/** we can write */
static int _sx_get_pending_write(sx_t s) {
sx_buf_t in, out;
int ret;
assert(s != NULL);
if (s->wbufpending != NULL) {
/* there's already a pending buffer ready to write */
return 0;
}
/* get the first buffer off the queue */
in = jqueue_pull(s->wbufq);
if(in == NULL) {
/* if there was a write event, and something is interested,
we still have to tell the plugins */
in = _sx_buffer_new(NULL, 0, NULL, NULL);
}
/* if there's more to write, we want to make sure we get it */
s->want_write = jqueue_size(s->wbufq);
/* make a copy for processing */
out = _sx_buffer_new(in->data, in->len, in->notify, in->notify_arg);
_sx_debug(ZONE, "encoding %d bytes for writing: %.*s", in->len, in->len, in->data);
/* run it by the plugins */
ret = _sx_chain_io_write(s, out);
if(ret <= 0) {
/* TODO/!!!: Are we leaking the 'out' buffer here? How about the 'in' buffer? */
if(ret == -1) {
/* temporary failure, push it back on the queue */
jqueue_push(s->wbufq, in, (s->wbufq->front != NULL) ? s->wbufq->front->priority : 0);
s->want_write = 1;
} else if(ret == -2) {
/* permanent failure, its all over */
/* !!! shut down */
s->want_read = s->want_write = 0;
return -1;
}
/* done */
return 0;
}
_sx_buffer_free(in);
if (out->len == 0)
/* if there's nothing to write, then we're done */
_sx_buffer_free(out);
else
s->wbufpending = out;
return 0;
}
/** process handshake packets from the client */
static int _sx_ack_process(sx_t s, sx_plugin_t p, nad_t nad) {
int attr;
/* not interested if we're not a server */
if(s->type != type_SERVER)
return 1;
/* only want ack packets */
if((NAD_ENS(nad, 0) < 0 || NAD_NURI_L(nad, NAD_ENS(nad, 0)) != strlen(uri_ACK) || strncmp(NAD_NURI(nad, NAD_ENS(nad, 0)), uri_ACK, strlen(uri_ACK)) != 0))
return 1;
/* pings */
if(NAD_ENAME_L(nad, 0) == 4 && strncmp(NAD_ENAME(nad, 0), "ping", 4) == 0) {
jqueue_push(s->wbufq, _sx_buffer_new("<ack:pong/>", 11, NULL, NULL), 0);
s->want_write = 1;
/* handled the packet */
nad_free(nad);
return 0;
}
/* enable only when authenticated */
if(s->state == state_OPEN && NAD_ENAME_L(nad, 0) == 6 && strncmp(NAD_ENAME(nad, 0), "enable", 6) == 0) {
jqueue_push(s->wbufq, _sx_buffer_new("<ack:enabled/>", 14, NULL, NULL), 254);
s->want_write = 1;
s->plugin_data[p->index] = (void *) 1;
/* handled the packet */
nad_free(nad);
return 0;
}
/* 'r' or 'a' when enabled */
if(s->plugin_data[p->index] != NULL && NAD_ENAME_L(nad, 0) == 1 && (strncmp(NAD_ENAME(nad, 0), "r", 1) == 0 || strncmp(NAD_ENAME(nad, 0), "a", 1) == 0) ) {
attr = nad_find_attr(nad, 0, -1, "c", NULL);
if(attr >= 0) {
char *buf = (char *) malloc(sizeof(char) * (NAD_AVAL_L(nad, attr) + 13 + 1));
snprintf(buf, NAD_AVAL_L(nad, attr) + 13 + 1, "<ack:a b='%.*s'/>", NAD_AVAL_L(nad, attr), NAD_AVAL(nad, attr));
jqueue_push(s->wbufq, _sx_buffer_new(buf, NAD_AVAL_L(nad, attr) + 13, NULL, NULL), 255);
free(buf);
s->want_write = 1;
}
/* handled the packet */
nad_free(nad);
return 0;
}
_sx_debug(ZONE, "unhandled ack namespace element '%.*s', dropping packet", NAD_ENAME_L(nad, 0), NAD_ENAME(nad, 0));
nad_free(nad);
return 0;
}
/** close a stream */
void _sx_close(sx_t s) {
/* close the stream if necessary */
if(s->state >= state_STREAM_SENT) {
if (s->flags & SX_WEBSOCKET_WRAPPER)
jqueue_push(s->wbufq, _sx_buffer_new("<close xmlns='" uri_XFRAMING "' />", sizeof(uri_XFRAMING) + 17, NULL, NULL), 0);
else
jqueue_push(s->wbufq, _sx_buffer_new("</stream:stream>", 16, NULL, NULL), 0);
s->want_write = 1;
}
_sx_state(s, state_CLOSING);
}
//** send an extended error with custom contents other than text */
// Ideally should be merged with sx_error. sx_error should permit additional content beneath the <stream:error> element, other than a <text> node.
