+
/*
* dhcp.c Functions to send/receive dhcp packets.
*
#include <freeradius-devel/libradius.h>
#include <freeradius-devel/udpfromto.h>
#include <freeradius-devel/dhcp.h>
+#include <freeradius-devel/net.h>
#ifndef __MINGW32__
#include <sys/ioctl.h>
#endif
/* @todo: this is a hack */
-# define DEBUG if (fr_debug_flag && fr_log_fp) fr_printf_log
-void fr_strerror_printf(char const *fmt, ...);
-# define debug_pair(vp) do { if (fr_debug_flag && fr_log_fp) { \
+# define DEBUG if (fr_debug_lvl && fr_log_fp) fr_printf_log
+# define debug_pair(vp) do { if (fr_debug_lvl && fr_log_fp) { \
vp_print(fr_log_fp, vp); \
} \
} while(0)
+#ifdef HAVE_LINUX_IF_PACKET_H
+#define ETH_HDR_SIZE 14
+#define IP_HDR_SIZE 20
+#define UDP_HDR_SIZE 8
+#define ETH_ADDR_LEN 6
+#define ETH_TYPE_IP 0x0800
+#define ETH_P_ALL 0x0003
+
+static uint8_t eth_bcast[ETH_ADDR_LEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+
+/* Discard raw packets which we are not interested in. Allow to trace why we discard. */
+#define DISCARD_RP(...) { \
+ if (fr_debug_lvl > 2) { \
+ fprintf(stdout, "dhcpclient: discarding received packet: "); \
+ fprintf(stdout, ## __VA_ARGS__); \
+ fprintf(stdout, "\n"); \
+ } \
+ rad_free(&packet); \
+ return NULL; \
+}
+#endif
+
typedef struct dhcp_packet_t {
uint8_t opcode;
uint8_t htype;
"DHCP-Release",
"DHCP-Inform",
"DHCP-Force-Renew",
+ "DHCP-Lease-Query",
+ "DHCP-Lease-Unassigned",
+ "DHCP-Lease-Unknown",
+ "DHCP-Lease-Active",
+ "DHCP-Bulk-Lease-Query",
+ "DHCP-Lease-Query-Done"
};
+#define DHCP_MAX_MESSAGE_TYPE (sizeof(dhcp_message_types) / sizeof(dhcp_message_types[0]))
+
static int dhcp_header_sizes[] = {
1, 1, 1, 1,
4, 2, 2, 4,
socklen_t sizeof_src;
socklen_t sizeof_dst;
RADIUS_PACKET *packet;
- int port;
+ uint16_t port;
uint8_t *code;
ssize_t data_len;
- packet = rad_alloc(NULL, 0);
+ packet = rad_alloc(NULL, false);
if (!packet) {
fr_strerror_printf("Failed allocating packet");
return NULL;
#endif
if (data_len <= 0) {
- fr_strerror_printf("Failed reading DHCP socket: %s", strerror(errno));
+ fr_strerror_printf("Failed reading DHCP socket: %s", fr_syserror(errno));
rad_free(&packet);
return NULL;
}
packet->data_len = data_len;
if (packet->data_len < MIN_PACKET_SIZE) {
fr_strerror_printf("DHCP packet is too small (%zu < %d)",
- packet->data_len, MIN_PACKET_SIZE);
+ packet->data_len, MIN_PACKET_SIZE);
rad_free(&packet);
return NULL;
}
if (packet->data_len > MAX_PACKET_SIZE) {
fr_strerror_printf("DHCP packet is too large (%zx > %d)",
- packet->data_len, MAX_PACKET_SIZE);
+ packet->data_len, MAX_PACKET_SIZE);
rad_free(&packet);
return NULL;
}
- if (packet->data[1] != 1) {
+ if (packet->data[1] > 1) {
fr_strerror_printf("DHCP can only receive ethernet requests, not type %02x",
packet->data[1]);
rad_free(&packet);
return NULL;
}
- if (packet->data[2] != 6) {
+ if ((packet->data[2] != 0) && (packet->data[2] != 6)) {
fr_strerror_printf("Ethernet HW length is wrong length %d",
packet->data[2]);
rad_free(&packet);
packet->id = ntohl(magic);
code = dhcp_get_option((dhcp_packet_t *) packet->data,
- packet->data_len, 53);
+ packet->data_len, PW_DHCP_MESSAGE_TYPE);
if (!code) {
fr_strerror_printf("No message-type option was found in the packet");
rad_free(&packet);
return NULL;
}
- if ((code[1] < 1) || (code[2] == 0) || (code[2] > 8)) {
- fr_strerror_printf("Unknown value for message-type option");
+ if ((code[1] < 1) || (code[2] == 0) || (code[2] >= DHCP_MAX_MESSAGE_TYPE)) {
+ fr_strerror_printf("Unknown value %d for message-type option", code[2]);
rad_free(&packet);
return NULL;
}
* This should never fail...
*/
if (getsockname(sockfd, (struct sockaddr *) &dst, &sizeof_dst) < 0) {
- fr_strerror_printf("getsockname failed: %s", strerror(errno));
+ fr_strerror_printf("getsockname failed: %s", fr_syserror(errno));
rad_free(&packet);
return NULL;
}
fr_sockaddr2ipaddr(&src, sizeof_src, &packet->src_ipaddr, &port);
packet->src_port = port;
- if (fr_debug_flag > 1) {
+ if (fr_debug_lvl > 1) {
char type_buf[64];
char const *name = type_buf;
char src_ip_buf[256], dst_ip_buf[256];
if ((packet->code >= PW_DHCP_DISCOVER) &&
- (packet->code <= PW_DHCP_INFORM)) {
+ (packet->code < (1024 + DHCP_MAX_MESSAGE_TYPE))) {
name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
} else {
snprintf(type_buf, sizeof(type_buf), "%d",
packet->code - PW_DHCP_OFFSET);
}
- DEBUG("Received %s of id %08x from %s:%d to %s:%d\n",
+ DEBUG("Received %s of Id %08x from %s:%d to %s:%d\n",
name, (unsigned int) packet->id,
inet_ntop(packet->src_ipaddr.af,
&packet->src_ipaddr.ipaddr,
return -1;
}
- if (fr_debug_flag > 1) {
+ if (fr_debug_lvl > 1) {
char type_buf[64];
char const *name = type_buf;
#ifdef WITH_UDPFROMTO
char dst_ip_buf[INET6_ADDRSTRLEN];
if ((packet->code >= PW_DHCP_DISCOVER) &&
- (packet->code <= PW_DHCP_INFORM)) {
+ (packet->code < (1024 + DHCP_MAX_MESSAGE_TYPE))) {
name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
} else {
snprintf(type_buf, sizeof(type_buf), "%d",
DEBUG(
#ifdef WITH_UDPFROMTO
- "Sending %s of id %08x from %s:%d to %s:%d\n",
+ "Sending %s Id %08x from %s:%d to %s:%d\n",
#else
- "Sending %s of id %08x to %s:%d\n",
+ "Sending %s Id %08x to %s:%d\n",
#endif
name, (unsigned int) packet->id,
#ifdef WITH_UDPFROMTO
#endif
}
-static int fr_dhcp_attr2vp(RADIUS_PACKET *packet, VALUE_PAIR *vp, uint8_t const *p, size_t alen);
+static int fr_dhcp_attr2vp(TALLOC_CTX *ctx, VALUE_PAIR **vp_p, uint8_t const *p, size_t alen);
+
+/** Returns the number of array members for arrays with fixed element sizes
+ *
+ */
+static int fr_dhcp_array_members(size_t *len, DICT_ATTR const *da)
+{
+ int num_entries = 1;
+
+ /*
+ * Could be an array of bytes, integers, etc.
+ */
+ if (da->flags.array) switch (da->type) {
+ case PW_TYPE_BYTE:
+ num_entries = *len;
+ *len = 1;
+ break;
+
+ case PW_TYPE_SHORT: /* ignore any trailing data */
+ num_entries = *len >> 1;
+ *len = 2;
+ break;
+
+ case PW_TYPE_IPV4_ADDR:
+ case PW_TYPE_INTEGER:
+ case PW_TYPE_DATE: /* ignore any trailing data */
+ num_entries = *len >> 2;
+ *len = 4;
+ break;
+
+ case PW_TYPE_IPV6_ADDR:
+ num_entries = *len >> 4;
+ *len = 16;
+ break;
+
+ default:
+ break;
+ }
+
+ return num_entries;
+}
+
+/** RFC 4243 Vendor Specific Suboptions
+ *
+ * Vendor specific suboptions are in the format.
+ @verbatim
+ 0 1 2 3
+ 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Enterprise Number 0 |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Len 0 | /
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ / Suboption Data 0 /
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Enterprise Number n |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ | Len n | /
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ / Suboption Data n /
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ @endverbatim
+ *
+ * So although the vendor is identified, the format of the data isn't
+ * specified so we can't actually resolve the suboption to an
+ * attribute. For now, we just convert it to an attribute of
+ * DHCP-Vendor-Specific-Information with raw octets contents.
+ */
+
-static int decode_tlv(RADIUS_PACKET *packet, VALUE_PAIR *tlv, uint8_t const *data, size_t data_len)
+/** Decode DHCP suboptions
+ *
+ * @param[in,out] tlv to decode. *tlv will be set to the head of the list of suboptions and original will be freed.
+ * @param[in] ctx context to alloc new attributes in.
+ * @param[in] data to parse.
+ * @param[in] len length of data to parse.
+ */
+static int fr_dhcp_decode_suboption(TALLOC_CTX *ctx, VALUE_PAIR **tlv, uint8_t const *data, size_t len)
{
- uint8_t const *p;
+ uint8_t const *p, *q;
VALUE_PAIR *head, *vp;
vp_cursor_t cursor;
/*
+ * TLV must already point to a VALUE_PAIR.
