1 files changed, 1081 insertions, 0 deletions

diff --git a/minadbd/transport.c b/minadbd/transport.c
new file mode 100644
index 000000000..2f7bd2784
--- /dev/null
+++ b/minadbd/transport.c
@@ -0,0 +1,1081 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include "sysdeps.h"
+
+#define   TRACE_TAG  TRACE_TRANSPORT
+#include "adb.h"
+
+static void transport_unref(atransport *t);
+
+static atransport transport_list = {
+    .next = &transport_list,
+    .prev = &transport_list,
+};
+
+ADB_MUTEX_DEFINE( transport_lock );
+
+#if ADB_TRACE
+#define MAX_DUMP_HEX_LEN 16
+static void  dump_hex( const unsigned char*  ptr, size_t  len )
+{
+    int  nn, len2 = len;
+    // Build a string instead of logging each character.
+    // MAX chars in 2 digit hex, one space, MAX chars, one '\0'.
+    char buffer[MAX_DUMP_HEX_LEN *2 + 1 + MAX_DUMP_HEX_LEN + 1 ], *pb = buffer;
+
+    if (len2 > MAX_DUMP_HEX_LEN) len2 = MAX_DUMP_HEX_LEN;
+
+    for (nn = 0; nn < len2; nn++) {
+        sprintf(pb, "%02x", ptr[nn]);
+        pb += 2;
+    }
+    sprintf(pb++, " ");
+
+    for (nn = 0; nn < len2; nn++) {
+        int  c = ptr[nn];
+        if (c < 32 || c > 127)
+            c = '.';
+        *pb++ =  c;
+    }
+    *pb++ = '\0';
+    DR("%s\n", buffer);
+}
+#endif
+
+void
+kick_transport(atransport*  t)
+{
+    if (t && !t->kicked)
+    {
+        int  kicked;
+
+        adb_mutex_lock(&transport_lock);
+        kicked = t->kicked;
+        if (!kicked)
+            t->kicked = 1;
+        adb_mutex_unlock(&transport_lock);
+
+        if (!kicked)
+            t->kick(t);
+    }
+}
+
+void
+run_transport_disconnects(atransport*  t)
+{
+    adisconnect*  dis = t->disconnects.next;
+
+    D("%s: run_transport_disconnects\n", t->serial);
+    while (dis != &t->disconnects) {
+        adisconnect*  next = dis->next;
+        dis->func( dis->opaque, t );
+        dis = next;
+    }
+}
+
+#if ADB_TRACE
+static void
+dump_packet(const char* name, const char* func, apacket* p)
+{
+    unsigned  command = p->msg.command;
+    int       len     = p->msg.data_length;
+    char      cmd[9];
+    char      arg0[12], arg1[12];
+    int       n;
+
+    for (n = 0; n < 4; n++) {
+        int  b = (command >> (n*8)) & 255;
+        if (b < 32 || b >= 127)
+            break;
+        cmd[n] = (char)b;
+    }
+    if (n == 4) {
+        cmd[4] = 0;
+    } else {
+        /* There is some non-ASCII name in the command, so dump
+            * the hexadecimal value instead */
+        snprintf(cmd, sizeof cmd, "%08x", command);
+    }
+
+    if (p->msg.arg0 < 256U)
+        snprintf(arg0, sizeof arg0, "%d", p->msg.arg0);
+    else
+        snprintf(arg0, sizeof arg0, "0x%x", p->msg.arg0);
+
+    if (p->msg.arg1 < 256U)
+        snprintf(arg1, sizeof arg1, "%d", p->msg.arg1);
+    else
+        snprintf(arg1, sizeof arg1, "0x%x", p->msg.arg1);
+
+    D("%s: %s: [%s] arg0=%s arg1=%s (len=%d) ",
+        name, func, cmd, arg0, arg1, len);
+    dump_hex(p->data, len);
+}
+#endif /* ADB_TRACE */
+
+static int
+read_packet(int  fd, const char* name, apacket** ppacket)
+{
+    char *p = (char*)ppacket;  /* really read a packet address */