void _sx_error_extended(sx_t s, int err, const char *content) {
int len = 0;
sx_buf_t buf;
/* build the string */
if(s->state < state_STREAM) len = strlen(uri_STREAMS) + 61;
len += strlen(uri_STREAMS) + strlen(uri_STREAM_ERR) + strlen(_stream_errors[err]) + 58;
if(content != NULL) len += strlen(content) + strlen(_stream_errors[err]) + 2;
buf = _sx_buffer_new(NULL, len, NULL, NULL);
len = 0;
if(s->state < state_STREAM)
len = sprintf(buf->data, "<stream:stream xmlns:stream='" uri_STREAMS "' version='1.0'>");
if(content == NULL)
len += sprintf(&(buf->data[len]), "<stream:error xmlns:stream='" uri_STREAMS "'><%s xmlns='" uri_STREAM_ERR "'/></stream:error>", _stream_errors[err]);
else
len += sprintf(&(buf->data[len]), "<stream:error xmlns:stream='" uri_STREAMS "'><%s xmlns='" uri_STREAM_ERR "'>%s</%s></stream:error>", _stream_errors[err], content, _stream_errors[err]);
if(s->state < state_STREAM)
len += sprintf(&(buf->data[len]), "</stream:stream>");
buf->len--;
assert(len == buf->len);
_sx_debug(ZONE, "prepared error: %.*s", buf->len, buf->data);
/* go */
jqueue_push(s->wbufq, buf, 0);
/* stuff to write */
s->want_write = 1;
}
/** send a new nad out */
int _sx_nad_write(sx_t s, nad_t nad, int elem) {
const char *out;
int len;
/* silently drop it if we're closing or closed */
if(s->state >= state_CLOSING) {
log_debug(ZONE, "stream closed, dropping outgoing packet");
nad_free(nad);
return 1;
}
/* run it through the plugins */
if(_sx_chain_nad_write(s, nad, elem) == 0)
return 1;
/* serialise it */
nad_print(nad, elem, &out, &len);
_sx_debug(ZONE, "queueing for write: %.*s", len, out);
/* ready to go */
jqueue_push(s->wbufq, _sx_buffer_new(out, len, NULL, NULL), 0);
nad_free(nad);
/* things to write */
s->want_write = 1;
return 0;
}
int sx_compress_client_compress(sx_plugin_t p, sx_t s, const char *pemfile) {
assert((int) (p != NULL));
assert((int) (s != NULL));
/* sanity */
if(s->type != type_CLIENT || s->state != state_STREAM) {
_sx_debug(ZONE, "wrong conn type or state for client compress");
return 1;
}
/* check if we're already compressed */
if((s->flags & SX_COMPRESS_WRAPPER) || s->compressed) {
_sx_debug(ZONE, "channel already compressed");
return 1;
}
_sx_debug(ZONE, "initiating compress sequence");
/* go */
jqueue_push(s->wbufq, _sx_buffer_new("<compress xmlns='" uri_COMPRESS "'><method>zlib</method></compress>", sizeof(uri_COMPRESS)-1 + 51, NULL, NULL), 0);
s->want_write = 1;
_sx_event(s, event_WANT_WRITE, NULL);
return 0;
}
/** send an error */
void _sx_error(sx_t s, int err, const char *text) {
int len = 0;
sx_buf_t buf;
/* open stream if not already */
if(s->state < state_STREAM) {
if (s->flags & SX_WEBSOCKET_WRAPPER)
jqueue_push(s->wbufq, _sx_buffer_new("<open xmlns='" uri_XFRAMING "' version='1.0' />", sizeof(uri_XFRAMING) + 30, NULL, NULL), 0);
else
jqueue_push(s->wbufq, _sx_buffer_new("<stream:stream xmlns:stream='" uri_STREAMS "' version='1.0'>", sizeof(uri_STREAMS) + 44, NULL, NULL), 0);