+ */
+ VERIFY_VP(*tlv);
+
+ /*
* Take a pass at parsing it.
*/
p = data;
- while (p < (data + data_len)) {
- if ((p + 2) > (data + data_len)) goto make_tlv;
+ q = data + len;
+ while (p < q) {
+ /*
+ * RFC 3046 is very specific about not allowing termination
+ * with a 255 sub-option. But it's required for decoding
+ * option 43, and vendors will probably screw it up
+ * anyway.
+ */
+ if (*p == 0) {
+ p++;
+ continue;
+ }
+ if (*p == 255) {
+ q--;
+ break;
+ }
- if ((p + p[1] + 2) > (data + data_len)) goto make_tlv;
- p += 2 + p[1];
+ /*
+ * Check if reading length would take us past the end of the buffer
+ */
+ if (++p >= q) goto malformed;
+ p += p[0];
+
+ /*
+ * Check if length > the length of the buffer we have left
+ */
+ if (p >= q) goto malformed;
+ p++;
}
/*
* Got here... must be well formed.
*/
head = NULL;
- paircursor(&cursor, &head);
+ fr_cursor_init(&cursor, &head);
p = data;
- while (p < (data + data_len)) {
- vp = paircreate(packet, tlv->da->attr | (p[0] << 8), DHCP_MAGIC_VENDOR);
- if (!vp) {
- pairfree(&head);
- goto make_tlv;
+ while (p < q) {
+ uint8_t const *a_p;
+ size_t a_len;
+ int num_entries, i;
+
+ DICT_ATTR const *da;
+ uint32_t attr;
+
+ /*
+ * Not enough room for the option header, it's a
+ * bad packet.
+ */
+ if ((p + 2) > (data + len)) {
+ fr_pair_list_free(&head);
+ return -1;
}
- if (fr_dhcp_attr2vp(packet, vp, p + 2, p[1]) < 0) {
- pairfree(&head);
- goto make_tlv;
+ /*
+ * Not enough room for the option header + data,
+ * it's a bad packet.
+ */
+ if ((p + 2 + p[1]) > (data + len)) {
+ fr_pair_list_free(&head);
+ return -1;
+ }
+
+ /*
+ * The initial OID string looks like:
+ * <iana>.0
+ *
+ * If <iana>.0 is type TLV then we attempt to decode its contents as more
+ * DHCP suboptions, which gives us:
+ * <iana>.<attr>
+ *
+ * If <iana>.0 is not defined in the dictionary or is type octets, we leave
+ * the attribute as is.
+ */
+ attr = (*tlv)->da->attr ? ((*tlv)->da->attr | (p[0] << 8)) : p[0];
+
+ /*
+ * Use the vendor of the parent TLV which is not necessarily
+ * DHCP_MAGIC_VENDOR.
+ *
+ * Note: This does not deal with dictionary numbering clashes. If
+ * the vendor uses different numbers for DHCP suboptions and RADIUS
+ * attributes then it's time to break out %{hex:} and regular
+ * expressions.
+ */
+ da = dict_attrbyvalue(attr, (*tlv)->da->vendor);
+ if (!da) {
+ da = dict_unknown_afrom_fields(ctx, attr, (*tlv)->da->vendor);
+ if (!da) {
+ fr_pair_list_free(&head);
+ return -1;
+ }
}
- pairinsert(&cursor, vp);
- p += 2 + p[1];
+ a_len = p[1];
+ a_p = p + 2;
+ num_entries = fr_dhcp_array_members(&a_len, da);
+ for (i = 0; i < num_entries; i++) {
+ vp = fr_pair_afrom_da(ctx, da);
+ if (!vp) {
+ fr_pair_list_free(&head);
+ return -1;
+ }
+ vp->op = T_OP_EQ;
+ fr_pair_steal(ctx, vp); /* for unknown attributes hack */
+
+ if (fr_dhcp_attr2vp(ctx, &vp, a_p, a_len) < 0) {
+ dict_attr_free(&da);
+ fr_pair_list_free(&head);
+ goto malformed;
+ }
+ fr_cursor_merge(&cursor, vp);
+
+ a_p += a_len;
+ }
+
+ dict_attr_free(&da); /* for unknown attributes hack */
+
+ p += 2 + p[1]; /* code (1) + len (1) + suboption len (n)*/
}
/*
- * The caller allocated TLV, so we need to copy the FIRST
- * attribute over top of that.
+ * The caller allocated a TLV, if decoding it generated
+ * additional attributes, we now need to free it, and write
+ * the HEAD of our new list of attributes in its place.
*/
if (head) {
- memcpy(tlv, head, sizeof(*tlv));
- head->next = NULL;
- pairfree(&head);
+ vp_cursor_t tlv_cursor;
+
+ /*
+ * Free the old TLV attribute
+ */
+ TALLOC_FREE(*tlv);
+
+ /*
+ * Cursor not necessary but means we don't have to set
+ * ->next directly.
+ */
+ fr_cursor_init(&tlv_cursor, tlv);
+ fr_cursor_merge(&tlv_cursor, head);
}
return 0;
-make_tlv:
- tlv->vp_tlv = talloc_array(tlv, uint8_t, data_len);
- if (!tlv->vp_tlv) {
- fr_strerror_printf("No memory");
- return -1;
- }
- memcpy(tlv->vp_tlv, data, data_len);
- tlv->length = data_len;
+malformed:
+ fr_pair_to_unknown(*tlv);
+ fr_pair_value_memcpy(*tlv, data, len);
return 0;
}
-
/*
* Decode ONE value into a VP
*/
-static int fr_dhcp_attr2vp(RADIUS_PACKET *packet, VALUE_PAIR *vp, uint8_t const *p, size_t alen)
+static int fr_dhcp_attr2vp(TALLOC_CTX *ctx, VALUE_PAIR **vp_p, uint8_t const *data, size_t len)
{
- char *q;
+ VALUE_PAIR *vp = *vp_p;
+ VERIFY_VP(vp);
switch (vp->da->type) {
case PW_TYPE_BYTE:
- if (alen != 1) goto raw;
- vp->vp_integer = p[0];
+ if (len != 1) goto raw;
+ vp->vp_byte = data[0];
break;
case PW_TYPE_SHORT:
- if (alen != 2) goto raw;
- memcpy(&vp->vp_integer, p, 2);
- vp->vp_integer = ntohs(vp->vp_integer);
+ if (len != 2) goto raw;
+ memcpy(&vp->vp_short, data, 2);
+ vp->vp_short = ntohs(vp->vp_short);
break;
case PW_TYPE_INTEGER:
- if (alen != 4) goto raw;
- memcpy(&vp->vp_integer, p, 4);
+ if (len != 4) goto raw;
+ memcpy(&vp->vp_integer, data, 4);
vp->vp_integer = ntohl(vp->vp_integer);
break;
- case PW_TYPE_IPADDR:
- if (alen != 4) goto raw;
+ case PW_TYPE_IPV4_ADDR:
+ if (len != 4) goto raw;
/*
* Keep value in Network Order!
*/
- memcpy(&vp->vp_ipaddr, p , 4);
- vp->length = 4;
+ memcpy(&vp->vp_ipaddr, data, 4);
+ vp->vp_length = 4;
break;
+ /*
+ * In DHCPv4, string options which can also be arrays,
+ * have their values '\0' delimited.
+ */
case PW_TYPE_STRING:
- vp->vp_strvalue = q = talloc_array(vp, char, alen + 1);
- vp->type = VT_DATA;
- memcpy(q, p , alen);
- q[alen] = '\0';
+ {
+ uint8_t const *p;
+ uint8_t const *q, *end;
+ vp_cursor_t cursor;
+
+ p = data;
+ q = end = data + len;
+
+ if (!vp->da->flags.array) {
+ fr_pair_value_bstrncpy(vp, (char const *)p, q - p);
+ break;
+ }
+
+ /*
+ * Initialise the cursor as we may be inserting
+ * multiple additional VPs
+ */
+ fr_cursor_init(&cursor, vp_p);
+ while (p < end) {
+ q = memchr(p, '\0', end - p);
+ /* Malformed but recoverable */
+ if (!q) q = end;
+
+ fr_pair_value_bstrncpy(vp, (char const *)p, q - p);
+ p = q + 1;
+
+ if (p >= end) break;
+
+ /* Need another VP for the next round */
+ vp = fr_pair_afrom_da(ctx, vp->da);
+ if (!vp) {
+ fr_pair_list_free(vp_p);
+ return -1;
+ }
+ fr_cursor_insert(&cursor, vp);
+ }
+ }
break;
case PW_TYPE_ETHERNET:
- memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
- vp->length = sizeof(vp->vp_ether);
+ memcpy(vp->vp_ether, data, sizeof(vp->vp_ether));
+ vp->vp_length = sizeof(vp->vp_ether);
break;
/*
* vp's original DICT_ATTR with an unknown one.
*/
raw:
- if (pair2unknown(vp) < 0) return -1;
+ if (fr_pair_to_unknown(vp) < 0) return -1;
case PW_TYPE_OCTETS:
- if (alen > 253) return -1;
- pairmemcpy(vp, p, alen);
+ if (len > 255) return -1;
+ fr_pair_value_memcpy(vp, data, len);
break;
+ /*
+ * For option 82 et al...
+ */
case PW_TYPE_TLV:
- return decode_tlv(packet, vp, p, alen);
+ return fr_dhcp_decode_suboption(ctx, vp_p, data, len);
default:
fr_strerror_printf("Internal sanity check %d %d", vp->da->type, __LINE__);
return -1;
} /* switch over type */
- vp->length = alen;
+ vp->vp_length = len;
return 0;
}
-ssize_t fr_dhcp_decode_options(RADIUS_PACKET *packet,
- uint8_t const *data, size_t len, VALUE_PAIR **head)
+/** Decode DHCP options
+ *
+ * @param[in,out] out Where to write the decoded options.
