As a part of the multiple address support feature, we add a new
algorithm for DHCP/DHCPv6/NDP address selection and refactor the
conf_print() function accordingly.
The fwd_first_usable_addr() and fwd_select_addr() functions now take
a context pointer and address family parameter to work with the
unified address array using for_each_addr().
Signed-off-by: Jon Maloy
---
conf.c | 60 +++++++++++++++++++++++++----------------
dhcp.c | 17 +++++++++---
dhcp.h | 2 +-
dhcpv6.c | 17 ++++++++++--
fwd.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
fwd.h | 6 +++++
ndp.c | 15 ++++++++---
ndp.h | 4 +--
passt.h | 3 +++
9 files changed, 171 insertions(+), 35 deletions(-)
diff --git a/conf.c b/conf.c
index 6892cea..4c53d33 100644
--- a/conf.c
+++ b/conf.c
@@ -46,6 +46,7 @@
#include "lineread.h"
#include "isolation.h"
#include "log.h"
+#include "fwd.h"
#include "vhost_user.h"
#define NETNS_RUN_DIR "/run/netns"
@@ -1099,10 +1100,12 @@ enum passt_modes conf_mode(int argc, char *argv[])
static void conf_print(const struct ctx *c)
{
char buf4[INET_ADDRSTRLEN], buf6[INET6_ADDRSTRLEN];
- char bufmac[ETH_ADDRSTRLEN], ifn[IFNAMSIZ];
+ char bufmac[ETH_ADDRSTRLEN];
int i;
if (c->ifi4 > 0 || c->ifi6 > 0) {
+ char ifn[IFNAMSIZ];
+
info("Template interface: %s%s%s%s%s",
c->ifi4 > 0 ? if_indextoname(c->ifi4, ifn) : "",
c->ifi4 > 0 ? " (IPv4)" : "",
@@ -1144,20 +1147,22 @@ static void conf_print(const struct ctx *c)
buf4, sizeof(buf4)));
if (!c->no_dhcp) {
- struct inany_addr_entry *e = first_v4(c);
- uint32_t mask;
-
- mask = IN4_MASK(e->prefix_len);
-
- info("DHCP:");
- info(" assign: %s",
- inet_ntop(AF_INET, inany_v4(&e->addr),
- buf4, sizeof(buf4)));
- info(" mask: %s",
- inet_ntop(AF_INET, &mask, buf4, sizeof(buf4)));
- info(" router: %s",
- inet_ntop(AF_INET, &c->ip4.guest_gw,
- buf4, sizeof(buf4)));
+ const struct inany_addr_entry *e;
+
+ e = fwd_first_usable_addr(c, AF_INET,
+ INANY_ADDR_OBSERVED);
+ if (e) {
+ uint32_t mask = IN4_MASK(e->prefix_len);
+
+ info("DHCP:");
+ info(" assign: %s",
+ inany_ntop(&e->addr, buf4, sizeof(buf4)));
+ info(" mask: %s",
+ inet_ntop(AF_INET, &mask, buf4, sizeof(buf4)));
+ info(" router: %s",
+ inet_ntop(AF_INET, &c->ip4.guest_gw,
+ buf4, sizeof(buf4)));
+ }
}
for (i = 0; !IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns[i]); i++) {
@@ -1189,14 +1194,23 @@ static void conf_print(const struct ctx *c)
else
goto dns6;
- info(" assign: %s",
- inet_ntop(AF_INET6, &first_v6(c)->addr.a6,
- buf6, sizeof(buf6)));
- info(" router: %s",
- inet_ntop(AF_INET6, &c->ip6.guest_gw, buf6, sizeof(buf6)));
- info(" our link-local: %s",
- inet_ntop(AF_INET6, &c->ip6.our_tap_ll,
- buf6, sizeof(buf6)));
+ {
+ const struct inany_addr_entry *e;
+
+ e = fwd_first_usable_addr(c, AF_INET6,
+ INANY_ADDR_OBSERVED |
+ INANY_ADDR_LINKLOCAL);
+ if (e) {
+ info(" assign: %s",
+ inany_ntop(&e->addr, buf6, sizeof(buf6)));
+ info(" router: %s",
+ inet_ntop(AF_INET6, &c->ip6.guest_gw,
+ buf6, sizeof(buf6)));
+ info(" our link-local: %s",
+ inet_ntop(AF_INET6, &c->ip6.our_tap_ll,
+ buf6, sizeof(buf6)));