+    int   r;
+    int   len = sizeof(*ppacket);
+    char  buff[8];
+    if (!name) {
+        snprintf(buff, sizeof buff, "fd=%d", fd);
+        name = buff;
+    }
+    while(len > 0) {
+        r = adb_read(fd, p, len);
+        if(r > 0) {
+            len -= r;
+            p   += r;
+        } else {
+            D("%s: read_packet (fd=%d), error ret=%d errno=%d: %s\n", name, fd, r, errno, strerror(errno));
+            if((r < 0) && (errno == EINTR)) continue;
+            return -1;
+        }
+    }
+
+#if ADB_TRACE
+    if (ADB_TRACING) {
+        dump_packet(name, "from remote", *ppacket);
+    }
+#endif
+    return 0;
+}
+
+static int
+write_packet(int  fd, const char* name, apacket** ppacket)
+{
+    char *p = (char*) ppacket;  /* we really write the packet address */
+    int r, len = sizeof(ppacket);
+    char buff[8];
+    if (!name) {
+        snprintf(buff, sizeof buff, "fd=%d", fd);
+        name = buff;
+    }
+
+#if ADB_TRACE
+    if (ADB_TRACING) {
+        dump_packet(name, "to remote", *ppacket);
+    }
+#endif
+    len = sizeof(ppacket);
+    while(len > 0) {
+        r = adb_write(fd, p, len);
+        if(r > 0) {
+            len -= r;
+            p += r;
+        } else {
+            D("%s: write_packet (fd=%d) error ret=%d errno=%d: %s\n", name, fd, r, errno, strerror(errno));
+            if((r < 0) && (errno == EINTR)) continue;
+            return -1;
+        }
+    }
+    return 0;
+}
+
+static void transport_socket_events(int fd, unsigned events, void *_t)
+{
+    atransport *t = _t;
+    D("transport_socket_events(fd=%d, events=%04x,...)\n", fd, events);
+    if(events & FDE_READ){
+        apacket *p = 0;
+        if(read_packet(fd, t->serial, &p)){
+            D("%s: failed to read packet from transport socket on fd %d\n", t->serial, fd);
+        } else {
+            handle_packet(p, (atransport *) _t);
+        }
+    }
+}
+
+void send_packet(apacket *p, atransport *t)
+{
+    unsigned char *x;
+    unsigned sum;
+    unsigned count;
+
+    p->msg.magic = p->msg.command ^ 0xffffffff;
+
+    count = p->msg.data_length;
+    x = (unsigned char *) p->data;
+    sum = 0;
+    while(count-- > 0){
+        sum += *x++;
+    }
+    p->msg.data_check = sum;
+
+    print_packet("send", p);
+
+    if (t == NULL) {
+        D("Transport is null \n");
+        // Zap errno because print_packet() and other stuff have errno effect.
+        errno = 0;
+        fatal_errno("Transport is null");
+    }
+
+    if(write_packet(t->transport_socket, t->serial, &p)){
+        fatal_errno("cannot enqueue packet on transport socket");
+    }
+}
+
+/* The transport is opened by transport_register_func before
+** the input and output threads are started.
+**
+** The output thread issues a SYNC(1, token) message to let
+** the input thread know to start things up.  In the event
+** of transport IO failure, the output thread will post a
+** SYNC(0,0) message to ensure shutdown.
+**
+** The transport will not actually be closed until both
+** threads exit, but the input thread will kick the transport
+** on its way out to disconnect the underlying device.