+ * @param[in] ctx context to alloc new attributes in.
+ * @param[in] data to parse.
+ * @param[in] len of data to parse.
+ */
+ssize_t fr_dhcp_decode_options(TALLOC_CTX *ctx, VALUE_PAIR **out, uint8_t const *data, size_t len)
{
- int i;
VALUE_PAIR *vp;
vp_cursor_t cursor;
- uint8_t const *p, *next;
- next = data;
+ uint8_t const *p, *q;
- *head = NULL;
- paircursor(&cursor, head);
+ *out = NULL;
+ fr_cursor_init(&cursor, out);
/*
* FIXME: This should also check sname && file fields.
* See the dhcp_get_option() function above.
*/
- while (next < (data + len)) {
- int num_entries, alen;
- DICT_ATTR const *da;
-
- p = next;
-
- if (*p == 0) break;
- if (*p == 255) break; /* end of options signifier */
- if ((p + 2) > (data + len)) break;
+ p = data;
+ q = data + len;
+ while (p < q) {
+ uint8_t const *a_p;
+ size_t a_len;
+ int num_entries, i;
- next = p + 2 + p[1];
+ DICT_ATTR const *da;
- if (p[1] >= 253) {
- fr_strerror_printf("Attribute too long %u %u",
- p[0], p[1]);
+ if (*p == 0) { /* 0x00 - Padding option */
+ p++;
continue;
}
- da = dict_attrbyvalue(p[0], DHCP_MAGIC_VENDOR);
- if (!da) {
- fr_strerror_printf("Attribute not in our dictionary: %u",
- p[0]);
- continue;
+ if (*p == 255) { /* 0xff - End of options signifier */
+ break;
}
- vp = NULL;
- num_entries = 1;
- alen = p[1];
- p += 2;
+ if ((p + 2) > q) break;
+
+ a_len = p[1];
+ a_p = p + 2;
/*
- * Could be an array of bytes, integers, etc.
+ * Ensure we've not been given a bad length value
*/
- if (da->flags.array) {
- switch (da->type) {
- case PW_TYPE_BYTE:
- num_entries = alen;
- alen = 1;
- break;
-
- case PW_TYPE_SHORT: /* ignore any trailing data */
- num_entries = alen >> 1;
- alen = 2;
- break;
-
- case PW_TYPE_IPADDR:
- case PW_TYPE_INTEGER:
- case PW_TYPE_DATE: /* ignore any trailing data */
- num_entries = alen >> 2;
- alen = 4;
- break;
-
- default:
+ if ((a_p + a_len) > q) {
+ fr_strerror_printf("Length field value of option %u is incorrect. "
+ "Got %u bytes, expected <= %zu bytes", p[0], p[1], q - a_p);
+ fr_pair_list_free(out);
+ return -1;
+ }
- break; /* really an internal sanity failure */
+ /*
+ * Unknown attribute, create an octets type
+ * attribute with the contents of the sub-option.
+ */
+ da = dict_attrbyvalue(p[0], DHCP_MAGIC_VENDOR);
+ if (!da) {
+ da = dict_unknown_afrom_fields(ctx, p[0], DHCP_MAGIC_VENDOR);
+ if (!da) {
+ fr_pair_list_free(out);
+ return -1;
}
+ vp = fr_pair_afrom_da(ctx, da);
+ if (!vp) {
+ fr_pair_list_free(out);
+ return -1;
+ }
+ fr_pair_value_memcpy(vp, a_p, a_len);
+ fr_cursor_insert(&cursor, vp);
+
+ goto next;
}
/*
- * Loop over all of the entries, building VPs
+ * Array type sub-option create a new VALUE_PAIR
+ * for each array element.
*/
+ num_entries = fr_dhcp_array_members(&a_len, da);
for (i = 0; i < num_entries; i++) {
- vp = pairmake(packet, NULL, da->name, NULL, T_OP_ADD);
+ vp = fr_pair_afrom_da(ctx, da);
if (!vp) {
- fr_strerror_printf("Cannot build attribute %s",
- fr_strerror());
- pairfree(head);
+ fr_pair_list_free(out);
return -1;
}
+ vp->op = T_OP_EQ;
- /*
- * Hack for ease of use.
- */
- if ((da->vendor == DHCP_MAGIC_VENDOR) &&
- (da->attr == 61) && !da->flags.array &&
- (alen == 7) && (*p == 1) && (num_entries == 1)) {
- pairmemcpy(vp, p + 1, 6);
-
- } else if (fr_dhcp_attr2vp(packet, vp, p, alen) < 0) {
- pairfree(&vp);
- pairfree(head);
+ if (fr_dhcp_attr2vp(ctx, &vp, a_p, a_len) < 0) {
+ fr_pair_list_free(&vp);
+ fr_pair_list_free(out);
return -1;
}
-
- pairinsert(&cursor, vp);
-
- for (vp = paircurrent(&cursor);
- vp;
- vp = pairnext(&cursor)) {
- debug_pair(vp);
- }
- p += alen;
+ fr_cursor_merge(&cursor, vp);
+ a_p += a_len;
} /* loop over array entries */
+ next:
+ p += 2 + p[1]; /* code (1) + len (1) + option len (n)*/
} /* loop over the entire packet */
- return next - data;
+ return p - data;
}
int fr_dhcp_decode(RADIUS_PACKET *packet)
VALUE_PAIR *head = NULL, *vp;
VALUE_PAIR *maxms, *mtu;
- paircursor(&cursor, &head);
+ fr_cursor_init(&cursor, &head);
p = packet->data;
- if ((fr_debug_flag > 2) && fr_log_fp) {
+ if ((fr_debug_lvl > 2) && fr_log_fp) {
for (i = 0; i < packet->data_len; i++) {
if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", (int) i);
fprintf(fr_log_fp, "%02x ", packet->data[i]);
fprintf(fr_log_fp, "\n");
}
- if (packet->data[1] != 1) {
+ if (packet->data[1] > 1) {
fr_strerror_printf("Packet is not Ethernet: %u",
packet->data[1]);
return -1;
* Decode the header.
*/
for (i = 0; i < 14; i++) {
- char *q;
- vp = pairmake(packet, NULL, dhcp_header_names[i], NULL, T_OP_EQ);
+ vp = fr_pair_make(packet, NULL, dhcp_header_names[i], NULL, T_OP_EQ);
if (!vp) {
char buffer[256];
strlcpy(buffer, fr_strerror(), sizeof(buffer));
fr_strerror_printf("Cannot decode packet due to internal error: %s", buffer);
- pairfree(&head);
+ fr_pair_list_free(&head);
return -1;
}
/*
- * If chaddr does != 6 bytes it's probably not ethernet, and we should store
+ * If chaddr != 6 bytes it's probably not ethernet, and we should store
* it as an opaque type (octets).
*/
- if ((i == 11) && (packet->data[1] == 1) && (packet->data[2] != sizeof(vp->vp_ether))) {
- DICT_ATTR const *da = dict_attrunknown(vp->da->attr, vp->da->vendor, true);
- if (!da) {
- return -1;
+ if (i == 11) {
+ /*
+ * Skip chaddr if it doesn't exist.
+ */
+ if ((packet->data[1] == 0) || (packet->data[2] == 0)) continue;
+
+ if ((packet->data[1] == 1) && (packet->data[2] != sizeof(vp->vp_ether))) {
+ DICT_ATTR const *da = dict_unknown_afrom_fields(packet, vp->da->attr, vp->da->vendor);
+ if (!da) {
+ return -1;
+ }
+ vp->da = da;
}
- vp->da = da;
}
switch (vp->da->type) {
case PW_TYPE_BYTE:
- vp->vp_integer = p[0];
- vp->length = 1;
+ vp->vp_byte = p[0];
+ vp->vp_length = 1;
break;
case PW_TYPE_SHORT:
- vp->vp_integer = (p[0] << 8) | p[1];
- vp->length = 2;
+ vp->vp_short = (p[0] << 8) | p[1];
+ vp->vp_length = 2;
break;
case PW_TYPE_INTEGER:
memcpy(&vp->vp_integer, p, 4);
vp->vp_integer = ntohl(vp->vp_integer);
- vp->length = 4;
+ vp->vp_length = 4;
break;
- case PW_TYPE_IPADDR:
+ case PW_TYPE_IPV4_ADDR:
memcpy(&vp->vp_ipaddr, p, 4);
- vp->length = 4;
+ vp->vp_length = 4;
break;
case PW_TYPE_STRING:
- vp->vp_strvalue = q = talloc_array(vp, char, dhcp_header_sizes[i] + 1);
- vp->type = VT_DATA;
- memcpy(q, p, dhcp_header_sizes[i]);
- q[dhcp_header_sizes[i]] = '\0';
- vp->length = strlen(vp->vp_strvalue);
- if (vp->length == 0) {
- pairfree(&vp);
+ /*
+ * According to RFC 2131, these are null terminated strings.
+ * We don't trust everyone to abide by the RFC, though.
