Revert "Implement SP wire protocol"

This reverts commit a34ea4d80609395150742259fd8c9caa4409e961.

35 files changed, 83 insertions, 597 deletions

diff --git a/include/xs/xs.h b/include/xs/xs.h
index 120bd1f..74d5f34 100644
--- a/include/xs/xs.h
+++ b/include/xs/xs.h
@@ -206,9 +206,8 @@ XS_EXPORT int xs_setctxopt (void *context, int option, const void *optval,
 #define XS_SNDTIMEO 28
 #define XS_IPV4ONLY 31
 #define XS_KEEPALIVE 32
-#define XS_PATTERN_VERSION 33
+#define XS_PROTOCOL 33
 #define XS_SURVEY_TIMEOUT 35
-#define XS_SERVICE_ID 36
 
 /*  Message options                                                           */
 #define XS_MORE 1
diff --git a/src/options.cpp b/src/options.cpp
index 26fa62c..62c03a2 100644
--- a/src/options.cpp
+++ b/src/options.cpp
@@ -48,12 +48,7 @@ xs::options_t::options_t () :
     sndtimeo (-1),
     ipv4only (1),
     keepalive (0),
-    legacy_protocol (false),
-    sp_service (0),
-    sp_pattern (-1),
-    sp_version (-1),
-    sp_role (-1),
-    sp_complement (-1),
+    protocol (0),
     filter (XS_FILTER_PREFIX),
     survey_timeout (-1),
     delay_on_close (true),
@@ -241,29 +236,29 @@ int xs::options_t::setsockopt (int option_, const void *optval_,
             return 0;
         }
 
-    case XS_FILTER:
-        if (optvallen_ != sizeof (int)) {
-            errno = EINVAL;
-            return -1;
-        }
-        filter = *((int*) optval_);
-        return 0;
-
-    case XS_SERVICE_ID:
+    case XS_PROTOCOL:
         {
             if (optvallen_ != sizeof (int)) {
                 errno = EINVAL;
                 return -1;
             }
             int val = *((int*) optval_);
-            if (val < 0 || val > 0xffff) {
+            if (val < 0) {
                 errno = EINVAL;
                 return -1;
             }
-            sp_service = val;
+            protocol = val;
             return 0;
         }
 
+    case XS_FILTER:
+        if (optvallen_ != sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        filter = *((int*) optval_);
+        return 0;
+
     case XS_SURVEY_TIMEOUT:
         if (type != XS_SURVEYOR) {
             errno = ENOTSUP;
@@ -457,21 +452,12 @@ int xs::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
         *optvallen_ = sizeof (int);
         return 0;
 
-    case XS_PATTERN_VERSION:
-        if (*optvallen_ < sizeof (int)) {
-            errno = EINVAL;
-            return -1;
-        }
-        *((int*) optval_) = sp_version;
-        *optvallen_ = sizeof (int);
-        return 0;
-
-    case XS_SERVICE_ID:
+    case XS_PROTOCOL:
         if (*optvallen_ < sizeof (int)) {
             errno = EINVAL;
             return -1;
         }
-        *((int*) optval_) = sp_service;
+        *((int*) optval_) = protocol;
         *optvallen_ = sizeof (int);
         return 0;
 
diff --git a/src/options.hpp b/src/options.hpp
index 9070c0f..805f793 100644
--- a/src/options.hpp
+++ b/src/options.hpp
@@ -92,16 +92,8 @@ namespace xs
         //  If 1, keepalives are to be sent periodically.
         int keepalive;
 
-        //  If true, the legacy non-SP wire protocol is in use.
-        bool legacy_protocol;
-
-        //  SP protocol service id, pattern, version, role and complementary
-        //  role.
-        int sp_service;
-        int sp_pattern;
-        int sp_version;
-        int sp_role;
-        int sp_complement;
+        //  Version of wire protocol to use.
+        int protocol;
 