+*/
+
+static void *output_thread(void *_t)
+{
+    atransport *t = _t;
+    apacket *p;
+
+    D("%s: starting transport output thread on fd %d, SYNC online (%d)\n",
+       t->serial, t->fd, t->sync_token + 1);
+    p = get_apacket();
+    p->msg.command = A_SYNC;
+    p->msg.arg0 = 1;
+    p->msg.arg1 = ++(t->sync_token);
+    p->msg.magic = A_SYNC ^ 0xffffffff;
+    if(write_packet(t->fd, t->serial, &p)) {
+        put_apacket(p);
+        D("%s: failed to write SYNC packet\n", t->serial);
+        goto oops;
+    }
+
+    D("%s: data pump started\n", t->serial);
+    for(;;) {
+        p = get_apacket();
+
+        if(t->read_from_remote(p, t) == 0){
+            D("%s: received remote packet, sending to transport\n",
+              t->serial);
+            if(write_packet(t->fd, t->serial, &p)){
+                put_apacket(p);
+                D("%s: failed to write apacket to transport\n", t->serial);
+                goto oops;
+            }
+        } else {
+            D("%s: remote read failed for transport\n", t->serial);
+            put_apacket(p);
+            break;
+        }
+    }
+
+    D("%s: SYNC offline for transport\n", t->serial);
+    p = get_apacket();
+    p->msg.command = A_SYNC;
+    p->msg.arg0 = 0;
+    p->msg.arg1 = 0;
+    p->msg.magic = A_SYNC ^ 0xffffffff;
+    if(write_packet(t->fd, t->serial, &p)) {
+        put_apacket(p);
+        D("%s: failed to write SYNC apacket to transport", t->serial);
+    }
+
+oops:
+    D("%s: transport output thread is exiting\n", t->serial);
+    kick_transport(t);
+    transport_unref(t);
+    return 0;
+}
+
+static void *input_thread(void *_t)
+{
+    atransport *t = _t;
+    apacket *p;
+    int active = 0;
+
+    D("%s: starting transport input thread, reading from fd %d\n",
+       t->serial, t->fd);
+
+    for(;;){
+        if(read_packet(t->fd, t->serial, &p)) {
+            D("%s: failed to read apacket from transport on fd %d\n",
+               t->serial, t->fd );
+            break;
+        }
+        if(p->msg.command == A_SYNC){
+            if(p->msg.arg0 == 0) {
+                D("%s: transport SYNC offline\n", t->serial);
+                put_apacket(p);
+                break;
+            } else {
+                if(p->msg.arg1 == t->sync_token) {
+                    D("%s: transport SYNC online\n", t->serial);
+                    active = 1;
+                } else {
+                    D("%s: transport ignoring SYNC %d != %d\n",
+                      t->serial, p->msg.arg1, t->sync_token);
+                }
+            }
+        } else {
+            if(active) {
+                D("%s: transport got packet, sending to remote\n", t->serial);
+                t->write_to_remote(p, t);
+            } else {
+                D("%s: transport ignoring packet while offline\n", t->serial);
+            }
+        }
+
+        put_apacket(p);
+    }
+
+    // this is necessary to avoid a race condition that occured when a transport closes
+    // while a client socket is still active.
+    close_all_sockets(t);
+
+    D("%s: transport input thread is exiting, fd %d\n", t->serial, t->fd);
+    kick_transport(t);
+    transport_unref(t);
+    return 0;
+}
+
+
+static int transport_registration_send = -1;
+static int transport_registration_recv = -1;
+static fdevent transport_registration_fde;
+
+
+#if ADB_HOST
+static int list_transports_msg(char*  buffer, size_t  bufferlen)
+{
+    char  head[5];
+    int   len;
+
+    len = list_transports(buffer+4, bufferlen-4);
+    snprintf(head, sizeof(head), "%04x", len);
+    memcpy(buffer, head, 4);
+    len += 4;
+    return len;
+}
+
+/* this adds support required by the 'track-devices' service.
