diff --git a/adb/adb.cpp b/adb/adb.cpp
index 1727225..97ce125 100644
--- a/adb/adb.cpp
+++ b/adb/adb.cpp
@@ -334,10 +334,10 @@
     D("Calling send_connect \n");
     apacket *cp = get_apacket();
     cp->msg.command = A_CNXN;
-    cp->msg.arg0 = A_VERSION;
-    cp->msg.arg1 = MAX_PAYLOAD;
+    cp->msg.arg0 = t->get_protocol_version();
+    cp->msg.arg1 = t->get_max_payload();
     cp->msg.data_length = fill_connect_data((char *)cp->data,
-                                            sizeof(cp->data));
+                                            MAX_PAYLOAD_V1);
     send_packet(cp, t);
 }
 
@@ -424,12 +424,12 @@
         return;
 
     case A_CNXN: /* CONNECT(version, maxdata, "system-id-string") */
-            /* XXX verify version, etc */
         if(t->connection_state != kCsOffline) {
             t->connection_state = kCsOffline;
             handle_offline(t);
         }
 
+        t->update_version(p->msg.arg0, p->msg.arg1);
         parse_banner(reinterpret_cast<const char*>(p->data), t);
 
         if (HOST || !auth_required) {
diff --git a/adb/adb.h b/adb/adb.h
index 31fe3a5..357be51 100644
--- a/adb/adb.h
+++ b/adb/adb.h
@@ -25,7 +25,9 @@
 #include "adb_trace.h"
 #include "fdevent.h"
 
-#define MAX_PAYLOAD 4096
+constexpr size_t MAX_PAYLOAD_V1 = 4 * 1024;
+constexpr size_t MAX_PAYLOAD_V2 = 256 * 1024;
+constexpr size_t MAX_PAYLOAD = MAX_PAYLOAD_V2;
 
 #define A_SYNC 0x434e5953
 #define A_CNXN 0x4e584e43
@@ -137,6 +139,8 @@
 
         /* A socket is bound to atransport */
     atransport *transport;
+
+    size_t get_max_payload() const;
 };
 
 
@@ -193,6 +197,8 @@
     atransport() {
         auth_fde = {};
         transport_fde = {};
+        protocol_version = A_VERSION;
+        max_payload = MAX_PAYLOAD;
     }
 
     virtual ~atransport() {}
@@ -234,7 +240,14 @@
 
     const char* connection_state_name() const;
 
+    void update_version(int version, size_t payload);
+    int get_protocol_version() const;
+    size_t get_max_payload() const;
+
 private:
+    int protocol_version;
+    size_t max_payload;
+
     DISALLOW_COPY_AND_ASSIGN(atransport);
 };
 
diff --git a/adb/adb_auth.cpp b/adb/adb_auth.cpp
index cff26d6..8a6b156 100644
--- a/adb/adb_auth.cpp
+++ b/adb/adb_auth.cpp
@@ -75,7 +75,7 @@
     apacket *p = get_apacket();
     int ret;
 
-    ret = adb_auth_get_userkey(p->data, sizeof(p->data));
+    ret = adb_auth_get_userkey(p->data, MAX_PAYLOAD_V1);
     if (!ret) {
         D("Failed to get user public key\n");
         put_apacket(p);
diff --git a/adb/adb_auth_client.cpp b/adb/adb_auth_client.cpp
index 884d5be..be28202 100644
--- a/adb/adb_auth_client.cpp
+++ b/adb/adb_auth_client.cpp
@@ -54,7 +54,7 @@
 static void read_keys(const char *file, struct listnode *list)
 {
     FILE *f;
-    char buf[MAX_PAYLOAD];
+    char buf[MAX_PAYLOAD_V1];
     char *sep;
     int ret;
 
@@ -191,7 +191,7 @@
 
 void adb_auth_confirm_key(unsigned char *key, size_t len, atransport *t)
 {
-    char msg[MAX_PAYLOAD];
+    char msg[MAX_PAYLOAD_V1];
     int ret;
 
