int
xml_getc(xml_reader_t *xr)
{
int cc;
if (xr->in_buffer) {
cc = ni_buffer_getc(xr->in_buffer);
if (cc == '\n')
xr->lineCount++;
return cc;
}
while (1) {
if (xr->pos) {
cc = *xr->pos++;
if (cc == '\n')
xr->lineCount++;
if (cc != '\0')
return cc;
xr->pos = NULL;
}
if (xr->file == NULL) {
/* Parsing just a string, no file backing */
break;
}
if (fgets((char *)xr->buffer, XML_READER_BUFSZ, xr->file) == NULL)
break;
xr->pos = xr->buffer;
}
return EOF;
}
/*
* Decode a CIDR list option.
*/
static int
ni_dhcp_decode_csr(ni_buffer_t *bp, ni_route_array_t *routes)
{
while (ni_buffer_count(bp) && !bp->underflow) {
ni_sockaddr_t destination, gateway;
struct in_addr prefix = { 0 };
unsigned int prefix_len;
ni_route_t *rp;
prefix_len = ni_buffer_getc(bp);
if (prefix_len > 32) {
ni_error("invalid prefix len of %u in classless static route", prefix_len);
return -1;
}
if (prefix_len)
ni_buffer_get(bp, &prefix, (prefix_len + 7) / 8);
ni_sockaddr_set_ipv4(&destination, prefix, 0);
if (ni_dhcp_option_get_sockaddr(bp, &gateway) < 0)
return -1;
rp = ni_route_create(prefix_len, &destination, &gateway, 0, NULL);
ni_route_array_append(routes, rp);
}
if (bp->underflow)
return -1;
return 0;
}
static int
ni_dhcp_option_get_netbios_type(ni_buffer_t *bp, unsigned int *type)
{
unsigned int len = ni_buffer_count(bp);
if (len != 1)
return -1;
*type = (unsigned int)ni_buffer_getc(bp);
switch (*type) {
case 0x1: /* B-node */
case 0x2: /* P-node */
case 0x4: /* M-node */
case 0x8: /* H-node */
return 0;
default:
break;
}
*type = 0;
return -1;
}
static int
ni_dhcp_decode_sipservers(ni_buffer_t *bp, ni_string_array_t *list)
{
int encoding;
encoding = ni_buffer_getc(bp);
switch (encoding) {
case -1:
ni_debug_dhcp("%s: missing data", __FUNCTION__);
return -1;
case 0:
return ni_dhcp_decode_dnssearch(bp, list, "sip-server name");
case 1:
return ni_dhcp_decode_address_list(bp, list);
default:
ni_error("unknown sip encoding %d", encoding);
return -1;
}
return 0;
}
/*
* Parse a DHCP response.
* FIXME: RFC2131 states that the server is allowed to split a DHCP option into
* several (partial) options if the total length exceeds 255 octets. We don't
* handle this yet.
*/
int
ni_dhcp_parse_response(const ni_dhcp_message_t *message, ni_buffer_t *options, ni_addrconf_lease_t **leasep)
{
ni_buffer_t overload_buf;
ni_addrconf_lease_t *lease;
ni_route_array_t default_routes = NI_ROUTE_ARRAY_INIT;
ni_route_array_t static_routes = NI_ROUTE_ARRAY_INIT;
ni_route_array_t classless_routes = NI_ROUTE_ARRAY_INIT;
ni_string_array_t dns_servers = NI_STRING_ARRAY_INIT;
ni_string_array_t dns_search = NI_STRING_ARRAY_INIT;
ni_string_array_t nis_servers = NI_STRING_ARRAY_INIT;
char *nisdomain = NULL;
char *dnsdomain = NULL;
int opt_overload = 0;
int msg_type = -1;
int use_bootserver = 1;
int use_bootfile = 1;
lease = ni_addrconf_lease_new(NI_ADDRCONF_DHCP, AF_INET);
lease->state = NI_ADDRCONF_STATE_GRANTED;
lease->type = NI_ADDRCONF_DHCP;
lease->family = AF_INET;
lease->time_acquired = time(NULL);
lease->dhcp.address.s_addr = message->yiaddr;
lease->dhcp.serveraddress.s_addr = message->siaddr;
lease->dhcp.address.s_addr = message->yiaddr;
parse_more:
/* Loop as long as we still have data in the buffer. */
while (ni_buffer_count(options) && !options->underflow) {
ni_buffer_t buf;
int option;
option = ni_dhcp_option_next(options, &buf);
//ni_debug_dhcp("handle option %s (%d)", ni_dhcp_option_name(option), option);
if (option == DHCP_PAD)
continue;
if (option == DHCP_END)
break;