+ * this is used to send the content of "list_transport" to any
+ * number of client connections that want it through a single
+ * live TCP connection
+ */
+typedef struct device_tracker  device_tracker;
+struct device_tracker {
+    asocket          socket;
+    int              update_needed;
+    device_tracker*  next;
+};
+
+/* linked list of all device trackers */
+static device_tracker*   device_tracker_list;
+
+static void
+device_tracker_remove( device_tracker*  tracker )
+{
+    device_tracker**  pnode = &device_tracker_list;
+    device_tracker*   node  = *pnode;
+
+    adb_mutex_lock( &transport_lock );
+    while (node) {
+        if (node == tracker) {
+            *pnode = node->next;
+            break;
+        }
+        pnode = &node->next;
+        node  = *pnode;
+    }
+    adb_mutex_unlock( &transport_lock );
+}
+
+static void
+device_tracker_close( asocket*  socket )
+{
+    device_tracker*  tracker = (device_tracker*) socket;
+    asocket*         peer    = socket->peer;
+
+    D( "device tracker %p removed\n", tracker);
+    if (peer) {
+        peer->peer = NULL;
+        peer->close(peer);
+    }
+    device_tracker_remove(tracker);
+    free(tracker);
+}
+
+static int
+device_tracker_enqueue( asocket*  socket, apacket*  p )
+{
+    /* you can't read from a device tracker, close immediately */
+    put_apacket(p);
+    device_tracker_close(socket);
+    return -1;
+}
+
+static int
+device_tracker_send( device_tracker*  tracker,
+                     const char*      buffer,
+                     int              len )
+{
+    apacket*  p = get_apacket();
+    asocket*  peer = tracker->socket.peer;
+
+    memcpy(p->data, buffer, len);
+    p->len = len;
+    return peer->enqueue( peer, p );
+}
+
+
+static void
+device_tracker_ready( asocket*  socket )
+{
+    device_tracker*  tracker = (device_tracker*) socket;
+
+    /* we want to send the device list when the tracker connects
+    * for the first time, even if no update occured */
+    if (tracker->update_needed > 0) {
+        char  buffer[1024];
+        int   len;
+
+        tracker->update_needed = 0;
+
+        len = list_transports_msg(buffer, sizeof(buffer));
+        device_tracker_send(tracker, buffer, len);
+    }
+}
+
+
+asocket*
+create_device_tracker(void)
+{
+    device_tracker*  tracker = calloc(1,sizeof(*tracker));
+
+    if(tracker == 0) fatal("cannot allocate device tracker");
+
+    D( "device tracker %p created\n", tracker);
+
+    tracker->socket.enqueue = device_tracker_enqueue;
+    tracker->socket.ready   = device_tracker_ready;
+    tracker->socket.close   = device_tracker_close;
+    tracker->update_needed  = 1;
+
+    tracker->next       = device_tracker_list;
+    device_tracker_list = tracker;
+
+    return &tracker->socket;
+}
+
+
+/* call this function each time the transport list has changed */
+void  update_transports(void)
+{
+    char             buffer[1024];
+    int              len;
+    device_tracker*  tracker;
+
+    len = list_transports_msg(buffer, sizeof(buffer));
+
+    tracker = device_tracker_list;
+    while (tracker != NULL) {
+        device_tracker*  next = tracker->next;
+        /* note: this may destroy the tracker if the connection is closed */
+        device_tracker_send(tracker, buffer, len);
+        tracker = next;
+    }
+}
+#else
+void  update_transports(void)
+{
+    // nothing to do on the device side
+}
+#endif // ADB_HOST
+
+typedef struct tmsg tmsg;
+struct tmsg
+{
+    atransport *transport;
+    int         action;
+};
+
+static int
+transport_read_action(int  fd, struct tmsg*  m)
+{
+    char *p   = (char*)m;
+    int   len = sizeof(*m);
+    int   r;
+