+ */
+ if (*p != '\0') {
+ uint8_t *end;
+ int len;
+ end = memchr(p, '\0', dhcp_header_sizes[i]);
+ len = end ? end - p : dhcp_header_sizes[i];
+ fr_pair_value_bstrncpy(vp, p, len);
}
+ if (vp->vp_length == 0) fr_pair_list_free(&vp);
break;
case PW_TYPE_OCTETS:
- pairmemcpy(vp, p, packet->data[2]);
+ if (packet->data[2] == 0) break;
+
+ fr_pair_value_memcpy(vp, p, packet->data[2]);
break;
case PW_TYPE_ETHERNET:
memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
- vp->length = sizeof(vp->vp_ether);
+ vp->vp_length = sizeof(vp->vp_ether);
break;
default:
fr_strerror_printf("BAD TYPE %d", vp->da->type);
- pairfree(&vp);
+ fr_pair_list_free(&vp);
break;
}
p += dhcp_header_sizes[i];
if (!vp) continue;
debug_pair(vp);
- pairinsert(&cursor, vp);
+ fr_cursor_insert(&cursor, vp);
}
/*
*/
{
VALUE_PAIR *options = NULL;
+ vp_cursor_t options_cursor;
- if (fr_dhcp_decode_options(packet,
- packet->data + 240, packet->data_len - 240,
- &options) < 0) {
+ if (fr_dhcp_decode_options(packet, &options, packet->data + 240, packet->data_len - 240) < 0) {
return -1;
}
if (options) {
- pairinsert(&cursor, options);
+ for (vp = fr_cursor_init(&options_cursor, &options);
+ vp;
+ vp = fr_cursor_next(&options_cursor)) {
+ debug_pair(vp);
+ }
+ fr_cursor_merge(&cursor, options);
}
}
/*
* DHCP Opcode is request
*/
- vp = pairfind(head, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
+ vp = fr_pair_find_by_num(head, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
if (vp && vp->vp_integer == 3) {
/*
* Vendor is "MSFT 98"
*/
- vp = pairfind(head, 63, DHCP_MAGIC_VENDOR, TAG_ANY);
- if (vp && (strcmp(vp->vp_strvalue, "MSFT 98") == 0)) {
- vp = pairfind(head, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
+ vp = fr_pair_find_by_num(head, 60, DHCP_MAGIC_VENDOR, TAG_ANY);
+ if (vp && (vp->vp_length >= 7) && (memcmp(vp->vp_octets, "MSFT 98", 7) == 0)) {
+ vp = fr_pair_find_by_num(head, 262, DHCP_MAGIC_VENDOR, TAG_ANY);
/*
* Reply should be broadcast.
*/
- if (vp) vp->vp_integer |= 0x8000;
+ if (vp) vp->vp_short |= 0x8000;
packet->data[10] |= 0x80;
}
}
* Client can request a LARGER size, but not a smaller
* one. They also cannot request a size larger than MTU.
*/
- maxms = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
- mtu = pairfind(packet->vps, 26, DHCP_MAGIC_VENDOR, TAG_ANY);
+ maxms = fr_pair_find_by_num(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
+ mtu = fr_pair_find_by_num(packet->vps, 26, DHCP_MAGIC_VENDOR, TAG_ANY);
if (mtu && (mtu->vp_integer < DEFAULT_PACKET_SIZE)) {
- fr_strerror_printf("DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification.");
+ fr_strerror_printf("DHCP Fatal: Client says MTU is smaller than minimum permitted by the specification");
return -1;
}
maxms->vp_integer = mtu->vp_integer;
}
- if (fr_debug_flag) fflush(stdout);
+ if (fr_debug_lvl) fflush(stdout);
return 0;
}
-static int attr_cmp(void const *one, void const *two)
+int8_t fr_dhcp_attr_cmp(void const *a, void const *b)
{
- VALUE_PAIR const * const *a = one;
- VALUE_PAIR const * const *b = two;
+ VALUE_PAIR const *my_a = a;
+ VALUE_PAIR const *my_b = b;
+
+ VERIFY_VP(my_a);
+ VERIFY_VP(my_b);
/*
* DHCP-Message-Type is first, for simplicity.
*/
- if (((*a)->da->attr == 53) &&
- (*b)->da->attr != 53) return -1;
+ if ((my_a->da->attr == PW_DHCP_MESSAGE_TYPE) && (my_b->da->attr != PW_DHCP_MESSAGE_TYPE)) return -1;
+ if ((my_a->da->attr != PW_DHCP_MESSAGE_TYPE) && (my_b->da->attr == PW_DHCP_MESSAGE_TYPE)) return +1;
/*
* Relay-Agent is last
*/
- if (((*a)->da->attr == 82) &&
- (*b)->da->attr != 82) return 1;
+ if ((my_a->da->attr == PW_DHCP_OPTION_82) && (my_b->da->attr != PW_DHCP_OPTION_82)) return +1;
+ if ((my_a->da->attr != PW_DHCP_OPTION_82) && (my_b->da->attr == PW_DHCP_OPTION_82)) return -1;
+
+ if (my_a->da->attr < my_b->da->attr) return -1;
+ if (my_a->da->attr > my_b->da->attr) return 1;
- return ((*a)->da->attr - (*b)->da->attr);
+ return 0;
}
-/*
- * @todo Check room!
+/** Write DHCP option value into buffer
+ *
+ * Does not include DHCP option length or number.
+ *
+ * @param out where to write the DHCP option.
+ * @param outlen length of output buffer.
+ * @param vp option to encode.
+ * @return the length of data writen, -1 if out of buffer, -2 if unsupported type.
*/
-static size_t fr_dhcp_vp2attr(VALUE_PAIR *vp, uint8_t *p, UNUSED size_t room)
+static ssize_t fr_dhcp_vp2data(uint8_t *out, size_t outlen, VALUE_PAIR *vp)
{
- size_t length;
uint32_t lvalue;
+ uint8_t *p = out;
+
+ if (outlen < vp->vp_length) {
+ return -1;
+ }
- /*
- * Search for all attributes of the same
- * type, and pack them into the same
- * attribute.
- */
switch (vp->da->type) {
case PW_TYPE_BYTE:
- length = 1;
- *p = vp->vp_integer & 0xff;
+ *p = vp->vp_byte;
break;
case PW_TYPE_SHORT:
- length = 2;
- p[0] = (vp->vp_integer >> 8) & 0xff;
- p[1] = vp->vp_integer & 0xff;
+ p[0] = (vp->vp_short >> 8) & 0xff;
+ p[1] = vp->vp_short & 0xff;
break;
case PW_TYPE_INTEGER:
- length = 4;
lvalue = htonl(vp->vp_integer);
memcpy(p, &lvalue, 4);
break;
- case PW_TYPE_IPADDR:
- length = 4;
+ case PW_TYPE_IPV4_ADDR:
memcpy(p, &vp->vp_ipaddr, 4);
break;
case PW_TYPE_ETHERNET:
- length = 6;
- memcpy(p, &vp->vp_ether, 6);
+ memcpy(p, vp->vp_ether, 6);
break;
case PW_TYPE_STRING:
- memcpy(p, vp->vp_strvalue, vp->length);
- length = vp->length;
- break;
-
- case PW_TYPE_TLV: /* FIXME: split it on 255? */
- memcpy(p, vp->vp_tlv, vp->length);
- length = vp->length;
+ memcpy(p, vp->vp_strvalue, vp->vp_length);
break;
case PW_TYPE_OCTETS:
- memcpy(p, vp->vp_octets, vp->length);
- length = vp->length;
+ memcpy(p, vp->vp_octets, vp->vp_length);
break;
default:
- fr_strerror_printf("BAD TYPE2 %d", vp->da->type);
- length = 0;
- break;
+ fr_strerror_printf("Unsupported option type %d", vp->da->type);
+ return -2;
}
- return length;
+ return vp->vp_length;
}
-static VALUE_PAIR *fr_dhcp_vp2suboption(RADIUS_PACKET *packet, VALUE_PAIR *vps)
+/** Create a new TLV attribute from multiple sub options
+ *
+ * @param[in,out] out buffer to write the data
+ * @param[out] outlen length of the output buffer
+ * @param[in,out] cursor should be set to the start of the list of TLV attributes.
+ * Will be advanced to the first non-TLV attribute.
+ * @return length of data encoded, or -1 on error
+ */
+static ssize_t fr_dhcp_vp2data_tlv(uint8_t *out, ssize_t outlen, vp_cursor_t *cursor)
{
- int length;
- unsigned int attribute;
- uint8_t *ptr;
- vp_cursor_t cursor;
- VALUE_PAIR *vp, *tlv;
+ ssize_t len;
+ unsigned int parent; /* Parent attribute of suboption */
+ uint8_t attr = 0;
+ uint8_t *p, *opt_len;
+ vp_cursor_t tlv_cursor;
+ VALUE_PAIR *vp;
+
+#define SUBOPTION_PARENT(_x) (_x & 0xffff00ff)
+#define SUBOPTION_ATTR(_x) ((_x & 0xff00) >> 8)
- attribute = vps->da->attr & 0xffff00ff;
+ vp = fr_cursor_current(cursor);
+ if (!vp) return -1;
- tlv = paircreate(packet, attribute, DHCP_MAGIC_VENDOR);
- if (!tlv) return NULL;
+ parent = SUBOPTION_PARENT(vp->da->attr);
+
+ /*
+ * Remember where we started off.
+ */
+ fr_cursor_copy(&tlv_cursor, cursor);
+
+ /*
+ * Loop over TLVs to determine how much memory we need to allocate
+ *
+ * We advanced the tlv_cursor we were passed, so if we
+ * fail encoding, the tlv_cursor is at the right position
+ * for the next potentially encodable attr.
+ */
+ len = 0;
+ for (vp = fr_cursor_current(&tlv_cursor);
+ vp && vp->da->flags.is_tlv && (SUBOPTION_PARENT(vp->da->attr) == parent);
+ vp = fr_cursor_next(&tlv_cursor)) {
+ if (SUBOPTION_ATTR(vp->da->attr) == 0) {
+ fr_strerror_printf("Invalid attribute number 0");
+ return -1;
+ }
- tlv->length = 0;
- for (vp = paircursor(&cursor, &vps);
- vp;
- vp = pairnext(&cursor)) {
/*
- * Group the attributes ONLY until we see a
- * non-TLV attribute.