         //  Filter ID to be used with subscriptions and unsubscriptions.
         int filter;
diff --git a/src/pair.cpp b/src/pair.cpp
index bfb48d3..531bfc5 100644
--- a/src/pair.cpp
+++ b/src/pair.cpp
@@ -23,17 +23,12 @@
 #include "err.hpp"
 #include "pipe.hpp"
 #include "msg.hpp"
-#include "wire.hpp"
 
 xs::pair_t::pair_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
     socket_base_t (parent_, tid_, sid_),
     pipe (NULL)
 {
     options.type = XS_PAIR;
-    options.sp_pattern = SP_PAIR;
-    options.sp_role = SP_PAIR_PAIR;
-    options.sp_version = 3;
-    options.sp_complement = SP_PAIR_PAIR;
 }
 
 xs::pair_t::~pair_t ()
@@ -41,34 +36,6 @@ xs::pair_t::~pair_t ()
     xs_assert (!pipe);
 }
 
-int xs::pair_t::xsetsockopt (int option_, const void *optval_,
-    size_t optvallen_)
-{
-    if (option_ != XS_PATTERN_VERSION) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    if (optvallen_ != sizeof (int)) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    if (!optval_) {
-        errno = EFAULT;
-        return -1;
-    }
-
-    int version = *(int *) optval_;
-    if (version != 2) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    options.sp_version = version;
-    return 0;
-}
-
 void xs::pair_t::xattach_pipe (pipe_t *pipe_, bool icanhasall_)
 {
     xs_assert (pipe_ != NULL);
diff --git a/src/pair.hpp b/src/pair.hpp
index 6a5f167..07ed6c5 100644
--- a/src/pair.hpp
+++ b/src/pair.hpp
@@ -42,7 +42,6 @@ namespace xs
         ~pair_t ();
 
         //  Overloads of functions from socket_base_t.
-        int xsetsockopt (int option_, const void *optval_, size_t optvallen_);
         void xattach_pipe (xs::pipe_t *pipe_, bool icanhasall_);
         int xsend (xs::msg_t *msg_, int flags_);
         int xrecv (xs::msg_t *msg_, int flags_);
diff --git a/src/pgm_receiver.cpp b/src/pgm_receiver.cpp
index 9aa1233..371c657 100644
--- a/src/pgm_receiver.cpp
+++ b/src/pgm_receiver.cpp
@@ -47,11 +47,6 @@ xs::pgm_receiver_t::pgm_receiver_t (class io_thread_t *parent_,
     pending_bytes (0),
     rx_timer (NULL)
 {
-    //  If not using a legacy protocol, fill in desired protocol header.
-    if (!options.legacy_protocol) {
-        sp_get_header (desired_header, options.sp_service, options.sp_pattern,
-            options.sp_version, options.sp_complement);
-    }
 }
 
 xs::pgm_receiver_t::~pgm_receiver_t ()
@@ -178,7 +173,7 @@ void xs::pgm_receiver_t::in_event (fd_t fd_)
         data = (unsigned char*) tmp;
 
         //  No data to process. This may happen if the packet received is
-        //  neither RDATA nor ODATA.
+        //  neither ODATA nor ODATA.
         if (received == 0) {
             if (errno == ENOMEM || errno == EBUSY) {
                 const long timeout = pgm_socket.get_rx_timeout ();
@@ -205,32 +200,18 @@ void xs::pgm_receiver_t::in_event (fd_t fd_)
             break;
         }
 
-        //  Check protocol header.
-        if (unlikely (!options.legacy_protocol)) {
-            if (received < (ssize_t) sizeof desired_header)
-                //  Ignore malformed datagram.
-                continue;
-            if (memcmp (data, desired_header, sizeof desired_header) != 0)
-                //  Ignore datagram with incorrect protocol header.
-                continue;
-            data += sizeof desired_header;
-            received -= sizeof desired_header;
+        //  New peer. Add it to the list of know but unjoint peers.
+        if (it == peers.end ()) {
+            peer_info_t peer_info = {false, NULL};
+            it = peers.insert (peers_t::value_type (*tsi, peer_info)).first;
         }
 
         //  Read the offset of the fist message in the current packet.
-        if (received < (ssize_t) sizeof (uint16_t))
-            //  Ignore malformed datagram.
-            continue;
+        xs_assert ((size_t) received >= sizeof (uint16_t));
         uint16_t offset = get_uint16 (data);
         data += sizeof (uint16_t);
         received -= sizeof (uint16_t);
 