     if (!usb_transport) {
diff --git a/adb/adb_auth_host.cpp b/adb/adb_auth_host.cpp
index 8085c1a..b6bb00c 100644
--- a/adb/adb_auth_host.cpp
+++ b/adb/adb_auth_host.cpp
@@ -157,7 +157,7 @@
 {
     RSAPublicKey pkey;
     FILE *outfile = NULL;
-    char path[PATH_MAX], info[MAX_PAYLOAD];
+    char path[PATH_MAX], info[MAX_PAYLOAD_V1];
     uint8_t* encoded = nullptr;
     size_t encoded_length;
     int ret = 0;
diff --git a/adb/jdwp_service.cpp b/adb/jdwp_service.cpp
index 23af6c9..a2e0f88 100644
--- a/adb/jdwp_service.cpp
+++ b/adb/jdwp_service.cpp
@@ -608,7 +608,7 @@
     */
     if (jdwp->pass == 0) {
         apacket*  p = get_apacket();
-        p->len = jdwp_process_list((char*)p->data, MAX_PAYLOAD);
+        p->len = jdwp_process_list((char*)p->data, s->get_max_payload());
         peer->enqueue(peer, p);
         jdwp->pass = 1;
     }
@@ -695,7 +695,7 @@
     if (t->need_update) {
         apacket*  p = get_apacket();
         t->need_update = 0;
-        p->len = jdwp_process_list_msg((char*)p->data, sizeof(p->data));
+        p->len = jdwp_process_list_msg((char*)p->data, s->get_max_payload());
         s->peer->enqueue(s->peer, p);
     }
 }
diff --git a/adb/protocol.txt b/adb/protocol.txt
index 333e7e7..5c7c6ba 100644
--- a/adb/protocol.txt
+++ b/adb/protocol.txt
@@ -60,11 +60,14 @@
 declares the maximum message body size that the remote system
 is willing to accept.
 
-Currently, version=0x01000000 and maxdata=4096
+Currently, version=0x01000000 and maxdata=256*1024. Older versions of adb
+hard-coded maxdata=4096, so CONNECT and AUTH packets sent to a device must not
+be larger than that because they're sent before the CONNECT from the device
+that tells the adb server what maxdata the device can support.
 
 Both sides send a CONNECT message when the connection between them is
 established.  Until a CONNECT message is received no other messages may
-be sent.  Any messages received before a CONNECT message MUST be ignored.
+be sent. Any messages received before a CONNECT message MUST be ignored.
 
 If a CONNECT message is received with an unknown version or insufficiently
 large maxdata value, the connection with the other side must be closed.
diff --git a/adb/sockets.cpp b/adb/sockets.cpp
index 621944e..d8ea2ee 100644
--- a/adb/sockets.cpp
+++ b/adb/sockets.cpp
@@ -330,8 +330,9 @@
     if (ev & FDE_READ) {
         apacket *p = get_apacket();
         unsigned char *x = p->data;
-        size_t avail = MAX_PAYLOAD;
-        int r;
+        const size_t max_payload = s->get_max_payload();
+        size_t avail = max_payload;
+        int r = 0;
         int is_eof = 0;
 
         while (avail > 0) {
@@ -354,10 +355,10 @@
         }
         D("LS(%d): fd=%d post avail loop. r=%d is_eof=%d forced_eof=%d\n",
           s->id, s->fd, r, is_eof, s->fde.force_eof);
-        if ((avail == MAX_PAYLOAD) || (s->peer == 0)) {
+        if ((avail == max_payload) || (s->peer == 0)) {
             put_apacket(p);
         } else {
-            p->len = MAX_PAYLOAD - avail;
+            p->len = max_payload - avail;
 
             r = s->peer->enqueue(s->peer, p);
             D("LS(%d): fd=%d post peer->enqueue(). r=%d\n", s->id, s->fd,
@@ -569,9 +570,9 @@
 {
     D("Connect_to_remote call RS(%d) fd=%d\n", s->id, s->fd);
     apacket *p = get_apacket();
-    int len = strlen(destination) + 1;
+    size_t len = strlen(destination) + 1;
 
-    if(len > (MAX_PAYLOAD-1)) {
+    if(len > (s->get_max_payload()-1)) {
         fatal("destination oversized");
     }
 
@@ -700,7 +701,7 @@
         s->pkt_first = p;
         s->pkt_last = p;
     } else {
-        if((s->pkt_first->len + p->len) > MAX_PAYLOAD) {
+        if((s->pkt_first->len + p->len) > s->get_max_payload()) {
             D("SS(%d): overflow\n", s->id);
             put_apacket(p);
             goto fail;
@@ -901,3 +902,14 @@
     ss->peer = s;
     s->ready(s);
 }
+
+size_t asocket::get_max_payload() const {
+    size_t max_payload = MAX_PAYLOAD;
+    if (transport) {
+        max_payload = std::min(max_payload, transport->get_max_payload());
+    }
+    if (peer && peer->transport) {
+        max_payload = std::min(max_payload, peer->transport->get_max_payload());
+    }
+    return max_payload;
+}
diff --git a/adb/transport.cpp b/adb/transport.cpp
index 87ca5ac..87aff88 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -835,6 +835,19 @@
     }
 }
 
+void atransport::update_version(int version, size_t payload) {
+    protocol_version = std::min(version, A_VERSION);
+    max_payload = std::min(payload, MAX_PAYLOAD);
+}
+
+int atransport::get_protocol_version() const {
+    return protocol_version;
+}
+
+size_t atransport::get_max_payload() const {
+    return max_payload;
+}
+
 #if ADB_HOST
 
 static void append_transport_info(std::string* result, const char* key,
@@ -1020,15 +1033,16 @@
 #undef TRACE_TAG
 #define TRACE_TAG  TRACE_RWX
 
