/*--------------------------------------------------------------------------*/
int ParseAuthBlock(SLPBuffer buffer, SLPAuthBlock* authblock)
/* Returns - Zero on success, SLP_ERROR_INTERNAL_ERROR (out of memory) or */
/* SLP_ERROR_PARSE_ERROR. */
/*--------------------------------------------------------------------------*/
{
/* make sure that min size is met */
if(buffer->end - buffer->curpos < 10)
{
return SLP_ERROR_PARSE_ERROR;
}
authblock->bsd = AsUINT16(buffer->curpos);
authblock->length = AsUINT16(buffer->curpos + 2);
if(authblock->length > buffer->end - buffer->curpos)
{
return SLP_ERROR_PARSE_ERROR;
}
authblock->timestamp = AsUINT32(buffer->curpos + 4);
authblock->spistrlen = AsUINT16(buffer->curpos + 8);
authblock->spistr = buffer->curpos + 10;
if(authblock->spistrlen > buffer->end - buffer->curpos + 10)
{
return SLP_ERROR_PARSE_ERROR;
}
authblock->authstruct = buffer->curpos + authblock->spistrlen + 10;
buffer->curpos = buffer->curpos + authblock->length;
return 0;
}
/*-------------------------------------------------------------------------*/
int ParseDAAdvert(SLPBuffer buffer, SLPDAAdvert* daadvert)
/*-------------------------------------------------------------------------*/
{
int result;
int i;
/* make sure that min size is met */
if(buffer->end - buffer->curpos < 4)
{
return SLP_ERROR_PARSE_ERROR;
}
/* parse out the error code */
daadvert->errorcode = AsUINT16(buffer->curpos);
buffer->curpos = buffer->curpos + 2;
/* parse out the bootstamp */
daadvert->bootstamp = AsUINT32(buffer->curpos);
buffer->curpos = buffer->curpos + 4;
/* parse out the url */
daadvert->urllen = AsUINT16(buffer->curpos);
buffer->curpos = buffer->curpos + 2;
if(daadvert->urllen > buffer->end - buffer->curpos)
{
return SLP_ERROR_PARSE_ERROR;
}
daadvert->url = buffer->curpos;
buffer->curpos = buffer->curpos + daadvert->urllen;
/* parse the scope list */
daadvert->scopelistlen = AsUINT16(buffer->curpos);
buffer->curpos = buffer->curpos + 2;
if(daadvert->scopelistlen > buffer->end - buffer->curpos)
{
return SLP_ERROR_PARSE_ERROR;
}
daadvert->scopelist = buffer->curpos;
buffer->curpos = buffer->curpos + daadvert->scopelistlen;
/* parse the attr list */
daadvert->attrlistlen = AsUINT16(buffer->curpos);
buffer->curpos = buffer->curpos + 2;
if(daadvert->attrlistlen > buffer->end - buffer->curpos)
{
return SLP_ERROR_PARSE_ERROR;
}
daadvert->attrlist = buffer->curpos;
buffer->curpos = buffer->curpos + daadvert->attrlistlen;
/* parse the SPI list */
daadvert->spilistlen = AsUINT16(buffer->curpos);
buffer->curpos = buffer->curpos + 2;
if(daadvert->spilistlen > buffer->end - buffer->curpos)
{
return SLP_ERROR_PARSE_ERROR;
}
daadvert->spilist = buffer->curpos;
buffer->curpos = buffer->curpos + daadvert->spilistlen;
/* parse out auth block count */
daadvert->authcount = *(buffer->curpos);
buffer->curpos = buffer->curpos + 1;
/* parse out the auth block (if any) */
if(daadvert->authcount)
{
daadvert->autharray = (SLPAuthBlock*)malloc(sizeof(SLPAuthBlock) * daadvert->authcount);
if(daadvert->autharray == 0)
{
return SLP_ERROR_INTERNAL_ERROR;
}
memset(daadvert->autharray,0,sizeof(SLPAuthBlock) * daadvert->authcount);
for(i=0;i<daadvert->authcount;i++)
{
result = ParseAuthBlock(buffer,&(daadvert->autharray[i]));
if(result) return result;
}
}
return 0;
}
/*=========================================================================*/
int DHCPGetOptionInfo(unsigned char *dhcpOptCodes, int dhcpOptCodeCnt,
DHCPInfoCallBack *dhcpInfoCB, void *context)
/* Calls dhcpInfoCB once for each requested option in dhcpOptCodes.
Returns - zero on success, non-zero on failure
errno ENOTCONN error during read
ETIME read timed out
ENOMEM out of memory
EINVAL parse error
BOOTP/DHCP packet header format:
Offs Len Name Description
0 1 opcode Message opcode: 1 = BOOTREQUEST, 2 = BOOTREPLY
1 1 htype Hardware address type (eg., 1 = 10mb ethernet)
2 1 hlen Hardware address length (eg., 6 = 10mb ethernet)
3 1 hops Client sets to zero, optionally used by relay agents
4 4 xid Transaction ID, random number chosen by client
8 2 secs Client sets to seconds since start of boot process
10 2 flags Bit 0: broadcast response bit
12 4 ciaddr Client IP address - only filled if client is bound
16 4 yiaddr 'your' (Client) IP address
20 4 siaddr IP address of next server to use in bootstrap
24 4 giaddr Relay agent IP address, used in booting via RA
28 16 chaddr Client hardware address
44 64 sname Optional server host name, null-terminated string
108 128 file Boot file name, null-terminated string
236 var options Optional parameters field
The options field has the following format:
Offs Len Name Description
0 4 cookie 4-byte cookie field: 99.130.83.99 (0x63825363)
Followed by 1-byte option codes and 1-byte option lengths, except
for the two special fixed length options, pad (0) and end (255).