}
/* build the error */
len = strlen(uri_STREAMS) + strlen(uri_STREAM_ERR) + strlen(_stream_errors[err]) + 58;
if(text != NULL) len += strlen(uri_STREAM_ERR) + strlen(text) + 22;
buf = _sx_buffer_new(NULL, len, NULL, NULL);
if(text == NULL)
len = sprintf(buf->data, "<stream:error xmlns:stream='" uri_STREAMS "'><%s xmlns='" uri_STREAM_ERR "'/></stream:error>", _stream_errors[err]);
else
len = sprintf(buf->data, "<stream:error xmlns:stream='" uri_STREAMS "'><%s xmlns='" uri_STREAM_ERR "'/><text xmlns='" uri_STREAM_ERR "'>%s</text></stream:error>", _stream_errors[err], text);
buf->len--;
assert(len == buf->len);
_sx_debug(ZONE, "prepared error: %.*s", buf->len, buf->data);
jqueue_push(s->wbufq, buf, 0);
/* close the stream if needed */
if(s->state < state_STREAM) {
if (s->flags & SX_WEBSOCKET_WRAPPER)
jqueue_push(s->wbufq, _sx_buffer_new("<close xmlns='" uri_XFRAMING "' />", sizeof(uri_XFRAMING) + 17, NULL, NULL), 0);
else
jqueue_push(s->wbufq, _sx_buffer_new("</stream:stream>", 16, NULL, NULL), 0);
}
/* stuff to write */
s->want_write = 1;
}
static void _sx_compress_new(sx_t s, sx_plugin_t p) {
_sx_compress_conn_t sc;
/* only bothering if they asked for wrappermode */
if(!(s->flags & SX_COMPRESS_WRAPPER) || s->compressed)
return;
_sx_debug(ZONE, "preparing for compressed connect for %d", s->tag);
sc = (_sx_compress_conn_t) calloc(1, sizeof(struct _sx_compress_conn_st));
/* initialize streams */
sc->rstrm.zalloc = Z_NULL;
sc->rstrm.zfree = Z_NULL;
sc->rstrm.opaque = Z_NULL;
sc->rstrm.avail_in = 0;
sc->rstrm.next_in = Z_NULL;
inflateInit(&(sc->rstrm));
sc->wstrm.zalloc = Z_NULL;
sc->wstrm.zfree = Z_NULL;
sc->wstrm.opaque = Z_NULL;
deflateInit(&(sc->wstrm), Z_DEFAULT_COMPRESSION);
/* read and write buffers */
sc->rbuf = _sx_buffer_new(NULL, 0, NULL, NULL);
sc->wbuf = _sx_buffer_new(NULL, 0, NULL, NULL);
s->plugin_data[p->index] = (void *) sc;
/* bring the plugin online */
_sx_chain_io_plugin(s, p);
/* mark stream compressed */
s->compressed = 1;
}
/** send raw data out */
int _sx_raw_write(sx_t s, const char *buf, int len) {
/* siltently drop it if we're closing or closed */
if(s->state >= state_CLOSING) {
log_debug(ZONE, "stream closed, dropping outgoing raw data");
return 1;
}
_sx_debug(ZONE, "queuing for write: %.*s", len, buf);
/* ready to go */
jqueue_push(s->wbufq, _sx_buffer_new(buf, len, NULL, NULL), 0);
/* things to write */
s->want_write = 1;
return 0;
}
/** handler for read data */
void _sx_process_read(sx_t s, sx_buf_t buf) {
sx_error_t sxe;
nad_t nad;
char *errstring;
int i;
int ns, elem;
/* Note that buf->len can validly be 0 here, if we got data from
the socket but the plugin didn't return anything to us (e.g. a
SSL packet was split across a tcp segment boundary) */
/* count bytes parsed */
s->pbytes += buf->len;
/* parse it */
if(XML_Parse(s->expat, buf->data, buf->len, 0) == 0) {