-        //  New peer. Add it to the list of known but disjoint peers.
-        if (it == peers.end ()) {
-            peer_info_t peer_info = {false, NULL};
-            it = peers.insert (peers_t::value_type (*tsi, peer_info)).first;
-        }
-
         //  Join the stream if needed.
         if (!it->second.joined) {
 
diff --git a/src/pgm_receiver.hpp b/src/pgm_receiver.hpp
index c44594a..38c7a7b 100644
--- a/src/pgm_receiver.hpp
+++ b/src/pgm_receiver.hpp
@@ -39,7 +39,6 @@
 #include "options.hpp"
 #include "decoder.hpp"
 #include "pgm_socket.hpp"
-#include "wire.hpp"
 
 namespace xs
 {
@@ -126,9 +125,6 @@ namespace xs
         //  Receive timer, if active, otherwise NULL.
         handle_t rx_timer;
 
-        //  Desired protocol header.
-        sp_header_t desired_header;
-
         pgm_receiver_t (const pgm_receiver_t&);
         const pgm_receiver_t &operator = (const pgm_receiver_t&);
     };
diff --git a/src/pgm_sender.cpp b/src/pgm_sender.cpp
index d8d77b9..9c2a961 100644
--- a/src/pgm_sender.cpp
+++ b/src/pgm_sender.cpp
@@ -60,25 +60,6 @@ int xs::pgm_sender_t::init (bool udp_encapsulation_, const char *network_)
     out_buffer_size = pgm_socket.get_max_tsdu_size ();
     out_buffer = (unsigned char*) malloc (out_buffer_size);
     alloc_assert (out_buffer);
-    encode_buffer = out_buffer;
-    encode_buffer_size = out_buffer_size;
-    header_size = 0;
-
-    //  If not using a legacy protocol, fill in our datagram header and reserve
-    //  space for it in the datagram.
-    if (!options.legacy_protocol) {
-        sp_get_header (out_buffer, options.sp_service, options.sp_pattern,
-            options.sp_version, options.sp_role);
-        encode_buffer += SP_HEADER_LENGTH;
-        encode_buffer_size -= SP_HEADER_LENGTH;
-        header_size += SP_HEADER_LENGTH;
-    }
-
-    //  Reserve space in the datagram for the offset of the first message.
-    offset_p = encode_buffer;
-    encode_buffer += sizeof (uint16_t);
-    encode_buffer_size -= sizeof (uint16_t);
-    header_size += sizeof (uint16_t);
 
     return rc;
 }
@@ -175,25 +156,27 @@ void xs::pgm_sender_t::in_event (fd_t fd_)
 
 void xs::pgm_sender_t::out_event (fd_t fd_)
 {
-    //  POLLOUT event from send socket. If write buffer is empty (which means
-    //  that the last write succeeded), try to read new data from the encoder.
+    //  POLLOUT event from send socket. If write buffer is empty, 
+    //  try to read new data from the encoder.
     if (write_size == 0) {
 
-        //  Pass our own buffer to the get_data () function to prevent it from
-        //  returning its own buffer.
+        //  First two bytes (sizeof uint16_t) are used to store message 
+        //  offset in following steps. Note that by passing our buffer to
+        //  the get data function we prevent it from returning its own buffer.
+        unsigned char *bf = out_buffer + sizeof (uint16_t);
+        size_t bfsz = out_buffer_size - sizeof (uint16_t);
         int offset = -1;
-        size_t data_size = encode_buffer_size;
-        encoder.get_data (&encode_buffer, &data_size, &offset);
+        encoder.get_data (&bf, &bfsz, &offset);
 
         //  If there are no data to write stop polling for output.
-        if (!data_size) {
+        if (!bfsz) {
             reset_pollout (handle);
             return;
         }
 
         //  Put offset information in the buffer.
-        write_size = header_size + data_size;
-        put_uint16 (offset_p, offset == -1 ? 0xffff : (uint16_t) offset);
+        write_size = bfsz + sizeof (uint16_t);
+        put_uint16 (out_buffer, offset == -1 ? 0xffff : (uint16_t) offset);
     }
 
     if (tx_timer) {
diff --git a/src/pgm_sender.hpp b/src/pgm_sender.hpp
index 5a808b6..89f81bf 100644
--- a/src/pgm_sender.hpp
+++ b/src/pgm_sender.hpp
@@ -84,21 +84,12 @@ namespace xs
         handle_t rdata_notify_handle;
         handle_t pending_notify_handle;
 