+ * If it's not an array type or is an array type,
+ * but is not the same as the previous attribute,
+ * we add 2 for the additional sub-option header
+ * bytes.
*/
- if (!vp->da->flags.is_tlv ||
- vp->da->flags.extended ||
- ((vp->da->attr & 0xffff00ff) != attribute)) {
- break;
+ if (!vp->da->flags.array || (SUBOPTION_ATTR(vp->da->attr) != attr)) {
+ attr = SUBOPTION_ATTR(vp->da->attr);
+ len += 2;
}
-
- tlv->length += vp->length + 2;
- }
-
- if (!tlv->length) {
- pairfree(&tlv);
- return NULL;
+ len += vp->vp_length;
}
- tlv->vp_tlv = talloc_array(tlv, uint8_t, tlv->length);
- if (!tlv->vp_tlv) {
- pairfree(&tlv);
- return NULL;
+ if (len > outlen) {
+ fr_strerror_printf("Insufficient room for suboption");
+ return -1;
}
- ptr = tlv->vp_tlv;
- for (vp = paircursor(&cursor, &vps);
- vp;
- vp = pairnext(&cursor)) {
- if (!vp->da->flags.is_tlv ||
- vp->da->flags.extended ||
- ((vp->da->attr & 0xffff00ff) != attribute)) {
- break;
+ attr = 0;
+ opt_len = NULL;
+ p = out;
+
+ for (vp = fr_cursor_current(cursor);
+ vp && vp->da->flags.is_tlv && (SUBOPTION_PARENT(vp->da->attr) == parent);
+ vp = fr_cursor_next(cursor)) {
+ /* Don't write out the header, were packing array options */
+ if (!opt_len || !vp->da->flags.array || (attr != SUBOPTION_ATTR(vp->da->attr))) {
+ attr = SUBOPTION_ATTR(vp->da->attr);
+ *p++ = attr;
+ opt_len = p++;
+ *opt_len = 0;
}
- length = fr_dhcp_vp2attr(vp, ptr + 2,
- tlv->vp_tlv + tlv->length - ptr);
- if (length > 255) {
- pairfree(&tlv);
- return NULL;
+ len = fr_dhcp_vp2data(p, out + outlen - p, vp);
+ if ((len < 0) || (len > 255)) {
+ return -1;
}
+ debug_pair(vp);
+ *opt_len += len;
+ p += len;
+ };
+
+ return p - out;
+}
+
+/** Encode a DHCP option and any sub-options.
+ *
+ * @param out Where to write encoded DHCP attributes.
+ * @param outlen Length of out buffer.
+ * @param ctx to use for any allocated memory.
+ * @param cursor with current VP set to the option to be encoded. Will be advanced to the next option to encode.
+ * @return > 0 length of data written, < 0 error, 0 not valid option (skipping).
+ */
+ssize_t fr_dhcp_encode_option(UNUSED TALLOC_CTX *ctx, uint8_t *out, size_t outlen, vp_cursor_t *cursor)
+{
+ VALUE_PAIR *vp;
+ DICT_ATTR const *previous;
+ uint8_t *opt_len, *p = out;
+ size_t freespace = outlen;
+ ssize_t len;
+
+ vp = fr_cursor_current(cursor);
+ if (!vp) return -1;
+
+ if (vp->da->vendor != DHCP_MAGIC_VENDOR) goto next; /* not a DHCP option */
+ if (vp->da->attr == PW_DHCP_MESSAGE_TYPE) goto next; /* already done */
+ if ((vp->da->attr > 255) && (DHCP_BASE_ATTR(vp->da->attr) != PW_DHCP_OPTION_82)) goto next;
+
+ if (vp->da->flags.extended) {
+ next:
+ fr_strerror_printf("Attribute \"%s\" is not a DHCP option", vp->da->name);
+ fr_cursor_next(cursor);
+ return 0;
+ }
+
+ /* Write out the option number */
+ *(p++) = vp->da->attr & 0xff;
+
+ /* Pointer to the length field of the option */
+ opt_len = p++;
+
+ /* Zero out the option's length field */
+ *opt_len = 0;
+
+ /* We just consumed two bytes for the header */
+ freespace -= 2;
+
+ /* DHCP options with the same number get coalesced into a single option */
+ do {
/*
- * Pack the attribute.
+ * Sub-option encoder will encode the data and
+ * advance the cursor.
*/
- ptr[0] = (vp->da->attr & 0xff00) >> 8;
- ptr[1] = length;
+ if (vp->da->flags.is_tlv) {
+ len = fr_dhcp_vp2data_tlv(p, freespace, cursor);
+ previous = NULL;
- ptr += length + 2;
- }
+ } else {
+ len = fr_dhcp_vp2data(p, freespace, vp);
+ if (len >= 0) debug_pair(vp);
+ fr_cursor_next(cursor);
+ previous = vp->da;
+ }
- return tlv;
-}
+ if (len < 0) return len;
+ if ((*opt_len + len) > 255) {
+ fr_strerror_printf("Skipping \"%s\": Option splitting not supported "
+ "(option > 255 bytes)", vp->da->name);
+ return 0;
+ }
+
+ p += len;
+ *opt_len += len;
+ freespace -= len;
+
+ } while ((vp = fr_cursor_current(cursor)) && previous && (previous == vp->da) && vp->da->flags.array);
+
+ return p - out;
+}
int fr_dhcp_encode(RADIUS_PACKET *packet)
{
- unsigned int i, num_vps;
+ unsigned int i;
uint8_t *p;
vp_cursor_t cursor;
VALUE_PAIR *vp;
uint32_t lvalue;
- size_t dhcp_size, length;
+ uint16_t svalue;
+ size_t dhcp_size;
+ ssize_t len;
#ifndef NDEBUG
char const *name;
# ifdef WITH_UDPFROMTO
/* XXX Ugly ... should be set by the caller */
if (packet->code == 0) packet->code = PW_DHCP_NAK;
+ /* store xid */
+ if ((vp = fr_pair_find_by_num(packet->vps, 260, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ packet->id = vp->vp_integer;
+ } else {
+ packet->id = fr_rand();
+ }
+
#ifndef NDEBUG
if ((packet->code >= PW_DHCP_DISCOVER) &&
- (packet->code <= PW_DHCP_INFORM)) {
+ (packet->code < (1024 + DHCP_MAX_MESSAGE_TYPE))) {
name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
} else {
name = "?Unknown?";
}
DEBUG(
-#ifdef WITH_UDPFROMTO
+# ifdef WITH_UDPFROMTO
"Encoding %s of id %08x from %s:%d to %s:%d\n",
-#else
+# else
"Encoding %s of id %08x to %s:%d\n",
-#endif
+# endif
name, (unsigned int) packet->id,
-#ifdef WITH_UDPFROMTO
+# ifdef WITH_UDPFROMTO
inet_ntop(packet->src_ipaddr.af,
&packet->src_ipaddr.ipaddr,
src_ip_buf, sizeof(src_ip_buf)),
packet->src_port,
-#endif
+# endif
inet_ntop(packet->dst_ipaddr.af,
&packet->dst_ipaddr.ipaddr,
dst_ip_buf, sizeof(dst_ip_buf)),
*/
/* DHCP-DHCP-Maximum-Msg-Size */
- vp = pairfind(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
+ vp = fr_pair_find_by_num(packet->vps, 57, DHCP_MAGIC_VENDOR, TAG_ANY);
if (vp && (vp->vp_integer > mms)) {
mms = vp->vp_integer;
}
#endif
- vp = pairfind(packet->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
+ vp = fr_pair_find_by_num(packet->vps, 256, DHCP_MAGIC_VENDOR, TAG_ANY);
if (vp) {
*p++ = vp->vp_integer & 0xff;
} else {
}
/* DHCP-Hardware-Type */
- if ((vp = pairfind(packet->vps, 257, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- *p++ = vp->vp_integer & 0xFF;
+ if ((vp = fr_pair_find_by_num(packet->vps, 257, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ *p++ = vp->vp_byte;
} else {
*p++ = 1; /* hardware type = ethernet */
}
/* DHCP-Hardware-Address-Length */
- if ((vp = pairfind(packet->vps, 258, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- *p++ = vp->vp_integer & 0xFF;
+ if ((vp = fr_pair_find_by_num(packet->vps, 258, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ *p++ = vp->vp_byte;
} else {
*p++ = 6; /* 6 bytes of ethernet */
}
/* DHCP-Hop-Count */
- if ((vp = pairfind(packet->vps, 259, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- *p = vp->vp_integer & 0xff;
+ if ((vp = fr_pair_find_by_num(packet->vps, 259, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ *p = vp->vp_byte;
}
p++;
/* DHCP-Transaction-Id */
- if ((vp = pairfind(packet->vps, 260, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- lvalue = htonl(vp->vp_integer);
- } else {
- lvalue = fr_rand();
- }
+ lvalue = htonl(packet->id);
memcpy(p, &lvalue, 4);
p += 4;
/* DHCP-Number-of-Seconds */
- if ((vp = pairfind(packet->vps, 261, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- lvalue = htonl(vp->vp_integer);
- memcpy(p, &lvalue, 2);
+ if ((vp = fr_pair_find_by_num(packet->vps, 261, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ svalue = htons(vp->vp_short);
+ memcpy(p, &svalue, 2);
}
p += 2;
/* DHCP-Flags */
- if ((vp = pairfind(packet->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- lvalue = htons(vp->vp_integer);
- memcpy(p, &lvalue, 2);
+ if ((vp = fr_pair_find_by_num(packet->vps, 262, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ svalue = htons(vp->vp_short);
+ memcpy(p, &svalue, 2);
}
p += 2;
/* DHCP-Client-IP-Address */
- if ((vp = pairfind(packet->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ if ((vp = fr_pair_find_by_num(packet->vps, 263, DHCP_MAGIC_VENDOR, TAG_ANY))) {
memcpy(p, &vp->vp_ipaddr, 4);
}
p += 4;
/* DHCP-Your-IP-address */
- if ((vp = pairfind(packet->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ if ((vp = fr_pair_find_by_num(packet->vps, 264, DHCP_MAGIC_VENDOR, TAG_ANY))) {
lvalue = vp->vp_ipaddr;
} else {
lvalue = htonl(INADDR_ANY);
p += 4;
/* DHCP-Server-IP-Address */
- vp = pairfind(packet->vps, 265, DHCP_MAGIC_VENDOR, TAG_ANY);
-
- /* DHCP-DHCP-Server-Identifier */
- if (!vp && (vp = pairfind(packet->vps, 54, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ vp = fr_pair_find_by_num(packet->vps, 265, DHCP_MAGIC_VENDOR, TAG_ANY);
+ if (vp) {
lvalue = vp->vp_ipaddr;
} else {
lvalue = htonl(INADDR_ANY);
/*
* DHCP-Gateway-IP-Address
*/
- if ((vp = pairfind(packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ if ((vp = fr_pair_find_by_num(packet->vps, 266, DHCP_MAGIC_VENDOR, TAG_ANY))) {
lvalue = vp->vp_ipaddr;
} else {
lvalue = htonl(INADDR_ANY);
p += 4;
/* DHCP-Client-Hardware-Address */
- if ((vp = pairfind(packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- if (vp->length == DHCP_CHADDR_LEN) {
- memcpy(p, vp->vp_ether, vp->length);
+ if ((vp = fr_pair_find_by_num(packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ if (vp->vp_length == sizeof(vp->vp_ether)) {
+ /*
+ * Ensure that we mark the packet as being Ethernet.