+    while(len > 0) {
+        r = adb_read(fd, p, len);
+        if(r > 0) {
+            len -= r;
+            p   += r;
+        } else {
+            if((r < 0) && (errno == EINTR)) continue;
+            D("transport_read_action: on fd %d, error %d: %s\n",
+              fd, errno, strerror(errno));
+            return -1;
+        }
+    }
+    return 0;
+}
+
+static int
+transport_write_action(int  fd, struct tmsg*  m)
+{
+    char *p   = (char*)m;
+    int   len = sizeof(*m);
+    int   r;
+
+    while(len > 0) {
+        r = adb_write(fd, p, len);
+        if(r > 0) {
+            len -= r;
+            p   += r;
+        } else {
+            if((r < 0) && (errno == EINTR)) continue;
+            D("transport_write_action: on fd %d, error %d: %s\n",
+              fd, errno, strerror(errno));
+            return -1;
+        }
+    }
+    return 0;
+}
+
+static void transport_registration_func(int _fd, unsigned ev, void *data)
+{
+    tmsg m;
+    adb_thread_t output_thread_ptr;
+    adb_thread_t input_thread_ptr;
+    int s[2];
+    atransport *t;
+
+    if(!(ev & FDE_READ)) {
+        return;
+    }
+
+    if(transport_read_action(_fd, &m)) {
+        fatal_errno("cannot read transport registration socket");
+    }
+
+    t = m.transport;
+
+    if(m.action == 0){
+        D("transport: %s removing and free'ing %d\n", t->serial, t->transport_socket);
+
+            /* IMPORTANT: the remove closes one half of the
+            ** socket pair.  The close closes the other half.
+            */
+        fdevent_remove(&(t->transport_fde));
+        adb_close(t->fd);
+
+        adb_mutex_lock(&transport_lock);
+        t->next->prev = t->prev;
+        t->prev->next = t->next;
+        adb_mutex_unlock(&transport_lock);
+
+        run_transport_disconnects(t);
+
+        if (t->product)
+            free(t->product);
+        if (t->serial)
+            free(t->serial);
+
+        memset(t,0xee,sizeof(atransport));
+        free(t);
+
+        update_transports();
+        return;
+    }
+
+    /* don't create transport threads for inaccessible devices */
+    if (t->connection_state != CS_NOPERM) {
+        /* initial references are the two threads */
+        t->ref_count = 2;
+
+        if(adb_socketpair(s)) {
+            fatal_errno("cannot open transport socketpair");
+        }
+
+        D("transport: %s (%d,%d) starting\n", t->serial, s[0], s[1]);
+
+        t->transport_socket = s[0];
+        t->fd = s[1];
+
+        fdevent_install(&(t->transport_fde),
+                        t->transport_socket,
+                        transport_socket_events,
+                        t);
+
+        fdevent_set(&(t->transport_fde), FDE_READ);
+
+        if(adb_thread_create(&input_thread_ptr, input_thread, t)){
+            fatal_errno("cannot create input thread");
+        }
+
+        if(adb_thread_create(&output_thread_ptr, output_thread, t)){
+            fatal_errno("cannot create output thread");
+        }
+    }
+
+        /* put us on the master device list */
+    adb_mutex_lock(&transport_lock);
+    t->next = &transport_list;
+    t->prev = transport_list.prev;
+    t->next->prev = t;
+    t->prev->next = t;
+    adb_mutex_unlock(&transport_lock);
+
+    t->disconnects.next = t->disconnects.prev = &t->disconnects;
+
+    update_transports();
+}
+
+void init_transport_registration(void)
+{
+    int s[2];
+
+    if(adb_socketpair(s)){
+        fatal_errno("cannot open transport registration socketpair");
+    }
+
+    transport_registration_send = s[0];
+    transport_registration_recv = s[1];
+
+    fdevent_install(&transport_registration_fde,
+                    transport_registration_recv,