/* only report error we haven't already */
if(!s->fail) {
/* parse error */
errstring = (char *) XML_ErrorString(XML_GetErrorCode(s->expat));
_sx_debug(ZONE, "XML parse error: %s, character %d: %.*s",
errstring, XML_GetCurrentByteIndex(s->expat) - s->tbytes, buf->len, buf->data);
_sx_gen_error(sxe, SX_ERR_XML_PARSE, "XML parse error", errstring);
_sx_event(s, event_ERROR, (void *) &sxe);
_sx_error(s, stream_err_XML_NOT_WELL_FORMED, errstring);
_sx_close(s);
_sx_buffer_free(buf);
return;
}
/* !!! is this the right thing to do? we should probably set
* s->fail and let the code further down handle it. */
_sx_buffer_free(buf);
return;
}
/* check if the stanza size limit is exceeded (it wasn't reset by parser) */
if(s->rbytesmax && s->pbytes > s->rbytesmax) {
/* parse error */
_sx_debug(ZONE, "maximum stanza size (%d) exceeded by reading %d bytes", s->rbytesmax, s->pbytes);
errstring = (char *) XML_ErrorString(XML_GetErrorCode(s->expat));
_sx_gen_error(sxe, SX_ERR_XML_PARSE, "stream read error", "Maximum stanza size exceeded");
_sx_event(s, event_ERROR, (void *) &sxe);
_sx_error(s, stream_err_POLICY_VIOLATION, errstring);
_sx_close(s);
_sx_buffer_free(buf);
return;
}
/* count bytes processed */
s->tbytes += buf->len;
/* done with the buffer */
_sx_buffer_free(buf);
/* process completed nads */
if(s->state >= state_STREAM)
while((nad = jqueue_pull(s->rnadq)) != NULL) {
int plugin_error;
#ifdef SX_DEBUG
const char *out; int len;
nad_print(nad, 0, &out, &len);
_sx_debug(ZONE, "completed nad: %.*s", len, out);
#endif
/* check for errors */
if(NAD_ENS(nad, 0) >= 0 && NAD_NURI_L(nad, NAD_ENS(nad, 0)) == strlen(uri_STREAMS) && strncmp(NAD_NURI(nad, NAD_ENS(nad, 0)), uri_STREAMS, strlen(uri_STREAMS)) == 0 && NAD_ENAME_L(nad, 0) == 5 && strncmp(NAD_ENAME(nad, 0), "error", 5) == 0) {
errstring = NULL;
/* get text error description if available - XMPP 4.7.2 */
if((ns = nad_find_scoped_namespace(nad, uri_STREAM_ERR, NULL)) >= 0)
if((elem = nad_find_elem(nad, 0, ns, "text", 1)) >= 0)
if(NAD_CDATA_L(nad, elem) > 0) {
errstring = (char *) malloc(sizeof(char) * (NAD_CDATA_L(nad, elem) + 1));
sprintf(errstring, "%.*s", NAD_CDATA_L(nad, elem), NAD_CDATA(nad, elem));
}
/* if not available, look for legacy error text as in <stream:error>description</stream:error> */
if (errstring == NULL && NAD_CDATA_L(nad, 0) > 0) {
errstring = (char *) malloc(sizeof(char) * (NAD_CDATA_L(nad, 0) + 1));
sprintf(errstring, "%.*s", NAD_CDATA_L(nad, 0), NAD_CDATA(nad, 0));
}
/* if not available, log the whole packet for debugging */
if (errstring == NULL) {
const char *xml;
int xlen;
nad_print(nad, 0, &xml, &xlen);
errstring = (char *) malloc(sizeof(char) * (xlen + 1));
sprintf(errstring, "%.*s", xlen, xml);
}
if(s->state < state_CLOSING) {
_sx_gen_error(sxe, SX_ERR_STREAM, "Stream error", errstring);
_sx_event(s, event_ERROR, (void *) &sxe);
_sx_state(s, state_CLOSING);
}
free(errstring);
nad_free(nad);
