diff -up dhcp-4.3.3/client/dhclient.c.duid_uuid dhcp-4.3.3/client/dhclient.c --- dhcp-4.3.3/client/dhclient.c.duid_uuid 2015-12-14 12:10:54.694082625 +0100 +++ dhcp-4.3.3/client/dhclient.c 2015-12-14 12:13:19.538018362 +0100 @@ -3328,6 +3328,59 @@ write_options(struct client_state *clien } } +int unhexchar(char c) { + + if (c >= '0' && c <= '9') + return c - '0'; + + if (c >= 'a' && c <= 'f') + return c - 'a' + 10; + + if (c >= 'A' && c <= 'F') + return c - 'A' + 10; + + return -1; +} + +isc_result_t +read_uuid(u_int8_t* uuid) { + const char *id_fname = "/etc/machine-id"; + char id[32]; + size_t nread; + FILE * file = fopen( id_fname , "r"); + if (!file) { + log_debug("Cannot open %s", id_fname); + return ISC_R_IOERROR; + } + nread = fread(id, 1, sizeof id, file); + fclose(file); + + if (nread < 32) { + log_debug("Not enough data in %s", id_fname); + return ISC_R_IOERROR; + } + + for (int j = 0; j < 16; j++) { + int a, b; + + a = unhexchar(id[j*2]); + b = unhexchar(id[j*2+1]); + + if (a < 0 || b < 0) { + log_debug("Wrong data in %s", id_fname); + return ISC_R_IOERROR; + } + uuid[j] = a << 4 | b; + } + + /* Set UUID version to 4 --- truly random generation */ + uuid[6] = (uuid[6] & 0x0F) | 0x40; + /* Set the UUID variant to DCE */ + uuid[8] = (uuid[8] & 0x3F) | 0x80; + + return ISC_R_SUCCESS; +} + /* * The "best" default DUID, since we cannot predict any information * about the system (such as whether or not the hardware addresses are @@ -3348,6 +3401,7 @@ form_duid(struct data_string *duid, cons struct interface_info *ip; int len; char *str; + u_int8_t uuid[16]; /* For now, just use the first interface on the list. */ ip = interfaces; @@ -3368,9 +3422,16 @@ form_duid(struct data_string *duid, cons (ip->hw_address.hlen > sizeof(ip->hw_address.hbuf))) log_fatal("Impossible hardware address length at %s:%d.", MDL); - if (duid_type == 0) - duid_type = stateless ? DUID_LL : DUID_LLT; - + if (duid_type == 0) { + if (read_uuid(uuid) == ISC_R_SUCCESS) + duid_type = DUID_UUID; + else + duid_type = stateless ? DUID_LL : DUID_LLT; + } + + if (duid_type == DUID_UUID) + len = 2 + sizeof (uuid); + else { /* * 2 bytes for the 'duid type' field. * 2 bytes for the 'htype' field. @@ -3381,13 +3442,18 @@ form_duid(struct data_string *duid, cons len = 4 + (ip->hw_address.hlen - 1); if (duid_type == DUID_LLT) len += 4; + } if (!buffer_allocate(&duid->buffer, len, MDL)) log_fatal("no memory for default DUID!"); duid->data = duid->buffer->data; duid->len = len; + if (duid_type == DUID_UUID) { + putUShort(duid->buffer->data, DUID_UUID); + memcpy(duid->buffer->data + 2, uuid, sizeof(uuid)); + } /* Basic Link Local Address type of DUID. */ - if (duid_type == DUID_LLT) { + else if (duid_type == DUID_LLT) { putUShort(duid->buffer->data, DUID_LLT); putUShort(duid->buffer->data + 2, ip->hw_address.hbuf[0]); putULong(duid->buffer->data + 4, cur_time - DUID_TIME_EPOCH); diff -up dhcp-4.3.3/includes/dhcp6.h.duid_uuid dhcp-4.3.3/includes/dhcp6.h --- dhcp-4.3.3/includes/dhcp6.h.duid_uuid 2015-08-26 21:13:14.000000000 +0200 +++ dhcp-4.3.3/includes/dhcp6.h 2015-12-14 12:12:33.258038895 +0100 @@ -119,6 +119,8 @@ extern const int dhcpv6_type_name_max; #define DUID_LLT 1 #define DUID_EN 2 #define DUID_LL 3 +/* RFC6355 */ +#define DUID_UUID 4 /* Offsets into IA_*'s where Option spaces commence. */ #define IA_NA_OFFSET 12 /* IAID, T1, T2, all 4 octets each */