+                    transport_registration_func,
+                    0);
+
+    fdevent_set(&transport_registration_fde, FDE_READ);
+}
+
+/* the fdevent select pump is single threaded */
+static void register_transport(atransport *transport)
+{
+    tmsg m;
+    m.transport = transport;
+    m.action = 1;
+    D("transport: %s registered\n", transport->serial);
+    if(transport_write_action(transport_registration_send, &m)) {
+        fatal_errno("cannot write transport registration socket\n");
+    }
+}
+
+static void remove_transport(atransport *transport)
+{
+    tmsg m;
+    m.transport = transport;
+    m.action = 0;
+    D("transport: %s removed\n", transport->serial);
+    if(transport_write_action(transport_registration_send, &m)) {
+        fatal_errno("cannot write transport registration socket\n");
+    }
+}
+
+
+static void transport_unref_locked(atransport *t)
+{
+    t->ref_count--;
+    if (t->ref_count == 0) {
+        D("transport: %s unref (kicking and closing)\n", t->serial);
+        if (!t->kicked) {
+            t->kicked = 1;
+            t->kick(t);
+        }
+        t->close(t);
+        remove_transport(t);
+    } else {
+        D("transport: %s unref (count=%d)\n", t->serial, t->ref_count);
+    }
+}
+
+static void transport_unref(atransport *t)
+{
+    if (t) {
+        adb_mutex_lock(&transport_lock);
+        transport_unref_locked(t);
+        adb_mutex_unlock(&transport_lock);
+    }
+}
+
+void add_transport_disconnect(atransport*  t, adisconnect*  dis)
+{
+    adb_mutex_lock(&transport_lock);
+    dis->next       = &t->disconnects;
+    dis->prev       = dis->next->prev;
+    dis->prev->next = dis;
+    dis->next->prev = dis;
+    adb_mutex_unlock(&transport_lock);
+}
+
+void remove_transport_disconnect(atransport*  t, adisconnect*  dis)
+{
+    dis->prev->next = dis->next;
+    dis->next->prev = dis->prev;
+    dis->next = dis->prev = dis;
+}
+
+
+atransport *acquire_one_transport(int state, transport_type ttype, const char* serial, char** error_out)
+{
+    atransport *t;
+    atransport *result = NULL;
+    int ambiguous = 0;
+
+retry:
+    if (error_out)
+        *error_out = "device not found";
+
+    adb_mutex_lock(&transport_lock);
+    for (t = transport_list.next; t != &transport_list; t = t->next) {
+        if (t->connection_state == CS_NOPERM) {
+        if (error_out)
+            *error_out = "insufficient permissions for device";
+            continue;
+        }
+
+        /* check for matching serial number */
+        if (serial) {
+            if (t->serial && !strcmp(serial, t->serial)) {
+                result = t;
+                break;
+            }
+        } else {
+            if (ttype == kTransportUsb && t->type == kTransportUsb) {
+                if (result) {
+                    if (error_out)
+                        *error_out = "more than one device";
+                    ambiguous = 1;
+                    result = NULL;
+                    break;
+                }
+                result = t;
+            } else if (ttype == kTransportLocal && t->type == kTransportLocal) {
+                if (result) {
+                    if (error_out)
+                        *error_out = "more than one emulator";
+                    ambiguous = 1;
+                    result = NULL;
+                    break;
+                }
+                result = t;
+            } else if (ttype == kTransportAny) {
+                if (result) {
+                    if (error_out)
+                        *error_out = "more than one device and emulator";
+                    ambiguous = 1;
+                    result = NULL;
+                    break;
