Both DHCPv4 and DHCPv6 has the capability to pass the hostname to
clients, the DHCPv4 uses option 12 (hostname) while the DHCPv6 uses option 39
(client fqdn), for some virt deployments like kubevirt is expected to
have the VirtualMachine name as the guest hostname.
This change add the -H --hostname to configure the DHCPv4 and DHCPv6
options to will send hostname to clients.
Signed-off-by: Enrique Llorente <ellorent(a)redhat.com>
---
conf.c | 13 ++++++++++---
dhcp.c | 8 +++++++-
dhcpv6.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
passt.h | 2 ++
test/lib/setup | 10 +++++-----
test/passt.mbuto | 1 +
test/passt/dhcp | 11 ++++++++++-
7 files changed, 78 insertions(+), 11 deletions(-)
diff --git a/conf.c b/conf.c
index 14411b4..ddb585c 100644
--- a/conf.c
+++ b/conf.c
@@ -847,7 +847,8 @@ static void usage(const char *name, FILE *f, int status)
" --freebind Bind to any address for forwarding\n"
" --no-map-gw Don't map gateway address to host\n"
" -4, --ipv4-only Enable IPv4 operation only\n"
- " -6, --ipv6-only Enable IPv6 operation only\n");
+ " -6, --ipv6-only Enable IPv6 operation only\n"
+ " -H, --hostname NAME Hostname to configure client with\n");
if (strstr(name, "pasta"))
goto pasta_opts;
@@ -1303,6 +1304,7 @@ void conf(struct ctx *c, int argc, char **argv)
{"map-guest-addr", required_argument, NULL, 22 },
{"host-lo-to-ns-lo", no_argument, NULL, 23 },
{"dns-host", required_argument, NULL, 24 },
+ {"hostname", required_argument, NULL, 'H' },
{ 0 },
};
const char *logname = (c->mode == MODE_PASTA) ? "pasta" :
"passt";
@@ -1325,9 +1327,9 @@ void conf(struct ctx *c, int argc, char **argv)
if (c->mode == MODE_PASTA) {
c->no_dhcp_dns = c->no_dhcp_dns_search = 1;
fwd_default = FWD_AUTO;
- optstring = "+dqfel:hF:I:p:P:m:a:n:M:g:i:o:D:S:46t:u:T:U:";
+ optstring = "+dqfel:hF:I:p:P:m:a:n:M:g:i:o:D:S:46t:u:T:U:H:";
} else {
- optstring = "+dqfel:hs:F:p:P:m:a:n:M:g:i:o:D:S:461t:u:";
+ optstring = "+dqfel:hs:F:p:P:m:a:n:M:g:i:o:D:S:461t:u:H:";
}
c->tcp.fwd_in.mode = c->tcp.fwd_out.mode = FWD_UNSET;
@@ -1680,6 +1682,11 @@ void conf(struct ctx *c, int argc, char **argv)
c->one_off = true;
break;
+ case 'H':
+ ret = snprintf(c->hostname.n, sizeof(c->hostname.n), "%s", optarg);
+ if (ret <= 0 || ret >= (int)sizeof(c->hostname.n))
+ die("Invalid hostname: %s", optarg);
+ break;
case 't':
case 'u':
case 'T':
diff --git a/dhcp.c b/dhcp.c
index a06f143..ec7e78a 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -275,7 +275,7 @@ static void opt_set_dns_search(const struct ctx *c, size_t max_len)
*/
int dhcp(const struct ctx *c, const struct pool *p)
{
- size_t mlen, dlen, offset = 0, opt_len, opt_off = 0;
+ size_t mlen, dlen, offset = 0, opt_len, opt_off = 0, hostname_len;
char macstr[ETH_ADDRSTRLEN];
const struct ethhdr *eh;
const struct iphdr *iph;
@@ -375,6 +375,12 @@ int dhcp(const struct ctx *c, const struct pool *p)
opts[6].slen += sizeof(uint32_t);
}
+ hostname_len = strlen(c->hostname.n);
+ if ( hostname_len > 0 ) {
+ opts[12].slen = hostname_len;
+ memcpy(opts[12].s, &c->hostname.n, hostname_len);
+ }
+
if (!c->no_dhcp_dns_search)
opt_set_dns_search(c, sizeof(m->o));
diff --git a/dhcpv6.c b/dhcpv6.c
index 14a5c7e..190dc0e 100644
--- a/dhcpv6.c
+++ b/dhcpv6.c
@@ -48,6 +48,7 @@ struct opt_hdr {
# define STATUS_NOTONLINK htons_constant(4)
# define OPT_DNS_SERVERS htons_constant(23)
# define OPT_DNS_SEARCH htons_constant(24)
+# define OPT_CLIENT_FQDN htons_constant(39)
#define STR_NOTONLINK "Prefix not appropriate for link."