+ * This is mainly for DHCP-Lease-Query responses.
+ */
+ packet->data[1] = 1;
+ packet->data[2] = 6;
+
+ memcpy(p, vp->vp_ether, vp->vp_length);
} /* else ignore it */
}
p += DHCP_CHADDR_LEN;
/* DHCP-Server-Host-Name */
- if ((vp = pairfind(packet->vps, 268, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- if (vp->length > DHCP_SNAME_LEN) {
+ if ((vp = fr_pair_find_by_num(packet->vps, 268, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ if (vp->vp_length > DHCP_SNAME_LEN) {
memcpy(p, vp->vp_strvalue, DHCP_SNAME_LEN);
} else {
- memcpy(p, vp->vp_strvalue, vp->length);
+ memcpy(p, vp->vp_strvalue, vp->vp_length);
}
}
p += DHCP_SNAME_LEN;
*/
/* DHCP-Boot-Filename */
- if ((vp = pairfind(packet->vps, 269, DHCP_MAGIC_VENDOR, TAG_ANY))) {
- if (vp->length > DHCP_FILE_LEN) {
+ vp = fr_pair_find_by_num(packet->vps, 269, DHCP_MAGIC_VENDOR, TAG_ANY);
+ if (vp) {
+ if (vp->vp_length > DHCP_FILE_LEN) {
memcpy(p, vp->vp_strvalue, DHCP_FILE_LEN);
} else {
- memcpy(p, vp->vp_strvalue, vp->length);
+ memcpy(p, vp->vp_strvalue, vp->vp_length);
}
}
p += DHCP_FILE_LEN;
/*
* Print the header.
*/
- if (fr_debug_flag > 1) {
+ if (fr_debug_lvl > 1) {
uint8_t *pp = p;
p = packet->data;
for (i = 0; i < 14; i++) {
char *q;
- vp = pairmake(packet, NULL,
+ vp = fr_pair_make(packet, NULL,
dhcp_header_names[i], NULL, T_OP_EQ);
if (!vp) {
char buffer[256];
switch (vp->da->type) {
case PW_TYPE_BYTE:
- vp->vp_integer = p[0];
- vp->length = 1;
+ vp->vp_byte = p[0];
break;
case PW_TYPE_SHORT:
- vp->vp_integer = (p[0] << 8) | p[1];
- vp->length = 2;
+ vp->vp_short = (p[0] << 8) | p[1];
break;
case PW_TYPE_INTEGER:
memcpy(&vp->vp_integer, p, 4);
vp->vp_integer = ntohl(vp->vp_integer);
- vp->length = 4;
break;
- case PW_TYPE_IPADDR:
+ case PW_TYPE_IPV4_ADDR:
memcpy(&vp->vp_ipaddr, p, 4);
- vp->length = 4;
break;
case PW_TYPE_STRING:
- vp->vp_strvalue = q = talloc_array(vp, char, dhcp_header_sizes[i]);
+ vp->vp_strvalue = q = talloc_array(vp, char, dhcp_header_sizes[i] + 1);
vp->type = VT_DATA;
memcpy(q, p, dhcp_header_sizes[i]);
q[dhcp_header_sizes[i]] = '\0';
- vp->length = strlen(vp->vp_strvalue);
+ vp->vp_length = strlen(vp->vp_strvalue);
break;
case PW_TYPE_OCTETS: /* only for Client HW Address */
- pairmemcpy(vp, p, packet->data[2]);
+ fr_pair_value_memcpy(vp, p, packet->data[2]);
break;
case PW_TYPE_ETHERNET: /* only for Client HW Address */
memcpy(vp->vp_ether, p, sizeof(vp->vp_ether));
- vp->length = sizeof(vp->vp_ether);
break;
default:
fr_strerror_printf("Internal sanity check failed %d %d", vp->da->type, __LINE__);
- pairfree(&vp);
+ fr_pair_list_free(&vp);
break;
}
p += dhcp_header_sizes[i];
debug_pair(vp);
- pairfree(&vp);
+ fr_pair_list_free(&vp);
}
/*
p = pp;
}
- /*
- * Before packing the attributes, re-order them so that
- * the array ones are all contiguous. This simplifies
- * the later code.
- */
- num_vps = 0;
- for (vp = paircursor(&cursor, &packet->vps);
- vp;
- vp = pairnext(&cursor)) {
- num_vps++;
- }
- if (num_vps > 1) {
- VALUE_PAIR **array;
-
- array = talloc_array(packet, VALUE_PAIR*, num_vps);
-
- i = 0;
- for (vp = paircursor(&cursor, &packet->vps);
- vp;
- vp = pairnext(&cursor)) {
- array[i++] = vp;
- }
-
- /*
- * Sort the attributes.
- */
- qsort(array, (size_t) num_vps, sizeof(VALUE_PAIR *), attr_cmp);
-
- packet->vps = NULL;
- paircursor(&cursor, &packet->vps);
- for (i = 0; i < num_vps; i++) {
- array[i]->next = NULL;
- pairinsert(&cursor, array[i]);
- }
- talloc_free(array);
- }
-
p[0] = 0x35; /* DHCP-Message-Type */
p[1] = 1;
p[2] = packet->code - PW_DHCP_OFFSET;
p += 3;
/*
- * Pack in the attributes.
+ * Pre-sort attributes into contiguous blocks so that fr_dhcp_encode_option
+ * operates correctly. This changes the order of the list, but never mind...
*/
- vp = packet->vps;
- while (vp) {
- unsigned int num_entries = 1;
- VALUE_PAIR *same;
- uint8_t *plength;
-
- if (vp->da->vendor != DHCP_MAGIC_VENDOR) goto next;
- if (vp->da->attr == 53) goto next; /* already done */
- if ((vp->da->attr > 255) &&
- (DHCP_BASE_ATTR(vp->da->attr) != PW_DHCP_OPTION_82)) goto next;
-
- debug_pair(vp);
- if (vp->da->flags.extended) goto next;
-
- for (same = paircursor(&cursor, &vp->next);
- same;
- same = pairnext(&cursor)) {
- if (same->da->attr != vp->da->attr) break;
- num_entries++;
- }
-
- /*
- * For client-identifier
- * @todo What's this meant to be doing?!
- */
-#if 0
- if ((vp->da->type == PW_TYPE_ETHERNET) &&
- (vp->length == 6) &&
- (num_entries == 1)) {
- vp->da->type = PW_TYPE_OCTETS;
- memmove(vp->vp_octets + 1, vp->vp_octets, 6);
- vp->vp_octets[0] = 1;
- }
-#endif
- *(p++) = vp->da->attr & 0xff;
- plength = p;
- *(p++) = 0; /* header isn't included in attr length */
-
- for (i = 0; i < num_entries; i++) {
- if (i != 0) debug_pair(vp);
-
- if (vp->da->flags.is_tlv) {
- VALUE_PAIR *tlv;
-
- /*
- * Should NOT have been encoded yet!
- */
- tlv = fr_dhcp_vp2suboption(packet, vp);
-
- /*
- * Ignore it if there's an issue
- * encoding it.
- */
- if (!tlv) goto next;
-
- tlv->next = vp->next;
- vp->next = tlv;
- vp = tlv;
- }
-
- length = fr_dhcp_vp2attr(vp, p, 0);
+ fr_pair_list_sort(&packet->vps, fr_dhcp_attr_cmp);
+ fr_cursor_init(&cursor, &packet->vps);
- /*
- * This will never happen due to FreeRADIUS
- * limitations: sizeof(vp->vp_octets) < 255
- */
- if (length > 255) {
- fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
- break;
- }
-
- /*
- * More than one attribute of the same type
- * in a row: they are packed together
- * into the same TLV. If we overflow,
- * go bananas!