if (option < 0)
goto error;
if (ni_buffer_count(&buf) == 0) {
ni_error("option %d has zero length", option);
goto error;
}
switch (option) {
case DHCP_MESSAGETYPE:
msg_type = ni_buffer_getc(&buf);
if (msg_type < 0)
goto error;
continue;
case DHCP_ADDRESS:
ni_dhcp_option_get_ipv4(&buf, &lease->dhcp.address);
break;
case DHCP_NETMASK:
ni_dhcp_option_get_ipv4(&buf, &lease->dhcp.netmask);
break;
case DHCP_BROADCAST:
ni_dhcp_option_get_ipv4(&buf, &lease->dhcp.broadcast);
break;
case DHCP_SERVERIDENTIFIER:
ni_dhcp_option_get_ipv4(&buf, &lease->dhcp.serveraddress);
break;
case DHCP_LEASETIME:
ni_dhcp_option_get32(&buf, &lease->dhcp.lease_time);
break;
case DHCP_RENEWALTIME:
ni_dhcp_option_get32(&buf, &lease->dhcp.renewal_time);
break;
case DHCP_REBINDTIME:
ni_dhcp_option_get32(&buf, &lease->dhcp.rebind_time);
break;
case DHCP_MTU:
ni_dhcp_option_get16(&buf, &lease->dhcp.mtu);
/* Minimum legal mtu is 68 accoridng to
* RFC 2132. In practise it's 576 which is the
* minimum maximum message size. */
if (lease->dhcp.mtu < MTU_MIN) {
ni_debug_dhcp("MTU %u is too low, minimum is %d; ignoring",
lease->dhcp.mtu, MTU_MIN);
lease->dhcp.mtu = 0;
}
break;
case DHCP_HOSTNAME:
ni_dhcp_option_get_domain(&buf, &lease->hostname,
"hostname");
break;
case DHCP_DNSDOMAIN:
ni_dhcp_option_get_domain(&buf, &dnsdomain,
"dns-domain");
break;
case DHCP_MESSAGE:
ni_dhcp_option_get_printable(&buf, &lease->dhcp.message,
"dhcp-message");
break;
case DHCP_ROOTPATH:
ni_dhcp_option_get_pathname(&buf, &lease->dhcp.rootpath,
"root-path");
break;
case DHCP_NISDOMAIN:
ni_dhcp_option_get_domain(&buf, &nisdomain,
"nis-domain");
break;
case DHCP_NETBIOSNODETYPE:
ni_dhcp_option_get_netbios_type(&buf, &lease->netbios_type);
break;
case DHCP_NETBIOSSCOPE:
ni_dhcp_option_get_domain(&buf, &lease->netbios_scope,
"netbios-scope");
break;
case DHCP_DNSSERVER:
ni_dhcp_decode_address_list(&buf, &dns_servers);
break;
case DHCP_NTPSERVER:
ni_dhcp_decode_address_list(&buf, &lease->ntp_servers);
break;
case DHCP_NISSERVER:
ni_dhcp_decode_address_list(&buf, &nis_servers);
break;
case DHCP_LPRSERVER:
ni_dhcp_decode_address_list(&buf, &lease->lpr_servers);
break;
case DHCP_LOGSERVER:
ni_dhcp_decode_address_list(&buf, &lease->log_servers);
break;
case DHCP_NETBIOSNAMESERVER:
ni_dhcp_decode_address_list(&buf, &lease->netbios_name_servers);
break;
case DHCP_NETBIOSDDSERVER:
ni_dhcp_decode_address_list(&buf, &lease->netbios_dd_servers);
break;
case DHCP_DNSSEARCH:
ni_dhcp_decode_dnssearch(&buf, &dns_search, "dns-search domain");
break;
case DHCP_CSR:
case DHCP_MSCSR:
ni_route_array_destroy(&classless_routes);
if (ni_dhcp_decode_csr(&buf, &classless_routes) < 0)
goto error;
break;
case DHCP_SIPSERVER:
ni_dhcp_decode_sipservers(&buf, &lease->sip_servers);
break;
case DHCP_STATICROUTE:
ni_route_array_destroy(&static_routes);
if (ni_dhcp_decode_static_routes(&buf, &static_routes) < 0)
goto error;
break;
case DHCP_ROUTERS:
ni_route_array_destroy(&default_routes);
if (ni_dhcp_decode_routers(&buf, &default_routes) < 0)
goto error;
break;
case DHCP_OPTIONSOVERLOADED:
if (options != &overload_buf) {
opt_overload = ni_buffer_getc(&buf);
} else {
ni_debug_dhcp("DHCP: ignoring OVERLOAD option in overloaded data");
(void) ni_buffer_getc(&buf);
}
break;
case DHCP_FQDN:
/* We ignore replies about FQDN */
break;
default:
ni_debug_dhcp("ignoring unsupported DHCP code %u", option);
break;
}
if (buf.underflow) {
ni_debug_dhcp("unable to parse DHCP option %s: too short",
ni_dhcp_option_name(option));