uint16_t l;
@@ -163,6 +164,18 @@ struct opt_dns_search {
char list[MAXDNSRCH * NS_MAXDNAME];
} __attribute__((packed));
+/**
+ * struct opt_client_fqdn - Client FQDN option (RFC 4704)
+ * @hdr: Option header
+ * @flags: Flags as stated at RFC 4704
+ * @hostname: Client fqdn
+ */
+struct opt_client_fqdn{
+ struct opt_hdr hdr;
+ uint8_t flags;
+ uint8_t hostname[NS_MAXDNAME];
+} __attribute__((packed));
+
/**
* struct msg_hdr - DHCPv6 client/server message header
* @type: DHCP message type
@@ -191,6 +204,7 @@ struct msg_hdr {
* @ia_na: Non-temporary Address option
* @ia_addr: Address for IA_NA
* @client_id: Client Identifier, variable length
+ * @client_fqdn: Client FQDN, variable length
* @dns_servers: DNS Recursive Name Server, here just for storage size
* @dns_search: Domain Search List, here just for storage size
*/
@@ -203,10 +217,10 @@ static struct resp_t {
struct opt_client_id client_id;
struct opt_dns_servers dns_servers;
struct opt_dns_search dns_search;
+ struct opt_client_fqdn client_fqdn;
} __attribute__((__packed__)) resp = {
{ 0 },
SERVER_ID,
-
{ { OPT_IA_NA, OPT_SIZE_CONV(sizeof(struct opt_ia_na) +
sizeof(struct opt_ia_addr) -
sizeof(struct opt_hdr)) },
@@ -228,6 +242,10 @@ static struct resp_t {
{ { OPT_DNS_SEARCH, 0, },
{ 0 },
},
+
+ { { OPT_CLIENT_FQDN, 0, },
+ (uint8_t)~0U, { 0 },
+ },
};
static const struct opt_status_code sc_not_on_link = {
@@ -416,6 +434,29 @@ search:
return offset;
}
+/**
+ * dhcpv6_client_fqdn_fill() - Fill in client FQDN option
+ * @c: Execution context
+ * @buf: Response message buffer where options will be appended
+ * @offset: Offset in message buffer for new options
+ *
+ * Return: updated length of response message buffer.