- */
- if ((*plength + length) > 255) {
- fr_strerror_printf("WARNING Ignoring too long attribute %s!", vp->da->name);
- break;
- }
-
- *plength += length;
- p += length;
-
- if (vp->next &&
- (vp->next->da->attr == vp->da->attr))
- vp = vp->next;
- } /* loop over num_entries */
-
- next:
- vp = vp->next;
- }
+ /*
+ * Each call to fr_dhcp_encode_option will encode one complete DHCP option,
+ * and sub options.
+ */
+ while ((vp = fr_cursor_current(&cursor))) {
+ len = fr_dhcp_encode_option(packet, p, packet->data_len - (p - packet->data), &cursor);
+ if (len < 0) break;
+ p += len;
+ };
p[0] = 0xff; /* end of option option */
p[1] = 0x00;
packet->data_len = DEFAULT_PACKET_SIZE;
}
- if ((fr_debug_flag > 2) && fr_log_fp) {
+ if ((fr_debug_lvl > 2) && fr_log_fp) {
fprintf(fr_log_fp, "DHCP Sending %zu bytes\n", packet->data_len);
for (i = 0; i < packet->data_len; i++) {
- if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", i);
+ if ((i & 0x0f) == 0x00) fprintf(fr_log_fp, "%d: ", (int) i);
fprintf(fr_log_fp, "%02x ", packet->data[i]);
if ((i & 0x0f) == 0x0f) fprintf(fr_log_fp, "\n");
}
struct sockaddr_in *sin;
struct arpreq req;
+ if (!interface) {
+ fr_strerror_printf("No interface specified. Cannot update ARP table");
+ return -1;
+ }
+
if (!fr_assert(macaddr) ||
!fr_assert((macaddr->da->type == PW_TYPE_ETHERNET) || (macaddr->da->type == PW_TYPE_OCTETS))) {
- fr_strerror_printf("Wrong VP type (%s) for chaddr",
- fr_int2str(dict_attr_types, macaddr->da->type, "<invalid>"));
+ fr_strerror_printf("Wrong VP type (%s) for chaddr",
+ fr_int2str(dict_attr_types, macaddr->da->type, "<invalid>"));
return -1;
}
- if (macaddr->length > sizeof(req.arp_ha.sa_data)) {
+ if (macaddr->vp_length > sizeof(req.arp_ha.sa_data)) {
fr_strerror_printf("arp sa_data field too small (%zu octets) to contain chaddr (%zu octets)",
- sizeof(req.arp_ha.sa_data), macaddr->length);
+ sizeof(req.arp_ha.sa_data), macaddr->vp_length);
return -1;
}
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = ip->vp_ipaddr;
- if (interface) {
- strlcpy(req.arp_dev, interface, sizeof(req.arp_dev));
- }
+ strlcpy(req.arp_dev, interface, sizeof(req.arp_dev));
if (macaddr->da->type == PW_TYPE_ETHERNET) {
- memcpy(&req.arp_ha.sa_data, &macaddr->vp_ether, sizeof(macaddr->vp_ether));
+ memcpy(&req.arp_ha.sa_data, macaddr->vp_ether, sizeof(macaddr->vp_ether));
} else {
- memcpy(&req.arp_ha.sa_data, macaddr->vp_octets, macaddr->length);
+ memcpy(&req.arp_ha.sa_data, macaddr->vp_octets, macaddr->vp_length);
}
req.arp_flags = ATF_COM;
if (ioctl(fd, SIOCSARP, &req) < 0) {
- fr_strerror_printf("Failed to add entry in ARP cache: %s (%d)", strerror(errno), errno);
+ fr_strerror_printf("Failed to add entry in ARP cache: %s (%d)", fr_syserror(errno), errno);
return -1;
}
return -1;
}
#endif
+
+
+#ifdef HAVE_LINUX_IF_PACKET_H
+/*
+ * Open a packet interface raw socket.
+ * Bind it to the specified interface using a device independent physical layer address.
+ */
+int fr_socket_packet(int iface_index, struct sockaddr_ll *p_ll)
+{
+ int lsockfd;
+
+ /* PF_PACKET - packet interface on device level.
+ using a raw socket allows packet data to be unchanged by the device driver.
+ */
+ lsockfd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
+ if (lsockfd < 0) {
+ fr_strerror_printf("cannot open socket: %s", fr_syserror(errno));
+ return lsockfd;
+ }
+
+ /* Set link layer parameters */
+ memset(p_ll, 0, sizeof(struct sockaddr_ll));
+
+ p_ll->sll_family = AF_PACKET;
+ p_ll->sll_protocol = htons(ETH_P_ALL);
+ p_ll->sll_ifindex = iface_index;
+ p_ll->sll_hatype = ARPHRD_ETHER;
+ p_ll->sll_pkttype = PACKET_OTHERHOST;
+ p_ll->sll_halen = 6;
+
+ if (bind(lsockfd, (struct sockaddr *)p_ll, sizeof(struct sockaddr_ll)) < 0) {
+ close(lsockfd);
+ fr_strerror_printf("cannot bind raw socket: %s", fr_syserror(errno));
+ return -1;
+ }
+
+ return lsockfd;
+}
+
+/*
+ * Encode and send a DHCP packet on a raw packet socket.
+ */
+int fr_dhcp_send_raw_packet(int sockfd, struct sockaddr_ll *p_ll, RADIUS_PACKET *packet)
+{
+ VALUE_PAIR *vp;
+ u_char dhcp_packet[1518] = { 0 };
+
+ /* set ethernet source address to our MAC address (DHCP-Client-Hardware-Address). */
+ u_char dhmac[ETH_ADDR_LEN] = { 0 };
+ if ((vp = fr_pair_find_by_num(packet->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY))) {
+ if (vp->length == sizeof(vp->vp_ether)) {
+ memcpy(dhmac, vp->vp_ether, vp->length);
+ }
+ }
+
+ /* fill in Ethernet layer (L2) */
+ struct ethernet_header *ethhdr = (struct ethernet_header *)dhcp_packet;
+ memcpy(ethhdr->ether_dst, eth_bcast, ETH_ADDR_LEN);
+ memcpy(ethhdr->ether_src, dhmac, ETH_ADDR_LEN);
+ ethhdr->ether_type = htons(ETH_TYPE_IP);
+
+ /* fill in IP layer (L3) */
+ struct ip_header *iph = (struct ip_header *)(dhcp_packet + ETH_HDR_SIZE);
+ iph->ip_vhl = IP_VHL(4, 5);
+ iph->ip_tos = 0;
+ iph->ip_len = htons(IP_HDR_SIZE + UDP_HDR_SIZE + packet->data_len);
+ iph->ip_id = 0;
+ iph->ip_off = 0;
+ iph->ip_ttl = 64;
+ iph->ip_p = 17;
+ iph->ip_sum = 0; /* Filled later */
+
+ /* saddr: Packet-Src-IP-Address (default: 0.0.0.0). */
+ iph->ip_src.s_addr = packet->src_ipaddr.ipaddr.ip4addr.s_addr;
+
+ /* daddr: packet destination IP addr (should be 255.255.255.255 for broadcast). */
+ iph->ip_dst.s_addr = packet->dst_ipaddr.ipaddr.ip4addr.s_addr;
+
+ /* IP header checksum */
+ iph->ip_sum = fr_iph_checksum((uint8_t const *)iph, 5);
+
+ /* fill in UDP layer (L4) */
+ udp_header_t *uh = (udp_header_t *) (dhcp_packet + ETH_HDR_SIZE + IP_HDR_SIZE);
+
+ uh->src = htons(68);
+ uh->dst = htons(67);
+ u_int16_t l4_len = (UDP_HDR_SIZE + packet->data_len);
+ uh->len = htons(l4_len);
+ uh->checksum = 0; /* UDP checksum will be done after dhcp header */
+
+ /* DHCP layer (L7) */
+ dhcp_packet_t *dhpointer = (dhcp_packet_t *)(dhcp_packet + ETH_HDR_SIZE + IP_HDR_SIZE + UDP_HDR_SIZE);
+ /* just copy what FreeRADIUS has encoded for us. */
+ memcpy(dhpointer, packet->data, packet->data_len);
+
+ /* UDP checksum is done here */
+ uh->checksum = fr_udp_checksum((uint8_t const *)(dhcp_packet + ETH_HDR_SIZE + IP_HDR_SIZE), ntohs(uh->len), uh->checksum,
+ packet->src_ipaddr.ipaddr.ip4addr, packet->dst_ipaddr.ipaddr.ip4addr);
+
+ if (fr_debug_lvl > 1) {
+ char type_buf[64];
+ char const *name = type_buf;
+ char src_ip_buf[INET6_ADDRSTRLEN];
+ char dst_ip_buf[INET6_ADDRSTRLEN];
+
+ if ((packet->code >= PW_DHCP_DISCOVER) &&
+ (packet->code < (1024 + DHCP_MAX_MESSAGE_TYPE))) {
+ name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
+ } else {
+ snprintf(type_buf, sizeof(type_buf), "%d",
+ packet->code - PW_DHCP_OFFSET);
+ }
+
+ DEBUG(
+ "Sending %s Id %08x from %s:%d to %s:%d\n",
+ name, (unsigned int) packet->id,
+ inet_ntop(packet->src_ipaddr.af, &packet->src_ipaddr.ipaddr, src_ip_buf, sizeof(src_ip_buf)), packet->src_port,
+ inet_ntop(packet->dst_ipaddr.af, &packet->dst_ipaddr.ipaddr, dst_ip_buf, sizeof(dst_ip_buf)), packet->dst_port);
+ }
+
+ return sendto(sockfd, dhcp_packet,
+ (ETH_HDR_SIZE + IP_HDR_SIZE + UDP_HDR_SIZE + packet->data_len),
+ 0, (struct sockaddr *) p_ll, sizeof(struct sockaddr_ll));
+}
+
+/*
+ * print an ethernet address in a buffer
+ */
+char * ether_addr_print(const uint8_t *addr, char *buf)
+{
+ sprintf (buf, "%02x:%02x:%02x:%02x:%02x:%02x",
+ addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+ return buf;
+}
+
+/*
+ * For a client, receive a DHCP packet from a raw packet
+ * socket. Make sure it matches the ongoing request.