+                }
+                result = t;
+            }
+        }
+    }
+    adb_mutex_unlock(&transport_lock);
+
+    if (result) {
+         /* offline devices are ignored -- they are either being born or dying */
+        if (result && result->connection_state == CS_OFFLINE) {
+            if (error_out)
+                *error_out = "device offline";
+            result = NULL;
+        }
+         /* check for required connection state */
+        if (result && state != CS_ANY && result->connection_state != state) {
+            if (error_out)
+                *error_out = "invalid device state";
+            result = NULL;
+        }
+    }
+
+    if (result) {
+        /* found one that we can take */
+        if (error_out)
+            *error_out = NULL;
+    } else if (state != CS_ANY && (serial || !ambiguous)) {
+        adb_sleep_ms(1000);
+        goto retry;
+    }
+
+    return result;
+}
+
+#if ADB_HOST
+static const char *statename(atransport *t)
+{
+    switch(t->connection_state){
+    case CS_OFFLINE: return "offline";
+    case CS_BOOTLOADER: return "bootloader";
+    case CS_DEVICE: return "device";
+    case CS_HOST: return "host";
+    case CS_RECOVERY: return "recovery";
+    case CS_SIDELOAD: return "sideload";
+    case CS_NOPERM: return "no permissions";
+    default: return "unknown";
+    }
+}
+
+int list_transports(char *buf, size_t  bufsize)
+{
+    char*       p   = buf;
+    char*       end = buf + bufsize;
+    int         len;
+    atransport *t;
+
+        /* XXX OVERRUN PROBLEMS XXX */
+    adb_mutex_lock(&transport_lock);
+    for(t = transport_list.next; t != &transport_list; t = t->next) {
+        const char* serial = t->serial;
+        if (!serial || !serial[0])
+            serial = "????????????";
+        len = snprintf(p, end - p, "%s\t%s\n", serial, statename(t));
+
+        if (p + len >= end) {
+            /* discard last line if buffer is too short */
+            break;
+        }
+        p += len;
+    }
+    p[0] = 0;
+    adb_mutex_unlock(&transport_lock);
+    return p - buf;
+}
+
+
+/* hack for osx */
+void close_usb_devices()
+{
+    atransport *t;
+
+    adb_mutex_lock(&transport_lock);
+    for(t = transport_list.next; t != &transport_list; t = t->next) {
+        if ( !t->kicked ) {
+            t->kicked = 1;
+            t->kick(t);
+        }
+    }
+    adb_mutex_unlock(&transport_lock);
+}
+#endif // ADB_HOST
+
+void register_socket_transport(int s, const char *serial, int port, int local)
+{
+    atransport *t = calloc(1, sizeof(atransport));
+    char buff[32];
+
+    if (!serial) {
+        snprintf(buff, sizeof buff, "T-%p", t);
+        serial = buff;
+    }
+    D("transport: %s init'ing for socket %d, on port %d\n", serial, s, port);
+    if ( init_socket_transport(t, s, port, local) < 0 ) {
+        adb_close(s);
+        free(t);
+        return;
+    }
+    if(serial) {
+        t->serial = strdup(serial);
+    }
+    register_transport(t);
+}
+
+#if ADB_HOST
+atransport *find_transport(const char *serial)
+{
+    atransport *t;
+
+    adb_mutex_lock(&transport_lock);
+    for(t = transport_list.next; t != &transport_list; t = t->next) {
+        if (t->serial && !strcmp(serial, t->serial)) {
+            break;
+        }
+     }
+    adb_mutex_unlock(&transport_lock);
+
+    if (t != &transport_list)
+        return t;
+    else
+        return 0;
+}
+
+void unregister_transport(atransport *t)
+{
+    adb_mutex_lock(&transport_lock);
+    t->next->prev = t->prev;
+    t->prev->next = t->next;
+    adb_mutex_unlock(&transport_lock);
+
+    kick_transport(t);
+    transport_unref(t);
+}
+