+ */
+static size_t dhcpv6_client_fqdn_fill(const struct ctx *c, char *buf, int offset)
+{
+ uint16_t hostname_len = strlen(c->hostname.n);
+ if (hostname_len > 0) {
+ struct opt_client_fqdn *o = (struct opt_client_fqdn*)(buf + offset);
+ o->hdr.t = OPT_CLIENT_FQDN;
+ o->hdr.l = htons(hostname_len+2);
+ o->flags = 0x00;
+ *o->hostname = hostname_len;
+ memcpy(o->hostname+1, c->hostname.n, hostname_len);
+ offset += sizeof(struct opt_hdr) + hostname_len+2;
+ }
+ return offset;
+}
+
/**
* dhcpv6() - Check if this is a DHCPv6 message, reply as needed
* @c: Execution context
@@ -549,6 +590,7 @@ int dhcpv6(struct ctx *c, const struct pool *p,
n = offsetof(struct resp_t, client_id) +
sizeof(struct opt_hdr) + ntohs(client_id->l);
n = dhcpv6_dns_fill(c, (char *)&resp, n);
+ n = dhcpv6_client_fqdn_fill(c, (char*)&resp, n);
resp.hdr.xid = mh->xid;
diff --git a/passt.h b/passt.h
index 72c7f72..d9864e6 100644
--- a/passt.h
+++ b/passt.h
@@ -205,6 +205,7 @@ struct ip6_ctx {
* @ifi4: Index of template interface for IPv4, 0 if IPv4 disabled
* @ip: IPv4 configuration
* @dns_search: DNS search list
+ * @hostname: Client hostname
* @ifi6: Index of template interface for IPv6, 0 if IPv6 disabled
* @ip6: IPv6 configuration
* @pasta_ifn: Name of namespace interface for pasta
@@ -262,6 +263,7 @@ struct ctx {
struct ip4_ctx ip4;
struct fqdn dns_search[MAXDNSRCH];
+ struct fqdn hostname;
unsigned int ifi6;
struct ip6_ctx ip6;
diff --git a/test/lib/setup b/test/lib/setup
index 5338393..9c7aac9 100755
--- a/test/lib/setup
+++ b/test/lib/setup
@@ -49,7 +49,7 @@ setup_passt() {
context_run passt "make clean"
context_run passt "make valgrind"
- context_run_bg passt "valgrind --max-stackframe=$((4 * 1024 * 1024))
--trace-children=yes --vgdb=no --error-exitcode=1 --suppressions=test/valgrind.supp
./passt ${__opts} -s ${STATESETUP}/passt.socket -f -t 10001 -u 10001 -P
${STATESETUP}/passt.pid"
+ context_run_bg passt "valgrind --max-stackframe=$((4 * 1024 * 1024))
--trace-children=yes --vgdb=no --error-exitcode=1 --suppressions=test/valgrind.supp
./passt ${__opts} -s ${STATESETUP}/passt.socket -f -t 10001 -u 10001 -H passt1 -P
${STATESETUP}/passt.pid"
# pidfile isn't created until passt is listening
wait_for [ -f "${STATESETUP}/passt.pid" ]
@@ -146,11 +146,11 @@ setup_passt_in_ns() {
if [ ${VALGRIND} -eq 1 ]; then
context_run passt "make clean"
context_run passt "make valgrind"
- context_run_bg passt "valgrind --max-stackframe=$((4 * 1024 * 1024))
--trace-children=yes --vgdb=no --error-exitcode=1 --suppressions=test/valgrind.supp
./passt -f ${__opts} -s ${STATESETUP}/passt.socket -t 10001,10011,10021,10031 -u
10001,10011,10021,10031 -P ${STATESETUP}/passt.pid --map-host-loopback ${__map_ns4}
--map-host-loopback ${__map_ns6}"
+ context_run_bg passt "valgrind --max-stackframe=$((4 * 1024 * 1024))
--trace-children=yes --vgdb=no --error-exitcode=1 --suppressions=test/valgrind.supp
./passt -f ${__opts} -s ${STATESETUP}/passt.socket -H passt1 -t 10001,10011,10021,10031 -u
10001,10011,10021,10031 -P ${STATESETUP}/passt.pid --map-host-loopback ${__map_ns4}
--map-host-loopback ${__map_ns6}"
else
context_run passt "make clean"
context_run passt "make"
- context_run_bg passt "./passt -f ${__opts} -s ${STATESETUP}/passt.socket -t