Options are defined in slp_dhcp.h as TAG_XXX values. The two we
really care about here are options TAG_SLP_DA and TAG_SLP_SCOPE,
78 and 79, respectively.
The format for TAG_SLP_DA (starting with the tag) is:
Offs Len Name Description
0 1 tag TAG_SLP_DA - directory agent ip addresses
1 1 length length of remaining data in the option
2 1 mand flag: the use of these DA's is mandatory
3 4 a(0) 4-byte ip address
...
3+n*4 4 a(n) 4-byte ip address
The format for TAG_SLP_SCOPE (starting with the tag) is:
Offs Len Name Description
0 1 tag TAG_SLP_SCOPE - directory scopes to use
1 1 length length of remaining data in the option
2 1 mand flag: the use of these scopes is mandatory
3 var scopes a null-terminated, comma-separated string of scopes
The "DHCP Message Type" option must be included in every DHCP message.
All tags except for TAG_PAD(0) and TAG_END(255) begin with a tag value
followed by a length of remaining data value.
=========================================================================*/
{
UINT32 xid;
time_t timer;
struct timeval tv;
int sockfd, retries;
struct sockaddr_in sendaddr;
unsigned char chaddr[MAX_MACADDR_SIZE];
unsigned char hlen, htype;
unsigned char sndbuf[512];
unsigned char rcvbuf[512];
struct hostent *hep;
unsigned char *p;
size_t rcvbufsz = 0;
char host[256];
/* Get our IP and MAC addresses */
if(gethostname(host, (int)sizeof(host))
|| !(hep = gethostbyname(host))
|| dhcpGetAddressInfo((unsigned char *)hep->h_addr,
chaddr, &hlen, &htype))
return -1;
/* get a reasonably random transaction id value */
xid = (UINT32)time(&timer);
/* BOOTP request header */
memset(sndbuf, 0, 236); /* clear bootp header */
p = sndbuf;
*p++ = BOOTREQUEST; /* opcode */
*p++ = htype;
*p++ = hlen;
p++; /* hops */
ToUINT32(p, xid);
p += 2 * sizeof(UINT32); /* xid, secs, flags */
memcpy(p, hep->h_addr, 4);
p += 4 * sizeof(UINT32); /* ciaddr, yiaddr, siaddr, giaddr */
memcpy(p, chaddr, hlen);
p += 16 + 64 + 128; /* chaddr, sname and file */
*p++ = DHCP_COOKIE1; /* options, cookies 1-4 */
*p++ = DHCP_COOKIE2;
*p++ = DHCP_COOKIE3;
*p++ = DHCP_COOKIE4;
/* DHCP Message Type option */
*p++ = TAG_DHCP_MSG_TYPE;
*p++ = 1; /* option length */
*p++ = DHCP_MSG_INFORM; /* message type is DHCPINFORM */
/* DHCP Parameter Request option */
*p++ = TAG_DHCP_PARAM_REQ; /* request for DHCP parms */
*p++ = (unsigned char)dhcpOptCodeCnt;
memcpy(p, dhcpOptCodes, dhcpOptCodeCnt);
p += dhcpOptCodeCnt;
/* DHCP Client Identifier option */
*p++ = TAG_CLIENT_IDENTIFIER;
*p++ = hlen + 1; /* option length */
*p++ = htype; /* client id is htype/haddr */
memcpy(p, chaddr, hlen);
p += hlen;
/* End option */
*p++ = TAG_END;
/* get a broadcast send/recv socket and address */
if((sockfd = dhcpCreateBCSkt(&sendaddr)) < 0)
return -1;
/* setup select timeout */
tv.tv_sec = 0;
tv.tv_usec = INIT_TMOUT_USECS;
retries = 0;
srand((unsigned)time(&timer));
while (retries++ < MAX_DHCP_RETRIES)
{
if(dhcpSendRequest(sockfd, sndbuf, p - sndbuf,
(struct sockaddr *)&sendaddr, &tv) < 0)
{
if (errno != ETIMEDOUT)
{
closesocket(sockfd);
return -1;
}
}
else if((rcvbufsz = dhcpRecvResponse(sockfd, rcvbuf,
sizeof(rcvbuf), &tv)) < 0)
{
if (errno != ETIMEDOUT)
{
closesocket(sockfd);
return -1;
}
}
else if(rcvbufsz >= 236 && AsUINT32(&rcvbuf[4]) == xid)
break;
/* exponential backoff randomized by a
uniform number between -1 and 1 */
tv.tv_usec = tv.tv_usec * 2 + (rand() % 3) - 1;
tv.tv_sec = tv.tv_usec / USECS_PER_SEC;
tv.tv_usec %= USECS_PER_SEC;
}
closesocket(sockfd);
return rcvbufsz? dhcpProcessOptions(rcvbuf + 236, rcvbufsz - 236,
dhcpInfoCB, context): -1;
}
