/** A callback routine that tests each DA discovered from DHCP.
*
* Each DA that passes is added to the DA cache.
*
* @param[in] tag - The DHCP option tag for this call.
* @param[in] optdata - A pointer to the DHCP option data for this call.
* @param[in] optdatasz - The size of @p optdata.
* @param[in] context - Callback context data. For this callback routine
* this parameter is actually a pointer to DHCPContext data.
*
* @return Zero on success, or a non-zero value to stop the caller from
* continuing to parse the buffer and call this routine.
*/
int DHCPParseSLPTags(int tag, void * optdata, size_t optdatasz,
void * context)
{
size_t cpysz, bufsz, dasize;
DHCPContext * ctxp = (DHCPContext *)context;
unsigned char * p = (unsigned char *)optdata;
unsigned char flags;
int encoding;
/* filter out zero length options */
if (!optdatasz)
return 0;
switch(tag)
{
case TAG_SLP_SCOPE:
/* Draft 3 format is only supported for ASCII and UNICODE
* character encodings - UTF8 encodings must use rfc2610 format.
* To determine the format, we parse 2 bytes and see if the result
* is a valid encoding. If so it's draft 3, otherwise rfc2610.
*/
encoding = (optdatasz > 1)? AS_UINT16(p): 0;
if (encoding != CT_ASCII && encoding != CT_UNICODE)
{
/* rfc2610 format */
if (optdatasz == 1)
break; /* UA's should ignore statically configured
* scopes for this interface -
* add code to handle this later...
*/
flags = *p++; /* pick up the mandatory flag... */
optdatasz--;
if (flags)
; /* ...and add code to handle it later... */
/* copy utf8 string into return buffer */
ctxp->scopelistlen = optdatasz < sizeof(ctxp->scopelist)?
optdatasz: sizeof(ctxp->scopelist);
strncpy(ctxp->scopelist, (char*)p, ctxp->scopelistlen);
ctxp->scopelist[sizeof(ctxp->scopelist) - 1] = 0;
}
else
{
/* Draft 3 format: defined to configure scopes for SA's only
* so we should flag the scopes to be used only as registration
* filter scopes - add code to handle this case later...
*
* offs len name description
* 0 2 encoding character encoding used
* 2 n scopelist list of scopes as asciiz string.
*
*/
optdatasz -= 2; /* skip encoding bytes */
p += 2;
/* if UNICODE encoding is used convert to utf8 */
if (encoding == CT_UNICODE)
wcstombs(ctxp->scopelist, (wchar_t*)p, sizeof(ctxp->scopelist));
else
{
ctxp->scopelistlen = optdatasz < sizeof(ctxp->scopelist)?
optdatasz: sizeof(ctxp->scopelist);
strncpy(ctxp->scopelist, (char*)p, ctxp->scopelistlen);
ctxp->scopelist[sizeof(ctxp->scopelist) - 1] = 0;
}
}
break;
case TAG_SLP_DA:
flags = *p++;
optdatasz--;
/* If the flags byte has the high bit set, we know we are
* using draft 3 format, otherwise rfc2610 format.
*/
if (!(flags & DA_NAME_PRESENT))
{
/* rfc2610 format */
if (flags)
{
/* If the mandatory byte is non-zero, indicate that
* multicast is not to be used to dynamically discover
* directory agents on this interface by setting the
* LACBF_STATIC_DA flag in the LACB for this interface.
*/
/* skip this for now - deal with it later... */
}
bufsz = sizeof(ctxp->addrlist) - ctxp->addrlistlen;
cpysz = optdatasz < bufsz? optdatasz: bufsz;
memcpy(ctxp->addrlist + ctxp->addrlistlen, p, cpysz);
ctxp->addrlistlen += cpysz;
}
else
{
/* pre-rfc2610 (draft 3) format:
* offs len name description
* 0 1 flags contains 4 flags (defined above)
* 1 1 dasize name or addr length
* 2 dasize daname da name or ip address (flags)
*/
dasize = *p++;
optdatasz--;
if (dasize > optdatasz)
dasize = optdatasz;
if (flags & DA_NAME_IS_DNS)
; /* DA name contains dns name - we have to resolve - later... */
else
{ /* DA name is one 4-byte ip address */
if (dasize < 4)
break; /* oops, bad option format */
dasize = 4;
bufsz = sizeof(ctxp->addrlist) - ctxp->addrlistlen;
cpysz = dasize < bufsz? dasize: bufsz;
memcpy(ctxp->addrlist + ctxp->addrlistlen, p, cpysz);
ctxp->addrlistlen += cpysz;
}
if (flags & DISABLE_DA_MCAST)
; /* this is the equivalent of the rfc2610 mandatory bit */
}
break;
}
return 0;
}
/** Read an inbound datagram.