+ }
+ }
dns6:
for (i = 0; !IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns[i]); i++) {
diff --git a/dhcp.c b/dhcp.c
index 933a8cf..31ea4f1 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -31,6 +31,7 @@
#include "passt.h"
#include "tap.h"
#include "log.h"
+#include "fwd.h"
#include "dhcp.h"
/**
@@ -300,8 +301,9 @@ static void opt_set_dns_search(const struct ctx *c, size_t max_len)
*
* Return: 0 if it's not a DHCP message, 1 if handled, -1 on failure
*/
-int dhcp(const struct ctx *c, struct iov_tail *data)
+int dhcp(struct ctx *c, struct iov_tail *data)
{
+ union inany_addr yiaddr = { 0 };
char macstr[ETH_ADDRSTRLEN];
size_t mlen, dlen, opt_len;
struct in_addr mask, dst;
@@ -314,7 +316,7 @@ int dhcp(const struct ctx *c, struct iov_tail *data)
struct msg m_storage;
struct msg const *m;
struct msg reply;
- unsigned int i;
+ int i;
eh = IOV_REMOVE_HEADER(data, eh_storage);
iph = IOV_PEEK_HEADER(data, iph_storage);
@@ -344,6 +346,15 @@ int dhcp(const struct ctx *c, struct iov_tail *data)
m->op != BOOTREQUEST)
return -1;
+ /* Select address to offer */
+ {
+ const struct inany_addr_entry *e;
+
+ e = fwd_select_addr(c, AF_INET, INANY_ADDR_DHCP,
+ INANY_ADDR_OBSERVED);
+ if (e)
+ yiaddr = e->addr;
+ }
reply.op = BOOTREPLY;
reply.htype = m->htype;
reply.hlen = m->hlen;
@@ -352,7 +363,7 @@ int dhcp(const struct ctx *c, struct iov_tail *data)
reply.secs = 0;
reply.flags = m->flags;
reply.ciaddr = m->ciaddr;
- reply.yiaddr = *inany_v4(&first_v4(c)->addr);
+ reply.yiaddr = *inany_v4(&yiaddr);
reply.siaddr = 0;
reply.giaddr = m->giaddr;
memcpy(&reply.chaddr, m->chaddr, sizeof(reply.chaddr));
diff --git a/dhcp.h b/dhcp.h
index cd50c99..7326c7d 100644
--- a/dhcp.h
+++ b/dhcp.h
@@ -6,7 +6,7 @@
#ifndef DHCP_H
#define DHCP_H
-int dhcp(const struct ctx *c, struct iov_tail *data);
+int dhcp(struct ctx *c, struct iov_tail *data);
void dhcp_init(void);
#endif /* DHCP_H */
diff --git a/dhcpv6.c b/dhcpv6.c
index 67307d9..32494e9 100644
--- a/dhcpv6.c
+++ b/dhcpv6.c
@@ -31,6 +31,7 @@
#include "passt.h"
#include "tap.h"
#include "log.h"
+#include "fwd.h"
/**
* struct opt_hdr - DHCPv6 option header
@@ -564,6 +565,7 @@ int dhcpv6(struct ctx *c, struct iov_tail *data,
struct opt_hdr client_id_storage;
/* cppcheck-suppress [variableScope,unmatchedSuppression] */
struct opt_ia_na ia_storage;
+ struct in6_addr *ia_addr = NULL;
const struct in6_addr *src;
struct msg_hdr mh_storage;
const struct msg_hdr *mh;
@@ -612,6 +614,17 @@ int dhcpv6(struct ctx *c, struct iov_tail *data,
if (ia && ntohs(ia->hdr.l) < MIN(OPT_VSIZE(ia_na), OPT_VSIZE(ia_ta)))
return -1;
+ /* Select address to assign */
+ {
+ struct inany_addr_entry *e;
+
+ e = fwd_select_addr(c, AF_INET6, INANY_ADDR_DHCP6,
+ INANY_ADDR_OBSERVED | INANY_ADDR_LINKLOCAL);
+ if (e) {
+ ia_addr = &e->addr.a6;
+ resp.ia_addr.addr = *ia_addr;
+ }
+ }
resp.hdr.type = TYPE_REPLY;
switch (mh->type) {
case TYPE_REQUEST:
@@ -624,7 +637,7 @@ int dhcpv6(struct ctx *c, struct iov_tail *data,
if (mh->type == TYPE_CONFIRM && server_id)
return -1;
- if (dhcpv6_ia_notonlink(data, &first_v6(c)->addr.a6)) {