-        //  Output buffer and size for pgm_socket.
+        //  Output buffer from pgm_socket.
         unsigned char *out_buffer;
+        
+        //  Output buffer size.
         size_t out_buffer_size;
 
-        //  Size of header in each datagram.
-        size_t header_size;
-
-        //  Encoder buffer and size, adjusted from output buffer by size of
-        //  datagram header(s).
-        unsigned char *encode_buffer;
-        size_t encode_buffer_size;
-
-        //  Position of offset to first message in output buffer.
-        unsigned char *offset_p;
-
         //  Number of bytes in the buffer to be written to the socket.
         //  If zero, there are no data to be sent.
         size_t write_size;
diff --git a/src/pipe.cpp b/src/pipe.cpp
index c14642f..0a15cc0 100644
--- a/src/pipe.cpp
+++ b/src/pipe.cpp
@@ -27,7 +27,7 @@
 #include "err.hpp"
 
 int xs::pipepair (class object_t *parents_ [2], class pipe_t* pipes_ [2],
-    int hwms_ [2], bool delays_ [2], int sp_version_)
+    int hwms_ [2], bool delays_ [2], int protocol_)
 {
     //   Creates two pipe objects. These objects are connected by two ypipes,
     //   each to pass messages in one direction.
@@ -38,10 +38,10 @@ int xs::pipepair (class object_t *parents_ [2], class pipe_t* pipes_ [2],
     alloc_assert (upipe2);
 
     pipes_ [0] = new (std::nothrow) pipe_t (parents_ [0], upipe1, upipe2,
-        hwms_ [1], hwms_ [0], delays_ [0], sp_version_);
+        hwms_ [1], hwms_ [0], delays_ [0], protocol_);
     alloc_assert (pipes_ [0]);
     pipes_ [1] = new (std::nothrow) pipe_t (parents_ [1], upipe2, upipe1,
-        hwms_ [0], hwms_ [1], delays_ [1], sp_version_);
+        hwms_ [0], hwms_ [1], delays_ [1], protocol_);
     alloc_assert (pipes_ [1]);
 
     pipes_ [0]->set_peer (pipes_ [1]);
@@ -51,7 +51,7 @@ int xs::pipepair (class object_t *parents_ [2], class pipe_t* pipes_ [2],
 }
 
 xs::pipe_t::pipe_t (object_t *parent_, upipe_t *inpipe_, upipe_t *outpipe_,
-      int inhwm_, int outhwm_, bool delay_, int sp_version_) :
+      int inhwm_, int outhwm_, bool delay_, int protocol_) :
     object_t (parent_),
     inpipe (inpipe_),
     outpipe (outpipe_),
@@ -66,7 +66,7 @@ xs::pipe_t::pipe_t (object_t *parent_, upipe_t *inpipe_, upipe_t *outpipe_,
     sink (NULL),
     state (active),
     delay (delay_),
-    sp_version (sp_version_)
+    protocol (protocol_)
 {
 }
 
@@ -386,9 +386,9 @@ void xs::pipe_t::terminate (bool delay_)
     }
 }
 
-int xs::pipe_t::get_sp_version ()
+int xs::pipe_t::get_protocol ()
 {
-    return sp_version;
+    return protocol;
 }
 
 bool xs::pipe_t::is_delimiter (msg_t &msg_)
diff --git a/src/pipe.hpp b/src/pipe.hpp
index dbc6b7e..c298154 100644
--- a/src/pipe.hpp
+++ b/src/pipe.hpp
@@ -44,7 +44,7 @@ namespace xs
     //  pipe receives all the pending messages before terminating, otherwise it
     //  terminates straight away.
     int pipepair (xs::object_t *parents_ [2], xs::pipe_t* pipes_ [2],
-        int hwms_ [2], bool delays_ [2], int sp_version_);
+        int hwms_ [2], bool delays_ [2], int protocol_);
 
     struct i_pipe_events
     {
@@ -69,7 +69,7 @@ namespace xs
         //  This allows pipepair to create pipe objects.
         friend int pipepair (xs::object_t *parents_ [2],
             xs::pipe_t* pipes_ [2], int hwms_ [2], bool delays_ [2],
-            int sp_version_);
+            int protocol_);
 
     public:
 