+// unregisters all non-emulator TCP transports
+void unregister_all_tcp_transports()
+{
+    atransport *t, *next;
+    adb_mutex_lock(&transport_lock);
+    for (t = transport_list.next; t != &transport_list; t = next) {
+        next = t->next;
+        if (t->type == kTransportLocal && t->adb_port == 0) {
+            t->next->prev = t->prev;
+            t->prev->next = next;
+            // we cannot call kick_transport when holding transport_lock
+            if (!t->kicked)
+            {
+                t->kicked = 1;
+                t->kick(t);
+            }
+            transport_unref_locked(t);
+        }
+     }
+
+    adb_mutex_unlock(&transport_lock);
+}
+
+#endif
+
+void register_usb_transport(usb_handle *usb, const char *serial, unsigned writeable)
+{
+    atransport *t = calloc(1, sizeof(atransport));
+    D("transport: %p init'ing for usb_handle %p (sn='%s')\n", t, usb,
+      serial ? serial : "");
+    init_usb_transport(t, usb, (writeable ? CS_OFFLINE : CS_NOPERM));
+    if(serial) {
+        t->serial = strdup(serial);
+    }
+    register_transport(t);
+}
+
+/* this should only be used for transports with connection_state == CS_NOPERM */
+void unregister_usb_transport(usb_handle *usb)
+{
+    atransport *t;
+    adb_mutex_lock(&transport_lock);
+    for(t = transport_list.next; t != &transport_list; t = t->next) {
+        if (t->usb == usb && t->connection_state == CS_NOPERM) {
+            t->next->prev = t->prev;
+            t->prev->next = t->next;
+            break;
+        }
+     }
+    adb_mutex_unlock(&transport_lock);
+}
+
+#undef TRACE_TAG
+#define TRACE_TAG  TRACE_RWX
+
+int readx(int fd, void *ptr, size_t len)
+{
+    char *p = ptr;
+    int r;
+#if ADB_TRACE
+    int  len0 = len;
+#endif
+    D("readx: fd=%d wanted=%d\n", fd, (int)len);
+    while(len > 0) {
+        r = adb_read(fd, p, len);
+        if(r > 0) {
+            len -= r;
+            p += r;
+        } else {
+            if (r < 0) {
+                D("readx: fd=%d error %d: %s\n", fd, errno, strerror(errno));
+                if (errno == EINTR)
+                    continue;
+            } else {
+                D("readx: fd=%d disconnected\n", fd);
+            }
+            return -1;
+        }
+    }
+
+#if ADB_TRACE
+    D("readx: fd=%d wanted=%d got=%d\n", fd, len0, len0 - len);
+    dump_hex( ptr, len0 );
+#endif
+    return 0;
+}
+
+int writex(int fd, const void *ptr, size_t len)
+{
+    char *p = (char*) ptr;
+    int r;
+
+#if ADB_TRACE
+    D("writex: fd=%d len=%d: ", fd, (int)len);
+    dump_hex( ptr, len );
+#endif
+    while(len > 0) {
+        r = adb_write(fd, p, len);
+        if(r > 0) {
+            len -= r;
+            p += r;
+        } else {
+            if (r < 0) {
+                D("writex: fd=%d error %d: %s\n", fd, errno, strerror(errno));
+                if (errno == EINTR)
+                    continue;
+            } else {
+                D("writex: fd=%d disconnected\n", fd);
+            }
+            return -1;
+        }
+    }
+    return 0;
+}
+
+int check_header(apacket *p)
+{
+    if(p->msg.magic != (p->msg.command ^ 0xffffffff)) {
+        D("check_header(): invalid magic\n");
+        return -1;
+    }
+
+    if(p->msg.data_length > MAX_PAYLOAD) {
+        D("check_header(): %d > MAX_PAYLOAD\n", p->msg.data_length);
+        return -1;
+    }
+
+    return 0;
+}
+
+int check_data(apacket *p)
+{
+    unsigned count, sum;
+    unsigned char *x;
+
+    count = p->msg.data_length;
+    x = p->data;
+    sum = 0;
+    while(count-- > 0) {
+        sum += *x++;
+    }
+
+    if(sum != p->msg.data_check) {
+        return -1;
+    } else {
+        return 0;
+    }
+}