+ if (dhcpv6_ia_notonlink(data, ia_addr)) {
dhcpv6_send_ia_notonlink(c, data, &client_id_base,
ntohs(client_id->l), mh->xid);
@@ -701,5 +714,5 @@ void dhcpv6_init(const struct ctx *c)
memcpy(resp_not_on_link.server_id.duid_lladdr,
c->our_tap_mac, sizeof(c->our_tap_mac));
- resp.ia_addr.addr = first_v6(c)->addr.a6;
+ /* Address is set dynamically in dhcpv6() */
}
diff --git a/fwd.c b/fwd.c
index fc26eba..e41ae9b 100644
--- a/fwd.c
+++ b/fwd.c
@@ -491,6 +491,88 @@ static bool is_dns_flow(uint8_t proto, const struct flowside *ini)
((ini->oport == 53) || (ini->oport == 853));
}
+/**
+ * fwd_first_usable_addr() - Find first assignable address (read-only)
+ * @c: Execution context
+ * @af: Address family (AF_INET or AF_INET6)
+ * @skip: Flags to skip (e.g., INANY_ADDR_LINKLOCAL | INANY_ADDR_OBSERVED)
+ *
+ * Prefers CONFIGURED over HOST addresses.
+ *
+ * Return: pointer to first usable address, or NULL
+ */
+const struct inany_addr_entry *
+fwd_first_usable_addr(const struct ctx *c, int af, int skip)
+{
+ const struct inany_addr_entry *e;
+
+ for_each_addr(c, e, af) {
+ if (e->flags & skip)
+ continue;
+ if (e->flags & INANY_ADDR_CONFIGURED)
+ return e;
+ }
+
+ for_each_addr(c, e, af) {
+ if (e->flags & skip)
+ continue;
+ if (e->flags & INANY_ADDR_HOST)
+ return e;
+ }
+
+ return NULL;
+}
+
+/**
+ * fwd_select_addr() - Select address for protocol assignment (DHCP/NDP/DHCPv6)
+ * @c: Execution context
+ * @af: Address family (AF_INET or AF_INET6)
+ * @assign_flag: Flag to set on selected address (INANY_ADDR_DHCP, etc.)
+ * @skip: Flags to skip (e.g., INANY_ADDR_LINKLOCAL | INANY_ADDR_OBSERVED)
+ *
+ * Selection priority:
+ * 1. Address already having @assign_flag set
+ * 2. Address with INANY_ADDR_CONFIGURED (user -a option)
+ * 3. Address with INANY_ADDR_HOST (from template interface)
+ *
+ * Return: pointer to selected address entry, or NULL if none found
+ */
+struct inany_addr_entry *fwd_select_addr(struct ctx *c, int af,
+ int assign_flag, int skip)
+{
+ struct inany_addr_entry *e;
+
+ /* First: find address already having assign_flag */
+ for_each_addr(c, e, af) {
+ if (e->flags & skip)
+ continue;
+ if (e->flags & assign_flag)
+ return e;
+ }
+
+ /* Second: find CONFIGURED address, set assign_flag */
+ for_each_addr(c, e, af) {
+ if (e->flags & skip)
+ continue;
+ if (e->flags & INANY_ADDR_CONFIGURED) {
+ e->flags |= assign_flag;
+ return e;
+ }
+ }
+
+ /* Third: find HOST address, set assign_flag */
+ for_each_addr(c, e, af) {
+ if (e->flags & skip)
+ continue;
+ if (e->flags & INANY_ADDR_HOST) {
+ e->flags |= assign_flag;
+ return e;
+ }
+ }
+
+ return NULL;
+}
+
/**
* fwd_guest_addr4() - Get first observed IPv4 guest address
* @c: Execution context
diff --git a/fwd.h b/fwd.h
index 7792582..91b15dc 100644
--- a/fwd.h
+++ b/fwd.h
@@ -9,6 +9,7 @@
union inany_addr;
struct flowside;
+struct inany_addr_entry;
/* Number of ports for both TCP and UDP */
#define NUM_PORTS (1U << 16)
@@ -63,4 +64,9 @@ void fwd_neigh_mac_get(const struct ctx *c, const union inany_addr *addr,