break;
}
/* check for close */
if ((s->flags & SX_WEBSOCKET_WRAPPER) && NAD_ENS(nad, 0) >= 0 && NAD_NURI_L(nad, NAD_ENS(nad, 0)) == strlen(uri_XFRAMING) && strncmp(NAD_NURI(nad, NAD_ENS(nad, 0)), uri_XFRAMING, strlen(uri_XFRAMING)) == 0 && NAD_ENAME_L(nad, 0) == 5 && strncmp(NAD_ENAME(nad, 0), "close", 5) == 0) {
_sx_debug(ZONE, "<close/> frame @ depth %d", s->depth);
s->fail = 1;
break;
}
/* run it by the plugins */
if(_sx_chain_nad_read(s, nad) == 0)
return;
/* now let the plugins process the completed nad */
plugin_error = 0;
if(s->env != NULL)
for(i = 0; i < s->env->nplugins; i++)
if(s->env->plugins[i]->process != NULL) {
int plugin_ret;
plugin_ret = (s->env->plugins[i]->process)(s, s->env->plugins[i], nad);
if(plugin_ret == 0) {
plugin_error ++;
break;
}
}
/* hand it to the app */
if ((plugin_error == 0) && (s->state < state_CLOSING))
_sx_event(s, event_PACKET, (void *) nad);
}
/* something went wrong, bail */
if(s->fail) {
_sx_close(s);
return;
}
/* stream was closed */
if(s->depth < 0 && s->state < state_CLOSING) {
/* close the stream if necessary */
if(s->state >= state_STREAM_SENT) {
if (s->flags & SX_WEBSOCKET_WRAPPER)
jqueue_push(s->wbufq, _sx_buffer_new("<close xmlns='" uri_XFRAMING "' />", sizeof(uri_XFRAMING) + 17, NULL, NULL), 0);
else
jqueue_push(s->wbufq, _sx_buffer_new("</stream:stream>", 16, NULL, NULL), 0);
s->want_write = 1;
}
_sx_state(s, state_CLOSING);
return;
}
}
/** we can read */
int sx_can_read(sx_t s) {
sx_buf_t in, out;
int read, ret;
assert((int) (s != NULL));
/* do we care? */
if(!s->want_read && s->state < state_CLOSING)
return 0; /* no more thanks */
_sx_debug(ZONE, "%d ready for reading", s->tag);
/* new buffer */
in = _sx_buffer_new(NULL, 1024, NULL, NULL);
/* get them to read stuff */
read = _sx_event(s, event_READ, (void *) in);
/* bail if something went wrong */
if(read < 0) {
_sx_buffer_free(in);
s->want_read = 0;
s->want_write = 0;
return 0;
}
if(read == 0) {
/* nothing to read
* should never happen because we did get a read event,
* thus there is something to read, or error handled
* via (read < 0) block before (errors return -1) */
_sx_debug(ZONE, "decoded 0 bytes read data - this should not happen");
_sx_buffer_free(in);
} else {
_sx_debug(ZONE, "passed %d read bytes", in->len);
/* count bytes read */
s->rbytes += in->len;
/* make a copy for processing */
out = _sx_buffer_new(in->data, in->len, in->notify, in->notify_arg);
/* run it by the plugins */
ret = _sx_chain_io_read(s, out);
/* check if the stanza size limit is exceeded (it wasn't reset by parser) */
if(s->rbytesmax && s->rbytes > s->rbytesmax) {
_sx_debug(ZONE, "maximum stanza size (%d) exceeded by reading %d bytes", s->rbytesmax, s->pbytes);
/* make it fail */
ret = -1;
}
if(ret <= 0) {
if(ret < 0) {
/* permanent failure, its all over */
/* !!! shut down */
s->want_read = s->want_write = 0;
}
_sx_buffer_free(in);
_sx_buffer_free(out);
/* done */
