add function to pretty-print DHCPv6 packets as hex

diff --git a/src/protocols/dhcpv6/base.c b/src/protocols/dhcpv6/base.c
index 4958addcae34d5deed724ded7941ee2738c11ab1..3f77d17f032a5a6e91d08a94cd86cee46d10eb5c 100644 (file)
--- a/src/protocols/dhcpv6/base.c
+++ b/src/protocols/dhcpv6/base.c
@@ -878,6 +878,106 @@ ssize_t   fr_dhcpv6_encode(fr_dbuff_t *dbuff, uint8_t const *original, size_t leng
        return fr_dbuff_used(dbuff);
 }
 
+
+static char const tabs[] = "\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
+
+static void print_hex_data(FILE *fp, uint8_t const *ptr, int attrlen, int depth)
+{
+       int i;
+
+       for (i = 0; i < attrlen; i++) {
+               if ((i > 0) && ((i & 0x0f) == 0x00))
+                       fprintf(fp, "%.*s", depth, tabs);
+               fprintf(fp, "%02x ", ptr[i]);
+               if ((i & 0x0f) == 0x0f) fprintf(fp, "\n");
+       }
+       if ((i & 0x0f) != 0) fprintf(fp, "\n");
+}
+
+static void dhcpv6_print_hex(FILE *fp, uint8_t const *packet, size_t packet_len, int depth)
+{
+       uint8_t const *option, *end = packet + packet_len;
+
+       if (packet_len < 4) {
+               fprintf(fp, "%.*s", depth, tabs);
+               fprintf(fp, "???:\t");
+               print_hex_data(fp, packet, packet_len, depth + 1);
+               return;
+       }
+
+       fprintf(fp, "%.*s", depth, tabs);
+       if ((packet[0] > 0) && (packet[0] < FR_DHCPV6_MAX_CODE)) {
+               fprintf(fp, "packet: %s\n", fr_dhcpv6_packet_types[packet[0]]);
+       } else {
+               fprintf(fp, "packet: %02x\n", packet[0]);
+       }
+
+       if ((packet[0] == FR_PACKET_TYPE_VALUE_RELAY_FORWARD) ||
+           (packet[0] == FR_PACKET_TYPE_VALUE_RELAY_REPLY)) {
+               if (packet_len < 34) {
+                       fprintf(fp, "%.*s", depth, tabs);
+                       fprintf(fp, "???:\t");
+                       print_hex_data(fp, packet + 1, packet_len - 1, depth + 1);
+                       return;
+               }
+
+               fprintf(fp, "%.*s", depth, tabs);
+               fprintf(fp, "hops: %02x\n", packet[1]);
+               fprintf(fp, "%.*s", depth, tabs);
+               fprintf(fp, "relay link address: ");
+               print_hex_data(fp, packet + 2, 16, depth + 1);
+
+               fprintf(fp, "%.*s", depth, tabs);
+               fprintf(fp, "peer address:       ");
+               print_hex_data(fp, packet + 18, 16, depth + 1);
+               option = packet + 34;
+       } else {
+               fprintf(fp, "%.*s", depth, tabs);
+               fprintf(fp, "transaction id: ");
+               print_hex_data(fp, packet + 1, 3, depth + 1);
+               option = packet + 4;
+       }
+
+       fprintf(fp, "%.*s", depth, tabs);
+       fprintf(fp, "options\n");
+       while (option < end) {
+               uint16_t length;
+
+               if ((end - option) < 4) {
+                       fprintf(fp, "%.*s", depth + 1, tabs);
+                       fprintf(fp, "???:\t");
+                       print_hex_data(fp, option, end - option, depth + 2);
+                       break;
+               }
+
+               length = fr_net_to_uint16(option + 2);
+               fprintf(fp, "%.*s", depth + 1, tabs);
+               fprintf(fp, "%04x %04x\t", fr_net_to_uint16(option), length);
+
+               if ((option + 4 + length) > end) {
+                       print_hex_data(fp, option + 4, end - (option + 4), depth + 2);
+                       break;
+               }
+
+               print_hex_data(fp, option + 4, length, depth + 3);
+               if ((option[0] == 0) && (option[1] == attr_relay_message->attr)) {
+                       dhcpv6_print_hex(fp, option + 4, length, depth + 2);
+               }
+
+               option += 4 + length;
+       }
+
+       fprintf(fp, "\n");
+}
+
+/** Print a raw DHCP packet as hex.
+ *
+ */
+void fr_dhcpv6_print_hex(FILE *fp, uint8_t const *packet, size_t packet_len)
+{
+       dhcpv6_print_hex(fp, packet, packet_len, 0);
+}
+
 int fr_dhcpv6_global_init(void)
 {
        fr_dict_attr_t const *child;

diff --git a/src/protocols/dhcpv6/dhcpv6.h b/src/protocols/dhcpv6/dhcpv6.h
index c3db059a83b58af8d68c3fe6c53b29556de0c21d..33cba5f11b00df3f1f8e25f7d4176779c8af7f55 100644 (file)
--- a/src/protocols/dhcpv6/dhcpv6.h
+++ b/src/protocols/dhcpv6/dhcpv6.h
@@ -157,6 +157,8 @@ ssize_t             fr_dhcpv6_encode(fr_dbuff_t *dbuff, uint8_t const *original, size_t len
 ssize_t                fr_dhcpv6_decode(TALLOC_CTX *ctx, uint8_t const *packet, size_t packet_len,
                                 fr_cursor_t *cursor);
 
+void           fr_dhcpv6_print_hex(FILE *fp, uint8_t const *packet, size_t packet_len);
+
 int            fr_dhcpv6_global_init(void);
 
 void           fr_dhcpv6_global_free(void);