in netutils/thttpd/libhttpd.c [2443:2651]
int httpd_got_request(httpd_conn *hc)
{
char c;
for (; hc->checked_idx < hc->read_idx; ++hc->checked_idx)
{
c = hc->read_buf[hc->checked_idx];
switch (hc->checked_state)
{
case CHST_FIRSTWORD:
switch (c)
{
case ' ':
case '\t':
hc->checked_state = CHST_FIRSTWS;
break;
case '\012':
case '\015':
hc->checked_state = CHST_BOGUS;
return GR_BAD_REQUEST;
}
break;
case CHST_FIRSTWS:
switch (c)
{
case ' ':
case '\t':
break;
case '\012':
case '\015':
hc->checked_state = CHST_BOGUS;
return GR_BAD_REQUEST;
default:
hc->checked_state = CHST_SECONDWORD;
break;
}
break;
case CHST_SECONDWORD:
switch (c)
{
case ' ':
case '\t':
hc->checked_state = CHST_SECONDWS;
break;
case '\012':
case '\015':
/* The first line has only two words - an HTTP/0.9 request. */
return GR_GOT_REQUEST;
}
break;
case CHST_SECONDWS:
switch (c)
{
case ' ':
case '\t':
break;
case '\012':
case '\015':
hc->checked_state = CHST_BOGUS;
return GR_BAD_REQUEST;
default:
hc->checked_state = CHST_THIRDWORD;
break;
}
break;
case CHST_THIRDWORD:
switch (c)
{
case ' ':
case '\t':
hc->checked_state = CHST_THIRDWS;
break;
case '\012':
hc->checked_state = CHST_LF;
break;
case '\015':
hc->checked_state = CHST_CR;
break;
}
break;
case CHST_THIRDWS:
switch (c)
{
case ' ':
case '\t':
break;
case '\012':
hc->checked_state = CHST_LF;
break;
case '\015':
hc->checked_state = CHST_CR;
break;
default:
hc->checked_state = CHST_BOGUS;
return GR_BAD_REQUEST;
}
break;
case CHST_LINE:
switch (c)
{
case '\012':
hc->checked_state = CHST_LF;
break;
case '\015':
hc->checked_state = CHST_CR;
break;
}
break;
case CHST_LF:
switch (c)
{
case '\012':
/* Two newlines in a row - a blank line - end of request. */
return GR_GOT_REQUEST;
case '\015':
hc->checked_state = CHST_CR;
break;
default:
hc->checked_state = CHST_LINE;
break;
}
break;
case CHST_CR:
switch (c)
{
case '\012':
hc->checked_state = CHST_CRLF;
break;
case '\015':
/* Two returns in a row - end of request. */
return GR_GOT_REQUEST;
default:
hc->checked_state = CHST_LINE;
break;
}
break;
case CHST_CRLF:
switch (c)
{
case '\012':
/* Two newlines in a row - end of request. */
return GR_GOT_REQUEST;
case '\015':
hc->checked_state = CHST_CRLFCR;
break;
default:
hc->checked_state = CHST_LINE;
break;
}
break;
case CHST_CRLFCR:
switch (c)
{
case '\012':
case '\015':
/* Two CRLFs or two CRs in a row - end of request. */
return GR_GOT_REQUEST;
default:
hc->checked_state = CHST_LINE;
break;
}
break;
case CHST_BOGUS:
return GR_BAD_REQUEST;
}
}
return GR_NO_REQUEST;
}