10001,10011,10021,10031 -u 10001,10011,10021,10031 -P ${STATESETUP}/passt.pid
--map-host-loopback ${__map_ns4} --map-host-loopback ${__map_ns6}"
+ context_run_bg passt "./passt -f ${__opts} -s ${STATESETUP}/passt.socket -H passt1
-t 10001,10011,10021,10031 -u 10001,10011,10021,10031 -P ${STATESETUP}/passt.pid
--map-host-loopback ${__map_ns4} --map-host-loopback ${__map_ns6}"
fi
wait_for [ -f "${STATESETUP}/passt.pid" ]
@@ -215,7 +215,7 @@ setup_two_guests() {
[ ${DEBUG} -eq 1 ] && __opts="${__opts} -d"
[ ${TRACE} -eq 1 ] && __opts="${__opts} --trace"
- context_run_bg passt_1 "./passt -s ${STATESETUP}/passt_1.socket -P
${STATESETUP}/passt_1.pid -f ${__opts} -t 10001 -u 10001"
+ context_run_bg passt_1 "./passt -s ${STATESETUP}/passt_1.socket -P
${STATESETUP}/passt_1.pid -f ${__opts} -H passt1 -t 10001 -u 10001"
wait_for [ -f "${STATESETUP}/passt_1.pid" ]
__opts=
@@ -223,7 +223,7 @@ setup_two_guests() {
[ ${DEBUG} -eq 1 ] && __opts="${__opts} -d"
[ ${TRACE} -eq 1 ] && __opts="${__opts} --trace"
- context_run_bg passt_2 "./passt -s ${STATESETUP}/passt_2.socket -P
${STATESETUP}/passt_2.pid -f ${__opts} -t 10004 -u 10004"
+ context_run_bg passt_2 "./passt -s ${STATESETUP}/passt_2.socket -P
${STATESETUP}/passt_2.pid -f ${__opts} --hostname passt2 -t 10004 -u 10004"
wait_for [ -f "${STATESETUP}/passt_2.pid" ]
GUEST_1_CID=94557
diff --git a/test/passt.mbuto b/test/passt.mbuto
index 138d365..bcd9041 100755
--- a/test/passt.mbuto
+++ b/test/passt.mbuto
@@ -55,6 +55,7 @@ set >> \$LOG
[ -n "\${new_dhcp6_name_servers}" ] && for d in
\${new_dhcp6_name_servers}; do echo "nameserver \${d}%\${interface}" >>
/etc/resolv.conf; done
[ -n "\${new_dhcp6_domain_search}" ] && (printf "search"; for
d in \${new_dhcp6_domain_search}; do printf " %s" "\${d}"; done;
printf "\n") >> /etc/resolv.conf
[ -n "\${new_host_name}" ] && hostname
"\${new_host_name}"
+[ -n "\${new_fqdn_hostname}" ] && hostname
"\${new_fqdn_hostname}"
exit 0
EOF
chmod 755 /sbin/dhclient-script
diff --git a/test/passt/dhcp b/test/passt/dhcp
index 9925ab9..36535f2 100644
--- a/test/passt/dhcp
+++ b/test/passt/dhcp
@@ -11,7 +11,7 @@
# Copyright (c) 2021 Red Hat GmbH
# Author: Stefano Brivio <sbrivio(a)redhat.com>
-gtools ip jq dhclient sed tr
+gtools ip jq dhclient sed tr hostname
htools ip jq sed tr head
test Interface name
@@ -47,7 +47,12 @@ gout SEARCH sed 's/\. / /g' /etc/resolv.conf | sed
's/\.$//g' | sed -n 's/^searc
hout HOST_SEARCH sed 's/\. / /g' /etc/resolv.conf | sed 's/\.$//g' |
sed -n 's/^search \(.*\)/\1/p' | tr ' \n' ',' | sed
's/,$//;s/$/\n/'
check [ "__SEARCH__" = "__HOST_SEARCH__" ]
+test DHCP: Hostname
+gout HOSTNAME hostname
+check [ "__HOSTNAME__" = "passt1" ]
+
test DHCPv6: address
+guest hostname none
guest /sbin/dhclient -6 __IFNAME__
# Wait for DAD to complete
guest while ip -j -6 addr show tentative | jq -e '.[].addr_info'; do sleep 0.1;
done
@@ -70,3 +75,7 @@ test DHCPv6: search list
gout SEARCH6 sed 's/\. / /g' /etc/resolv.conf | sed 's/\.$//g' | sed
-n 's/^search \(.*\)/\1/p' | tr ' \n' ',' | sed
's/,$//;s/$/\n/'
hout HOST_SEARCH6 sed 's/\. / /g' /etc/resolv.conf | sed 's/\.$//g' |
sed -n 's/^search \(.*\)/\1/p' | tr ' \n' ',' | sed
's/,$//;s/$/\n/'
check [ "__SEARCH6__" = "__HOST_SEARCH6__" ]
+
+test DHCPv6: Hostname
+gout HOSTNAME hostname
+check [ "__HOSTNAME__" = "passt1" ]
--
2.47.0