-int check_header(apacket *p)
+int check_header(apacket *p, atransport *t)
 {
     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);
+    if(p->msg.data_length > t->get_max_payload()) {
+        D("check_header(): %u > atransport::max_payload = %zu\n",
+            p->msg.data_length, t->get_max_payload());
         return -1;
     }
 
diff --git a/adb/transport.h b/adb/transport.h
index 538f63e..edcc99d 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -57,7 +57,7 @@
 void unregister_transport(atransport* t);
 void unregister_all_tcp_transports();
 
-int check_header(apacket* p);
+int check_header(apacket* p, atransport* t);
 int check_data(apacket* p);
 
 /* for MacOS X cleanup */
diff --git a/adb/transport_local.cpp b/adb/transport_local.cpp
index 97e3d50..1adc69e 100644
--- a/adb/transport_local.cpp
+++ b/adb/transport_local.cpp
@@ -53,7 +53,7 @@
         return -1;
     }
 
-    if(check_header(p)) {
+    if(check_header(p, t)) {
         D("bad header: terminated (data)\n");
         return -1;
     }
diff --git a/adb/transport_usb.cpp b/adb/transport_usb.cpp
index eb3454d..2c975a9 100644
--- a/adb/transport_usb.cpp
+++ b/adb/transport_usb.cpp
@@ -32,7 +32,7 @@
         return -1;
     }
 
-    if(check_header(p)) {
+    if(check_header(p, t)) {
         D("remote usb: check_header failed\n");
         return -1;
     }
diff --git a/adb/usb_linux.cpp b/adb/usb_linux.cpp
index c6f712b..439826a 100644
--- a/adb/usb_linux.cpp
+++ b/adb/usb_linux.cpp
@@ -439,36 +439,21 @@
 
 int usb_write(usb_handle *h, const void *_data, int len)
 {
-    unsigned char *data = (unsigned char*) _data;
-    int n;
-    int need_zero = 0;
-
     D("++ usb_write ++\n");
-    if(h->zero_mask) {
+
+    unsigned char *data = (unsigned char*) _data;
+    int n = usb_bulk_write(h, data, len);
+    if(n != len) {
+        D("ERROR: n = %d, errno = %d (%s)\n",
+            n, errno, strerror(errno));
+        return -1;
+    }
+
+    if(h->zero_mask && !(len & h->zero_mask)) {
             /* if we need 0-markers and our transfer
             ** is an even multiple of the packet size,
-            ** we make note of it
+            ** then send the zero markers.
             */
-        if(!(len & h->zero_mask)) {
-            need_zero = 1;
-        }
-    }
-
-    while(len > 0) {
-        int xfer = (len > 4096) ? 4096 : len;
-
-        n = usb_bulk_write(h, data, xfer);
-        if(n != xfer) {
-            D("ERROR: n = %d, errno = %d (%s)\n",
-                n, errno, strerror(errno));
-            return -1;
-        }
-
-        len -= xfer;
-        data += xfer;
-    }
-
-    if(need_zero){
         n = usb_bulk_write(h, _data, 0);
         return n;
     }
@@ -484,7 +469,7 @@
 
     D("++ usb_read ++\n");
     while(len > 0) {
-        int xfer = (len > 4096) ? 4096 : len;
+        int xfer = len;
 
         D("[ usb read %d fd = %d], fname=%s\n", xfer, h->desc, h->fname);
         n = usb_bulk_read(h, data, xfer);
diff --git a/adb/usb_linux_client.cpp b/adb/usb_linux_client.cpp
index cfd95dd..b1b3538 100644
--- a/adb/usb_linux_client.cpp
+++ b/adb/usb_linux_client.cpp
@@ -213,14 +213,20 @@
 
 static int usb_adb_read(usb_handle *h, void *data, int len)
 {
-    int n;
-
     D("about to read (fd=%d, len=%d)\n", h->fd, len);
-    n = unix_read(h->fd, data, len);
-    if(n != len) {
-        D("ERROR: fd = %d, n = %d, errno = %d (%s)\n",
-            h->fd, n, errno, strerror(errno));
-        return -1;
+    while (len > 0) {
+        // The kernel implementation of adb_read in f_adb.c doesn't support
+        // reads larger then 4096 bytes. Read the data in 4096 byte chunks to
+        // avoid the issue. (The ffs implementation doesn't have this limit.)
+        int bytes_to_read = len < 4096 ? len : 4096;
+        int n = unix_read(h->fd, data, bytes_to_read);
+        if (n != bytes_to_read) {
+            D("ERROR: fd = %d, n = %d, errno = %d (%s)\n",
+                h->fd, n, errno, strerror(errno));
+            return -1;
+        }
+        len -= n;
+        data = ((char*)data) + n;
     }
     D("[ done fd=%d ]\n", h->fd);
     return 0;