fastboot_data_download(struct fastboot_net *fbn,
+ const void *fastboot_data,
+ unsigned int fastboot_data_len)
+{
+ int ret;
+
+ if (fastboot_data_len == 0 ||
+ (fbn->fastboot.download_bytes + fastboot_data_len) >
+ fbn->fastboot.download_size) {
+ fastboot_send(fbn, fbn->response_header,
+ "Received invalid data length");
+ return;
+ }
+
+ ret = fastboot_handle_download_data(&fbn->fastboot, fastboot_data,
+ fastboot_data_len);
+ if (ret < 0) {
+ fastboot_send(fbn, fbn->response_header, strerror(-ret));
+ return;
+ }
+
+ fastboot_tx_print(&fbn->fastboot, FASTBOOT_MSG_NONE, "");
+}
+
+struct fastboot_work {
+ struct work_struct work;
+ struct fastboot_net *fbn;
+ bool download_finished;
+ char command[FASTBOOT_MAX_CMD_LEN + 1];
+};
+
+static void fastboot_handle_type_fastboot(struct fastboot_net *fbn,
+ struct fastboot_header header,
+ char *fastboot_data,
+ unsigned int fastboot_data_len)
+{
+ struct fastboot_work *w;
+
+ fbn->response_header = header;
+ fbn->host_waits_since = get_time_ns();
+ fbn->may_send = fastboot_data_len ? MAY_SEND_ACK : MAY_SEND_MESSAGE;
+
+ if (fbn->active_download) {
+ fbn->last_download_pkt = get_time_ns();
+
+ if (!fastboot_data_len && fbn->fastboot.download_bytes
+ == fbn->fastboot.download_size) {
+
+ fbn->active_download = false;
+
+ w = xzalloc(sizeof(*w));
+ w->fbn = fbn;
+ w->download_finished = true;
+
+ wq_queue_work(&fbn->wq, &w->work);
+ } else {
+ fastboot_data_download(fbn, fastboot_data,
+ fastboot_data_len);
+ }
+ return;
+ }
+
+ if (fastboot_data_len > FASTBOOT_MAX_CMD_LEN) {
+ fastboot_send(fbn, header, "command too long");
+ return;
+ }
+
+ if (!list_empty(&fbn->wq.work))
+ return;
+
+ if (fastboot_data_len) {
+ w = xzalloc(sizeof(*w));
+ w->fbn = fbn;
+ memcpy(w->command, fastboot_data, fastboot_data_len);
+ w->command[fastboot_data_len] = 0;
+
+ wq_queue_work(&fbn->wq, &w->work);
+ }
+}
+
+static void fastboot_check_retransmit(struct fastboot_net *fbn,
+ struct fastboot_header header)
+{
+ if (ntohs(header.seq) == fbn->sequence_number - 1 &&
+ is_current_connection(fbn)) {
+ /* Retransmit last sent packet */
+ memcpy(net_udp_get_payload(fbn->net_con),
+ fbn->last_payload, fbn->last_payload_len);
+ net_udp_send(fbn->net_con, fbn->last_payload_len);
+ }
+}
+
+static void fastboot_handler(void *ctx, char *packet, unsigned int raw_len)
+{
+ unsigned int len = net_eth_to_udplen(packet);
+ struct ethernet *eth_header = (struct ethernet *)packet;
+ struct iphdr *ip_header = net_eth_to_iphdr(packet);
+ struct udphdr *udp_header = net_eth_to_udphdr(packet);
+ char *payload = net_eth_to_udp_payload(packet);
+ struct fastboot_net *fbn = ctx;
+ struct fastboot_header header;
+ char *fastboot_data = payload + sizeof(header);
+ u16 tot_len = ntohs(ip_header->tot_len);
+ int ret;
+
+ /* catch bogus tot_len values */
+ if ((char *)ip_header - packet + tot_len > raw_len)
+ return;
+
+ /* catch packets split into fragments that are too small to reply */
+ if (fastboot_data - (char *)ip_header > tot_len)
+ return;
+
+ /* catch packets too small to be valid */
+ if (len < sizeof(struct fastboot_header))
+ return;
+
+ memcpy(&header, payload, sizeof(header));
+ header.flags = 0;
+ len -= sizeof(header);
+
+ /* catch remaining fragmented packets */
+ if (fastboot_data - (char *)ip_header + len > tot_len) {
+ fastboot_send(fbn, header,
+ "can't reassemble fragmented frames");
+ return;
+ }
+ /* catch too large packets */
+ if (len > PACKET_SIZE) {
+ fastboot_send(fbn, header, "packet too large");
+ return;
+ }
+
+ memcpy(fbn->net_con->et->et_dest, eth_header->et_src, ETH_ALEN);
+ net_copy_ip(&fbn->net_con->ip->daddr, &ip_header->saddr);
+ fbn->net_con->udp->uh_dport = udp_header->uh_sport;
+
+ switch (header.id) {
+ case FASTBOOT_QUERY:
+ fastboot_send(fbn, header, NULL);
+ break;
+ case FASTBOOT_INIT:
+ if (ntohs(header.seq) != fbn->sequence_number) {
+ fastboot_check_retransmit(fbn, header);
+ break;
+ }
+ fbn->host_addr = net_read_ip(&ip_header->saddr);
+ fbn->host_port = udp_header->uh_sport;
+ memcpy(fbn->host_mac, eth_header->et_src, ETH_ALEN);
+ fastboot_net_abort(fbn);
+ /* poller just unregistered in fastboot_net_abort() */