uint8_t *mac);
void fwd_neigh_table_init(const struct ctx *c);
+const struct inany_addr_entry *fwd_first_usable_addr(const struct ctx *c,
+ int af, int skip);
+struct inany_addr_entry *fwd_select_addr(struct ctx *c, int af,
+ int assign_flag, int skip);
+
#endif /* FWD_H */
diff --git a/ndp.c b/ndp.c
index f60c298..2211f86 100644
--- a/ndp.c
+++ b/ndp.c
@@ -32,6 +32,7 @@
#include "passt.h"
#include "tap.h"
#include "log.h"
+#include "fwd.h"
#define RT_LIFETIME 65535
@@ -236,7 +237,7 @@ void ndp_unsolicited_na(const struct ctx *c, const struct in6_addr *addr)
* @c: Execution context
* @dst: IPv6 address to send the RA to
*/
-static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
+static void ndp_ra(struct ctx *c, const struct in6_addr *dst)
{
struct ndp_ra ra = {
.ih = {
@@ -257,7 +258,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
.valid_lifetime = ~0U,
.pref_lifetime = ~0U,
},
- .prefix = first_v6(c)->addr.a6,
+ .prefix = IN6ADDR_ANY_INIT,
.source_ll = {
.header = {
.type = OPT_SRC_L2_ADDR,
@@ -265,8 +266,14 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
},
},
};
+ struct inany_addr_entry *e;
unsigned char *ptr = NULL;
+ /* Select address/prefix to advertise */
+ e = fwd_select_addr(c, AF_INET6, INANY_ADDR_NDP, INANY_ADDR_LINKLOCAL);
+ if (e)
+ ra.prefix = e->addr.a6;
+
ptr = &ra.var[0];
if (c->mtu) {
@@ -353,7 +360,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
*
* Return: 0 if not handled here, 1 if handled, -1 on failure
*/
-int ndp(const struct ctx *c, const struct in6_addr *saddr,
+int ndp(struct ctx *c, const struct in6_addr *saddr,
struct iov_tail *data)
{
struct icmp6hdr ih_storage;
@@ -407,7 +414,7 @@ static time_t next_ra;
* @c: Execution context
* @now: Current (monotonic) time
*/
-void ndp_timer(const struct ctx *c, const struct timespec *now)
+void ndp_timer(struct ctx *c, const struct timespec *now)
{
time_t max_rtr_adv_interval = DEFAULT_MAX_RTR_ADV_INTERVAL;
time_t min_rtr_adv_interval, interval;
diff --git a/ndp.h b/ndp.h
index 56b756d..726aef6 100644
--- a/ndp.h
+++ b/ndp.h
@@ -8,9 +8,9 @@
struct icmp6hdr;
-int ndp(const struct ctx *c, const struct in6_addr *saddr,
+int ndp(struct ctx *c, const struct in6_addr *saddr,
struct iov_tail *data);
-void ndp_timer(const struct ctx *c, const struct timespec *now);
+void ndp_timer(struct ctx *c, const struct timespec *now);
void ndp_send_init_req(const struct ctx *c);
void ndp_unsolicited_na(const struct ctx *c, const struct in6_addr *addr);
diff --git a/passt.h b/passt.h
index 7040781..f5f8c68 100644
--- a/passt.h
+++ b/passt.h
@@ -71,6 +71,9 @@ enum passt_modes {
#define INANY_ADDR_HOST BIT(1) /* From host interface */
#define INANY_ADDR_OBSERVED BIT(2) /* Seen in guest traffic */
#define INANY_ADDR_LINKLOCAL BIT(3) /* Link-local address */
+#define INANY_ADDR_DHCP BIT(4) /* IPv4: assigned via DHCP */
+#define INANY_ADDR_DHCP6 BIT(5) /* IPv6: assigned via DHCPv6 */
+#define INANY_ADDR_NDP BIT(6) /* IPv6: prefix via NDP/RA */
/**
* for_each_addr() - Iterate over addresses in unified array
--
2.52.0