+ *
+ * FIXME: split this into two, recv_raw_packet, and verify(packet, original)
+ */
+RADIUS_PACKET *fr_dhcp_recv_raw_packet(int sockfd, struct sockaddr_ll *p_ll, RADIUS_PACKET *request)
+{
+ VALUE_PAIR *vp;
+ RADIUS_PACKET *packet;
+ uint8_t *code;
+ uint32_t magic, xid;
+ ssize_t data_len;
+
+ uint8_t *raw_packet;
+ ethernet_header_t *eth_hdr;
+ struct ip_header *ip_hdr;
+ udp_header_t *udp_hdr;
+ dhcp_packet_t *dhcp_hdr;
+ uint16_t udp_src_port;
+ uint16_t udp_dst_port;
+ size_t dhcp_data_len;
+ int retval;
+ socklen_t sock_len;
+ fd_set read_fd;
+
+ packet = rad_alloc(NULL, false);
+ if (!packet) {
+ fr_strerror_printf("Failed allocating packet");
+ return NULL;
+ }
+
+ raw_packet = talloc_zero_array(packet, uint8_t, MAX_PACKET_SIZE);
+ if (!raw_packet) {
+ fr_strerror_printf("Out of memory");
+ rad_free(&packet);
+ return NULL;
+ }
+
+ packet->sockfd = sockfd;
+
+ /* a packet was received (but maybe it is not for us) */
+ sock_len = sizeof(struct sockaddr_ll);
+ data_len = recvfrom(sockfd, raw_packet, MAX_PACKET_SIZE, 0,
+ (struct sockaddr *)p_ll, &sock_len);
+
+ uint8_t data_offset = ETH_HDR_SIZE + IP_HDR_SIZE + UDP_HDR_SIZE; // DHCP data starts after Ethernet, IP, UDP.
+
+ if (data_len <= data_offset) DISCARD_RP("Payload (%d) smaller than required for layers 2+3+4", (int)data_len);
+
+ /* map raw packet to packet header of the different layers (Ethernet, IP, UDP) */
+ eth_hdr = (ethernet_header_t *)raw_packet;
+
+ /* a. Check Ethernet layer data (L2) */
+ if (ntohs(eth_hdr->ether_type) != ETH_TYPE_IP) DISCARD_RP("Ethernet type (%d) != IP", ntohs(eth_hdr->ether_type));
+
+ /* If Ethernet destination is not broadcast (ff:ff:ff:ff:ff:ff)
+ * Check if it matches the source HW address used (DHCP-Client-Hardware-Address = 267)
+ */
+ if ( (memcmp(ð_bcast, ð_hdr->ether_dst, ETH_ADDR_LEN) != 0) &&
+ (vp = fr_pair_find_by_num(request->vps, 267, DHCP_MAGIC_VENDOR, TAG_ANY)) &&
+ (vp->length == sizeof(vp->vp_ether)) &&
+ (memcmp(vp->vp_ether, ð_hdr->ether_dst, ETH_ADDR_LEN) != 0) ) {
+ /* No match. */
+ char eth_dest[17+1];
+ char eth_req_src[17+1];
+ DISCARD_RP("Ethernet destination (%s) is not broadcast and doesn't match request source (%s)",
+ ether_addr_print(eth_hdr->ether_dst, eth_dest),
+ ether_addr_print(vp->vp_ether, eth_req_src));
+ }
+
+ /*
+ * Ethernet is OK. Now look at IP.
+ */
+ ip_hdr = (struct ip_header *)(raw_packet + ETH_HDR_SIZE);
+
+ /* b. Check IPv4 layer data (L3) */
+ if (ip_hdr->ip_p != IPPROTO_UDP) DISCARD_RP("IP protocol (%d) != UDP", ip_hdr->ip_p);
+
+ /*
+ * note: checking the destination IP address is not
+ * useful (it would be the offered IP address - which we
+ * don't know beforehand, or the broadcast address).
+ */
+
+ /*
+ * Now check UDP.
+ */
+ udp_hdr = (udp_header_t *)(raw_packet + ETH_HDR_SIZE + IP_HDR_SIZE);
+
+ /* c. Check UDP layer data (L4) */
+ udp_src_port = ntohs(udp_hdr->src);
+ udp_dst_port = ntohs(udp_hdr->dst);
+
+ /*
+ * A DHCP server will always respond to port 68 (to a
+ * client) or 67 (to a relay). Just check that both
+ * ports are 67 or 68.
+ */
+ if (udp_src_port != 67 && udp_src_port != 68) DISCARD_RP("UDP src port (%d) != DHCP (67 or 68)", udp_src_port);
+ if (udp_dst_port != 67 && udp_dst_port != 68) DISCARD_RP("UDP dst port (%d) != DHCP (67 or 68)", udp_dst_port);
+
+ /* d. Check DHCP layer data */
+ dhcp_data_len = data_len - data_offset;
+
+ if (dhcp_data_len < MIN_PACKET_SIZE) DISCARD_RP("DHCP packet is too small (%d < %d)", dhcp_data_len, MIN_PACKET_SIZE);
+ if (dhcp_data_len > MAX_PACKET_SIZE) DISCARD_RP("DHCP packet is too large (%d > %d)", dhcp_data_len, MAX_PACKET_SIZE);
+
+ dhcp_hdr = (dhcp_packet_t *)(raw_packet + ETH_HDR_SIZE + IP_HDR_SIZE + UDP_HDR_SIZE);
+
+ if (dhcp_hdr->htype != 1) DISCARD_RP("DHCP hardware type (%d) != Ethernet (1)", dhcp_hdr->htype);
+ if (dhcp_hdr->hlen != 6) DISCARD_RP("DHCP hardware address length (%d) != 6", dhcp_hdr->hlen);
+
+ magic = ntohl(dhcp_hdr->option_format);
+
+ if (magic != DHCP_OPTION_MAGIC_NUMBER) DISCARD_RP("DHCP magic cookie (0x%04x) != DHCP (0x%04x)", magic, DHCP_OPTION_MAGIC_NUMBER);
+
+ /*
+ * Reply transaction id must match value from request.
+ */
+ xid = ntohl(dhcp_hdr->xid);
+ if (xid != (uint32_t)request->id) DISCARD_RP("DHCP transaction ID (0x%04x) != xid from request (0x%04x)", xid, request->id)
+
+ /* all checks ok! this is a DHCP reply we're interested in. */
+ packet->data_len = dhcp_data_len;
+ packet->data = talloc_memdup(packet, raw_packet + data_offset, dhcp_data_len);
+ TALLOC_FREE(raw_packet);
+ packet->id = xid;
+
+ code = dhcp_get_option((dhcp_packet_t *) packet->data,
+ packet->data_len, PW_DHCP_MESSAGE_TYPE);
+ if (!code) {
+ fr_strerror_printf("No message-type option was found in the packet");
+ rad_free(&packet);
+ return NULL;
+ }
+
+ if ((code[1] < 1) || (code[2] == 0) || (code[2] > 8)) {
+ fr_strerror_printf("Unknown value for message-type option");
+ rad_free(&packet);
+ return NULL;
+ }
+
+ packet->code = code[2] | PW_DHCP_OFFSET;
+
+ /*
+ * Create a unique vector from the MAC address and the
+ * DHCP opcode. This is a hack for the RADIUS
+ * infrastructure in the rest of the server.
+ *
+ * Note: packet->data[2] == 6, which is smaller than
+ * sizeof(packet->vector)
+ *
+ * FIXME: Look for client-identifier in packet,
+ * and use that, too?
+ */
+ memset(packet->vector, 0, sizeof(packet->vector));
+ memcpy(packet->vector, packet->data + 28, packet->data[2]);
+ packet->vector[packet->data[2]] = packet->code & 0xff;
+
+ packet->src_port = udp_src_port;
+ packet->dst_port = udp_dst_port;
+
+ packet->src_ipaddr.af = AF_INET;
+ packet->src_ipaddr.ipaddr.ip4addr.s_addr = ip_hdr->ip_src.s_addr;
+ packet->dst_ipaddr.af = AF_INET;
+ packet->dst_ipaddr.ipaddr.ip4addr.s_addr = ip_hdr->ip_dst.s_addr;
+
+ if (fr_debug_lvl > 1) {
+ char type_buf[64];
+ char const *name = type_buf;
+ char src_ip_buf[256], dst_ip_buf[256];
+
+ if ((packet->code >= PW_DHCP_DISCOVER) &&
+ (packet->code < (1024 + DHCP_MAX_MESSAGE_TYPE))) {
+ name = dhcp_message_types[packet->code - PW_DHCP_OFFSET];
+ } else {
+ snprintf(type_buf, sizeof(type_buf), "%d", packet->code - PW_DHCP_OFFSET);
+ }
+
+ DEBUG("Received %s of Id %08x from %s:%d to %s:%d\n",
+ name, (unsigned int) packet->id,
+ inet_ntop(packet->src_ipaddr.af, &packet->src_ipaddr.ipaddr, src_ip_buf, sizeof(src_ip_buf)),
+ packet->src_port,
+ inet_ntop(packet->dst_ipaddr.af, &packet->dst_ipaddr.ipaddr, dst_ip_buf, sizeof(dst_ip_buf)),
+ packet->dst_port);
+ }
+
+ return packet;
+}
+#endif
projects / freeradius.git / blobdiff