@@ -111,8 +111,8 @@ namespace xs
         //  before actual shutdown.
         void terminate (bool delay_);
 
-        //  Returns the SP pattern version in use on this pipe.
-        int get_sp_version ();
+        //  Returns the ID of the protocol associated with the pipe.
+        int get_protocol ();
 
     private:
 
@@ -132,7 +132,7 @@ namespace xs
         //  Constructor is private. Pipe can only be created using
         //  pipepair function.
         pipe_t (object_t *parent_, upipe_t *inpipe_, upipe_t *outpipe_,
-            int inhwm_, int outhwm_, bool delay_, int sp_version_);
+            int inhwm_, int outhwm_, bool delay_, int protocol_);
 
         //  Pipepair uses this function to let us know about
         //  the peer pipe object.
@@ -192,9 +192,9 @@ namespace xs
         //  asks us to.
         bool delay;
 
-        //  SP pattern version in use on this pipe. This value is used by the
-        //  pattern classes using the pipe, not the pipe itself.
-        int sp_version;
+        //  ID of the protocol to use. This value is not used by the pipe
+        //  itself, rather it's used by the users of the pipe.
+        int protocol;
 
         //  Identity of the writer. Used uniquely by the reader side.
         blob_t identity;
diff --git a/src/pull.cpp b/src/pull.cpp
index 0cedc39..8ae8208 100644
--- a/src/pull.cpp
+++ b/src/pull.cpp
@@ -23,50 +23,17 @@
 #include "err.hpp"
 #include "msg.hpp"
 #include "pipe.hpp"
-#include "wire.hpp"
 
 xs::pull_t::pull_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
     socket_base_t (parent_, tid_, sid_)
 {
     options.type = XS_PULL;
-    options.sp_pattern = SP_PIPELINE;
-    options.sp_version = 3;
-    options.sp_role = SP_PIPELINE_PULL;
-    options.sp_complement = SP_PIPELINE_PUSH;
 }
 
 xs::pull_t::~pull_t ()
 {
 }
 
-int xs::pull_t::xsetsockopt (int option_, const void *optval_,
-    size_t optvallen_)
-{
-    if (option_ != XS_PATTERN_VERSION) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    if (optvallen_ != sizeof (int)) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    if (!optval_) {
-        errno = EFAULT;
-        return -1;
-    }
-
-    int version = *(int *) optval_;
-    if (version != 2) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    options.sp_version = version;
-    return 0;
-}
-
 void xs::pull_t::xattach_pipe (pipe_t *pipe_, bool icanhasall_)
 {
     xs_assert (pipe_);
diff --git a/src/pull.hpp b/src/pull.hpp
index 5453bbd..04da465 100644
--- a/src/pull.hpp
+++ b/src/pull.hpp
@@ -45,7 +45,6 @@ namespace xs
     protected:
 
         //  Overloads of functions from socket_base_t.
-        int xsetsockopt (int option_, const void *optval_, size_t optvallen_);
         void xattach_pipe (xs::pipe_t *pipe_, bool icanhasall_);
         int xrecv (xs::msg_t *msg_, int flags_);
         bool xhas_in ();
diff --git a/src/push.cpp b/src/push.cpp
index 729c97a..59f508f 100644
--- a/src/push.cpp
+++ b/src/push.cpp
@@ -23,50 +23,17 @@
 #include "pipe.hpp"
 #include "err.hpp"
 #include "msg.hpp"
-#include "wire.hpp"
 
 xs::push_t::push_t (class ctx_t *parent_, uint32_t tid_, int sid_) :
     socket_base_t (parent_, tid_, sid_)
 {
     options.type = XS_PUSH;
-    options.sp_pattern = SP_PIPELINE;
-    options.sp_version = 3;
-    options.sp_role = SP_PIPELINE_PUSH;
-    options.sp_complement = SP_PIPELINE_PULL;
 }
 
 xs::push_t::~push_t ()
 {
 }
 
-int xs::push_t::xsetsockopt (int option_, const void *optval_,
-    size_t optvallen_)
-{
-    if (option_ != XS_PATTERN_VERSION) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    if (optvallen_ != sizeof (int)) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    if (!optval_) {
-        errno = EFAULT;
-        return -1;
-    }
-
-    int version = *(int *) optval_;
-    if (version != 2) {
-        errno = EINVAL;
-        return -1;
-    }
-
-    options.sp_version = version;
-    return 0;
-}
-
 void xs::push_t::xattach_pipe (pipe_t *pipe_, bool icanhasall_)
 {
     xs_assert (pipe_);
diff --git a/src/push.hpp b/src/push.hpp
index ffe16cc..a112f31 100644
--- a/src/push.hpp
+++ b/src/push.hpp
@@ -45,7 +45,6 @@ namespace xs
     protected:
 