goto error;
} else if (ni_buffer_count(&buf)) {
ni_debug_dhcp("excess data in DHCP option %s - %u bytes left",
ni_dhcp_option_name(option),
ni_buffer_count(&buf));
}
}
if (options->underflow) {
ni_debug_dhcp("unable to parse DHCP response: truncated packet");
goto error;
}
if (opt_overload) {
const void *more_data = NULL;
size_t size = 0;
if (opt_overload & DHCP_OVERLOAD_BOOTFILE) {
use_bootfile = 0;
more_data = message->bootfile;
size = sizeof(message->bootfile);
opt_overload &= ~DHCP_OVERLOAD_BOOTFILE;
} else
if (opt_overload & DHCP_OVERLOAD_SERVERNAME) {
use_bootserver = 0;
more_data = message->servername;
size = sizeof(message->servername);
opt_overload &= ~DHCP_OVERLOAD_SERVERNAME;
} else {
opt_overload = 0;
}
if (more_data) {
ni_buffer_init_reader(&overload_buf, (void *) more_data, size);
options = &overload_buf;
goto parse_more;
}
}
if (use_bootserver && message->servername[0]) {
char tmp[sizeof(message->servername)];
size_t len;
assert(sizeof(lease->dhcp.servername) == sizeof(message->servername));
memcpy(tmp, message->servername, sizeof(tmp));
tmp[sizeof(tmp)-1] = '\0';
len = ni_string_len(tmp);
if (ni_check_domain_name(tmp, len, 0)) {
memcpy(lease->dhcp.servername, tmp, sizeof(lease->dhcp.servername));
} else {
ni_debug_dhcp("Discarded suspect boot-server name: %s",
ni_print_suspect(tmp, len));
}
}
if (use_bootfile && message->bootfile[0]) {
char tmp[sizeof(message->bootfile)];
size_t len;
memcpy(tmp, message->bootfile, sizeof(tmp));
tmp[sizeof(tmp)-1] = '\0';
len = ni_string_len(tmp);
if (ni_check_pathname(tmp, len)) {
ni_string_dup(&lease->dhcp.bootfile, tmp);
} else {
ni_debug_dhcp("Discarded suspect boot-file name: %s",
ni_print_suspect(tmp, len));
}
}
/* Fill in any missing fields */
if (!lease->dhcp.netmask.s_addr) {
unsigned int pfxlen = guess_prefix_len(lease->dhcp.address);
lease->dhcp.netmask.s_addr = htonl(~(0xFFFFFFFF >> pfxlen));
}
/*
* Decode an RFC3397 DNS search order option.
*/
static int
ni_dhcp_decode_dnssearch(ni_buffer_t *optbuf, ni_string_array_t *list, const char *what)
{
ni_stringbuf_t namebuf = NI_STRINGBUF_INIT_DYNAMIC;
unsigned char *base = ni_buffer_head(optbuf);
unsigned int base_offset = optbuf->head;
size_t len;
ni_string_array_destroy(list);
while (ni_buffer_count(optbuf) && !optbuf->underflow) {
ni_buffer_t *bp = optbuf;
ni_buffer_t jumpbuf;
while (1) {
unsigned int pos = bp->head - base_offset;
unsigned int pointer;
char label[64];
int length;
if ((length = ni_buffer_getc(bp)) < 0)
goto failure; /* unexpected EOF */
if (length == 0)
break; /* end of this name */
switch (length & 0xC0) {
case 0:
/* Plain name component */
if (ni_buffer_get(bp, label, length) < 0)
goto failure;
label[length] = '\0';
if (!ni_stringbuf_empty(&namebuf))
ni_stringbuf_putc(&namebuf, '.');
ni_stringbuf_puts(&namebuf, label);
break;
case 0xC0:
/* Pointer */
pointer = (length & 0x3F) << 8;
if ((length = ni_buffer_getc(bp)) < 0)
goto failure;
pointer |= length;
if (pointer >= pos)
goto failure;
ni_buffer_init_reader(&jumpbuf, base, pos);
jumpbuf.head = pointer;
bp = &jumpbuf;
break;
default:
goto failure;
}
}
if (!ni_stringbuf_empty(&namebuf)) {
len = ni_string_len(namebuf.string);
if (ni_check_domain_name(namebuf.string, len, 0)) {
ni_string_array_append(list, namebuf.string);
} else {
ni_debug_dhcp("Discarded suspect %s: %s", what,
ni_print_suspect(namebuf.string, len));
}
}
ni_stringbuf_destroy(&namebuf);
}
return 0;
failure:
ni_stringbuf_destroy(&namebuf);
ni_string_array_destroy(list);
return -1;
}