*
* @param[in] socklist - The list of monitored sockets.
* @param[in] sock - The socket to be read.
*
* @internal
*/
static void IncomingDatagramRead(SLPList * socklist, SLPDSocket * sock)
{
int bytesread;
int byteswritten;
socklen_t peeraddrlen = sizeof(struct sockaddr_storage);
char addr_str[INET6_ADDRSTRLEN];
sockfd_t sendsock = SLP_INVALID_SOCKET;
(void)socklist;
bytesread = recvfrom(sock->fd, (char*)sock->recvbuf->start,
G_SlpdProperty.MTU, 0, (struct sockaddr *)&sock->peeraddr,
&peeraddrlen);
if (bytesread > 0)
{
sock->recvbuf->end = sock->recvbuf->start + bytesread;
if (!sock->sendbuf)
/* Some of the error handling code expects a sendbuf to be available
* to be emptied, so make sure there is at least a minimal buffer
*/
sock->sendbuf = SLPBufferAlloc(1);
switch (SLPDProcessMessage(&sock->peeraddr, &sock->localaddr,
sock->recvbuf, &sock->sendbuf, 0))
{
case SLP_ERROR_PARSE_ERROR:
case SLP_ERROR_VER_NOT_SUPPORTED:
case SLP_ERROR_MESSAGE_NOT_SUPPORTED:
break;
default:
#ifdef DARWIN
/* If the socket is a multicast socket, find the designated UDP output socket for sending */
if (sock->state == DATAGRAM_MULTICAST)
if ((sendsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) != SLP_INVALID_SOCKET)
SLPNetworkSetSndRcvBuf(sendsock);
#endif
if (sendsock == SLP_INVALID_SOCKET)
sendsock = sock->fd;
/* check to see if we should send anything, breaking up individual packets in the buffer
into different sendto calls (should only be an issue with the loopback DA response)*/
if (sock->sendbuf)
{
sock->sendbuf->curpos = sock->sendbuf->start;
while (sock->sendbuf->curpos < sock->sendbuf->end)
{
int packetbytes = AS_UINT24(sock->sendbuf->curpos + 2);
byteswritten = sendto(sendsock, (char*)sock->sendbuf->curpos,
packetbytes, 0, (struct sockaddr *)&sock->peeraddr,
SLPNetAddrLen(&sock->peeraddr));
if (byteswritten != packetbytes)
{
/* May be an overflow reply */
int flags = AS_UINT16(sock->sendbuf->curpos + 5);
if ((byteswritten == -1) &&
#ifdef _WIN32
(WSAGetLastError() == WSAEMSGSIZE) &&
#else
(errno == EMSGSIZE) &&
#endif
(flags & SLP_FLAG_OVERFLOW))
{
int byteswrittenmax = sendto(sendsock, (char*)sock->sendbuf->curpos,
G_SlpdProperty.MTU, 0, (struct sockaddr *)&sock->peeraddr,
SLPNetAddrLen(&sock->peeraddr));
if (byteswrittenmax == G_SlpdProperty.MTU)
byteswritten = packetbytes;
}
}
if (byteswritten != packetbytes)
SLPDLog("NETWORK_ERROR - %d replying %s\n", errno,
SLPNetSockAddrStorageToString(&(sock->peeraddr),
addr_str, sizeof(addr_str)));
sock->sendbuf->curpos += packetbytes;
}
/* Only close if we allocated a new socket */
if (sendsock != sock->fd)
closesocket(sendsock);
}
break;
}
}
}