+ ret = poller_register(&fbn->poller, "fastboot");
+ if (ret) {
+ pr_err("Cannot register poller: %s\n", strerror(-ret));
+ return;
+ }
+ fastboot_send(fbn, header, NULL);
+ break;
+ case FASTBOOT_FASTBOOT:
+ if (!is_current_connection(fbn))
+ break;
+ memcpy(fbn->host_mac, eth_header->et_src, ETH_ALEN);
+
+ if (ntohs(header.seq) != fbn->sequence_number) {
+ fastboot_check_retransmit(fbn, header);
+ } else if (!fbn->sequence_number_seen) {
+ fbn->sequence_number_seen = true;
+ fastboot_handle_type_fastboot(fbn, header,
+ fastboot_data, len);
+ }
+ break;
+ default:
+ fastboot_send(fbn, header, "unknown packet type");
+ break;
+ }
+}
+
+static void fastboot_do_work(struct work_struct *w)
+{
+ struct fastboot_work *fw = container_of(w, struct fastboot_work, work);
+ struct fastboot_net *fbn = fw->fbn;
+
+ if (fw->download_finished) {
+ fastboot_download_finished(&fbn->fastboot);
+ goto out;
+ }
+
+ fbn->reinit = false;
+ fastboot_tx_print(&fbn->fastboot, FASTBOOT_MSG_NONE, "");
+
+ fbn->send_keep_alive = true;
+
+ fastboot_exec_cmd(&fbn->fastboot, fw->command);
+ fbn->send_keep_alive = false;
+out:
+ free(fw);
+}
+
+static void fastboot_work_cancel(struct work_struct *w)
+{
+ struct fastboot_work *fw = container_of(w, struct fastboot_work, work);
+
+ free(fw);
+}
+
+static void fastboot_poll(struct poller_struct *poller)
+{
+ struct fastboot_net *fbn = container_of(poller, struct fastboot_net,
+ poller);
+
+ if (fbn->active_download && is_timeout(fbn->last_download_pkt,
+ 5 * SECOND)) {
+ pr_err("No progress for 5s, aborting\n");
+ fastboot_net_abort(fbn);
+ return;
+ }
+
+ if (!fbn->send_keep_alive)
+ return;
+
+ if (!is_timeout(fbn->host_waits_since, 30ULL * SECOND))
+ return;
+
+ if (fbn->may_send != MAY_SEND_MESSAGE)
+ return;
+
+ fastboot_tx_print(&fbn->fastboot, FASTBOOT_MSG_INFO, "still busy");
+}
+
+void fastboot_net_free(struct fastboot_net *fbn)
+{
+ fastboot_generic_close(&fbn->fastboot);
+ net_unregister(fbn->net_con);
+ fastboot_generic_free(&fbn->fastboot);
+ wq_unregister(&fbn->wq);
+ free(fbn->last_payload);
+ free(fbn);
+}
+
+struct fastboot_net *fastboot_net_init(struct fastboot_opts *opts)
+{
+ struct fastboot_net *fbn;
+ int ret;
+
+ fbn = xzalloc(sizeof(*fbn));
+ fbn->fastboot.write = fastboot_write_net;
+ fbn->fastboot.start_download = fastboot_start_download_net;
+
+ if (opts) {
+ fbn->fastboot.files = opts->files;
+ fbn->fastboot.cmd_exec = opts->cmd_exec;
+ fbn->fastboot.cmd_flash = opts->cmd_flash;
+ ret = fastboot_generic_init(&fbn->fastboot, opts->export_bbu);
+ } else {
+ fbn->fastboot.files = file_list_parse(fastboot_partitions
+ ? fastboot_partitions
+ : "");
+ ret = fastboot_generic_init(&fbn->fastboot, fastboot_bbu);
+ }
+ if (ret)
+ goto fail_generic_init;
+
+ fbn->net_con = net_udp_new(IP_BROADCAST, FASTBOOT_PORT,
+ fastboot_handler, fbn);
+ if (IS_ERR(fbn->net_con)) {
+ ret = PTR_ERR(fbn->net_con);
+ goto fail_net_con;
+ }
+ net_udp_bind(fbn->net_con, FASTBOOT_PORT);
+
+ eth_open(fbn->net_con->edev);
+
+ fbn->poller.func = fastboot_poll;
+
+ fbn->wq.fn = fastboot_do_work;
+ fbn->wq.cancel = fastboot_work_cancel;
+
+ wq_register(&fbn->wq);
+
+ return fbn;
+
+fail_net_con:
+ fastboot_generic_free(&fbn->fastboot);
+fail_generic_init:
+ free(fbn);
+ return ERR_PTR(ret);
+}
+
+static struct fastboot_net *fastboot_net_obj;
+static int fastboot_net_autostart;
+
+static int fastboot_on_boot(void)
+{
+ struct fastboot_net *fbn;
+
+ globalvar_add_simple_bool("fastboot.net.autostart",
+ &fastboot_net_autostart);
+
+ if (!fastboot_net_autostart)
+ return 0;
+
+ ifup_all(0);
+ fbn = fastboot_net_init(NULL);
+
+ if (IS_ERR(fbn))
+ return PTR_ERR(fbn);
+
+ fastboot_net_obj = fbn;
+ return 0;
+}
+
+static void fastboot_net_exit(void)
+{
+ if (fastboot_net_obj)
+ fastboot_net_free(fastboot_net_obj);
+}
+
+postenvironment_initcall(fastboot_on_boot);
+predevshutdown_exitcall(fastboot_net_exit);
+
+BAREBOX_MAGICVAR_NAMED(global_fastboot_net_autostart,
+ global.fastboot.net.autostart,
+ "If true, automatically start fastboot over UDP during startup");
--
2.28.0
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