if(s->want_write) _sx_event(s, event_WANT_WRITE, NULL);
return s->want_read;
}
_sx_buffer_free(in);
_sx_debug(ZONE, "decoded read data (%d bytes): %.*s", out->len, out->len, out->data);
/* into the parser with you */
_sx_process_read(s, out);
}
/* if we've written everything, and we're closed, then inform the app it can kill us */
if(s->want_write == 0 && s->state == state_CLOSING) {
_sx_state(s, state_CLOSED);
_sx_event(s, event_CLOSED, NULL);
return 0;
}
if(s->state == state_CLOSED)
return 0;
if(s->want_write) _sx_event(s, event_WANT_WRITE, NULL);
return s->want_read;
}
static int _sx_compress_process(sx_t s, sx_plugin_t p, nad_t nad) {
int flags;
char *ns = NULL, *to = NULL, *from = NULL, *version = NULL;
sx_error_t sxe;
/* not interested if we're a server and we never offered it */
if(s->type == type_SERVER && !(s->flags & SX_COMPRESS_OFFER))
return 1;
/* only want compress packets */
if(NAD_ENS(nad, 0) < 0 || NAD_NURI_L(nad, NAD_ENS(nad, 0)) != sizeof(uri_COMPRESS)-1 || strncmp(NAD_NURI(nad, NAD_ENS(nad, 0)), uri_COMPRESS, sizeof(uri_COMPRESS)-1) != 0)
return 1;
/* compress from client */
if(s->type == type_SERVER) {
if(NAD_ENAME_L(nad, 0) == 8 && strncmp(NAD_ENAME(nad, 0), "compress", 8) == 0) {
nad_free(nad);
/* can't go on if we've been here before */
if(s->compressed) {
_sx_debug(ZONE, "compress requested on already compressed channel, dropping packet");
return 0;
}
_sx_debug(ZONE, "compress requested, setting up");
/* go ahead */
jqueue_push(s->wbufq, _sx_buffer_new("<compressed xmlns='" uri_COMPRESS "'/>", sizeof(uri_COMPRESS)-1 + 22, _sx_compress_notify_compress, NULL), 0);
s->want_write = 1;
/* handled the packet */
return 0;
}
}
else if(s->type == type_CLIENT) {
/* kick off the handshake */
if(NAD_ENAME_L(nad, 0) == 7 && strncmp(NAD_ENAME(nad, 0), "compressed", 7) == 0) {
nad_free(nad);
/* save interesting bits */
flags = s->flags;
if(s->ns != NULL) ns = strdup(s->ns);
if(s->req_to != NULL) to = strdup(s->req_to);
if(s->req_from != NULL) from = strdup(s->req_from);
if(s->req_version != NULL) version = strdup(s->req_version);
/* reset state */
_sx_reset(s);
_sx_debug(ZONE, "server ready for compression, starting");
/* second time round */
sx_client_init(s, flags | SX_COMPRESS_WRAPPER, ns, to, from, version);
/* free bits */
if(ns != NULL) free(ns);
if(to != NULL) free(to);
if(from != NULL) free(from);
if(version != NULL) free(version);
return 0;
}
/* busted server */
if(NAD_ENAME_L(nad, 0) == 7 && strncmp(NAD_ENAME(nad, 0), "failure", 7) == 0) {
nad_free(nad);
_sx_debug(ZONE, "server can't handle compression, business as usual");
_sx_gen_error(sxe, SX_ERR_COMPRESS_FAILURE, "compress failure", "Server was unable to establish compression");
_sx_event(s, event_ERROR, (void *) &sxe);
return 0;
}
}
_sx_debug(ZONE, "unknown compress namespace element '%.*s', dropping packet", NAD_ENAME_L(nad, 0), NAD_ENAME(nad, 0));
nad_free(nad);
return 0;
}