         //  Overloads of functions from socket_base_t.
-        int xsetsockopt (int option_, const void *optval_, size_t optvallen_);
         void xattach_pipe (xs::pipe_t *pipe_, bool icanhasall_);
         int xsend (xs::msg_t *msg_, int flags_);
         bool xhas_out ();
diff --git a/src/session_base.cpp b/src/session_base.cpp
index 81f7347..49fdce1 100644
--- a/src/session_base.cpp
+++ b/src/session_base.cpp
@@ -300,7 +300,7 @@ void xs::session_base_t::process_attach (i_engine *engine_)
         pipe_t *pipes [2] = {NULL, NULL};
         int hwms [2] = {options.rcvhwm, options.sndhwm};
         bool delays [2] = {options.delay_on_close, options.delay_on_disconnect};
-        int rc = pipepair (parents, pipes, hwms, delays, options.sp_version);
+        int rc = pipepair (parents, pipes, hwms, delays, options.protocol);
         errno_assert (rc == 0);
 
         //  Plug the local end of the pipe.
diff --git a/src/socket_base.cpp b/src/socket_base.cpp
index b424a5e..9a8103e 100644
--- a/src/socket_base.cpp
+++ b/src/socket_base.cpp
@@ -451,7 +451,7 @@ int xs::socket_base_t::connect (const char *addr_)
         pipe_t *ppair [2] = {NULL, NULL};
         int hwms [2] = {sndhwm, rcvhwm};
         bool delays [2] = {options.delay_on_disconnect, options.delay_on_close};
-        rc = pipepair (parents, ppair, hwms, delays, options.sp_version);
+        rc = pipepair (parents, ppair, hwms, delays, options.protocol);
         errno_assert (rc == 0);
 
         //  Attach local end of the pipe to this socket object.
@@ -535,7 +535,7 @@ int xs::socket_base_t::connect (const char *addr_)
     pipe_t *ppair [2] = {NULL, NULL};
     int hwms [2] = {options.sndhwm, options.rcvhwm};
     bool delays [2] = {options.delay_on_disconnect, options.delay_on_close};
-    rc = pipepair (parents, ppair, hwms, delays, options.sp_version);
+    rc = pipepair (parents, ppair, hwms, delays, options.protocol);
     errno_assert (rc == 0);
 
     // PGM does not support subscription forwarding; ask for all data to be
diff --git a/src/stream_engine.cpp b/src/stream_engine.cpp
index b0f9f20..dc6d345 100644
--- a/src/stream_engine.cpp
+++ b/src/stream_engine.cpp
@@ -53,21 +53,8 @@ xs::stream_engine_t::stream_engine_t (fd_t fd_, const options_t &options_) :
     session (NULL),
     leftover_session (NULL),
     options (options_),
-    plugged (false),
-    header_pos (in_header),
-    header_remaining (sizeof in_header),
-    header_received (false),
-    header_sent (false)
+    plugged (false)
 {
-    //  Fill in outgoing SP protocol header and the complementary (desired)
-    //  header.
-    if (!options.legacy_protocol) {
-        sp_get_header (out_header, options.sp_service, options.sp_pattern,
-            options.sp_version, options.sp_role);
-        sp_get_header (desired_header, options.sp_service, options.sp_pattern,
-            options.sp_version, options.sp_complement);
-    }
-
     //  Get the socket into non-blocking mode.
     unblock_socket (s);
 
@@ -168,35 +155,6 @@ void xs::stream_engine_t::in_event (fd_t fd_)
 {
     bool disconnection = false;
 
-    //  If we have not yet received the full protocol header...
-    if (unlikely (!options.legacy_protocol && !header_received)) {
-
-        //  Read remaining header bytes.
-        int hbytes = read (header_pos, header_remaining);
-
-        //  Check whether the peer has closed the connection.
-        if (hbytes == -1) {
-            error ();
-            return;
-        }
-
-        header_remaining -= hbytes;
-        header_pos += hbytes;
-
-        //  If we did not read the whole header, poll for more.
-        if (header_remaining)
-            return;
-
-        //  If the protocol headers do not match, close the connection.
-        if (memcmp (in_header, desired_header, sizeof in_header) != 0) {
-            error ();
-            return;
-        }
-
-        //  Done with protocol header; proceed to read data.
-        header_received = true;
-    }
-
     //  If there's no data to process in the buffer...
     if (!insize) {
 
@@ -252,20 +210,6 @@ void xs::stream_engine_t::out_event (fd_t fd_)
 {
     bool more_data = true;
 
-    //  If protocol header was not yet sent...
-    if (unlikely (!options.legacy_protocol && !header_sent)) {
-        int hbytes = write (out_header, sizeof out_header);
-
-        //  It should always be possible to write the full protocol header to a
-        //  freshly connected TCP socket. Therefore, if we get an error or
-        //  partial write here the peer has disconnected.
-        if (hbytes != sizeof out_header) {
-            error ();
-            return;
-        }
-        header_sent = true;
-    }
-
     //  If write buffer is empty, try to read new data from the encoder.
     if (!outsize) {
 
diff --git a/src/stream_engine.hpp b/src/stream_engine.hpp
index 70c9ddb..46a6080 100644
--- a/src/stream_engine.hpp
+++ b/src/stream_engine.hpp
@@ -30,7 +30,6 @@
 #include "encoder.hpp"
 #include "decoder.hpp"
 #include "options.hpp"
-#include "wire.hpp"
 
 namespace xs
 {
@@ -99,22 +98,6 @@ namespace xs
 
         bool plugged;
 
-        //  Outgoing protocol header.
-        sp_header_t out_header;
-
-        //  Desired protocol header.
-        sp_header_t desired_header;
-
-        //  Incoming protocol header.
-        sp_header_t in_header;
-
-        unsigned char *header_pos;
-        size_t header_remaining;
-
-        //  Protocol header has been received/sent.
-        bool header_received;
-        bool header_sent;
-
         stream_engine_t (const stream_engine_t&);
         const stream_engine_t &operator = (const stream_engine_t&);
     };
diff --git a/src/sub.cpp b/src/sub.cpp
index 79cb63c..d29ae8d 100644
--- a/src/sub.cpp
+++ b/src/sub.cpp
@@ -48,7 +48,8 @@ int xs::sub_t::xsetsockopt (int option_, const void *optval_,
     size_t optvallen_)
 {
     if (option_ != XS_SUBSCRIBE && option_ != XS_UNSUBSCRIBE) {
-        return xsub_t::xsetsockopt (option_, optval_, optvallen_);
+        errno = EINVAL;
+        return -1;
     }
 
     if (optvallen_ > 0 && !optval_) {
@@ -201,7 +202,7 @@ int xs::sub_t::filter_subscribed (const unsigned char *data_, size_t size_)
     int rc = msg.init_size (size_ + 4);
     errno_assert (rc == 0);
     unsigned char *data = (unsigned char*) msg.data ();
-    put_uint16 (data, SP_PUBSUB_CMD_SUBSCRIBE);
+    put_uint16 (data, XS_CMD_SUBSCRIBE);
     put_uint16 (data + 2, options.filter);
     memcpy (data + 4, data_, size_);
 
@@ -224,7 +225,7 @@ int xs::sub_t::filter_unsubscribed (const unsigned char *data_, size_t size_)
     int rc = msg.init_size (size_ + 4);
     errno_assert (rc == 0);
     unsigned char *data = (unsigned char*) msg.data ();
-    put_uint16 (data, SP_PUBSUB_CMD_UNSUBSCRIBE);
+    put_uint16 (data, XS_CMD_UNSUBSCRIBE);
     put_uint16 (data + 2, options.filter);
     memcpy (data + 4, data_, size_);
 
diff --git a/src/wire.hpp b/src/wire.hpp
index 014021b..f840fce 100644
--- a/src/wire.hpp
+++ b/src/wire.hpp
@@ -24,52 +24,11 @@
 #i