Re: [PATCH v5 10/12] ndp: Pass queue pair explicitly through NDP send path

On Tue, Jun 16, 2026 at 02:51:28PM +0200, Laurent Vivier wrote:

Add a qpair parameter to ndp(), ndp_send(), ndp_na(), ndp_unsolicited_na(), ndp_ra(), and ndp_send_init_req(), forwarding it to tap_icmp6_send() instead of hardcoding QPAIR_DEFAULT.

ndp_timer() and fwd_neigh_table_update() have no queue pair context and keep using QPAIR_DEFAULT.

No functional change.

Signed-off-by: Laurent Vivier --- fwd.c | 2 +- ndp.c | 40 ++++++++++++++++++++++++---------------- ndp.h | 7 ++++--- tap.c | 4 ++-- 4 files changed, 31 insertions(+), 22 deletions(-)

diff --git a/fwd.c b/fwd.c index 0d0e265b7dc0..1bfe024ada26 100644 --- a/fwd.c +++ b/fwd.c @@ -147,7 +147,7 @@ void fwd_neigh_table_update(const struct ctx *c, const union inany_addr *addr, if (inany_v4(addr)) arp_announce(c, QPAIR_DEFAULT, inany_v4(addr), e->mac); else - ndp_unsolicited_na(c, &addr->a6); + ndp_unsolicited_na(c, QPAIR_DEFAULT, &addr->a6); }

/** diff --git a/ndp.c b/ndp.c index 6269cb38d93f..00d1751ba100 100644 --- a/ndp.c +++ b/ndp.c @@ -175,26 +175,28 @@ struct ndp_ns { /** * ndp_send() - Send an NDP message * @c: Execution context + * @qpair: Queue pair on which to send the message * @dst: IPv6 address to send the message to * @buf: ICMPv6 header + message payload * @l4len: Length of message, including ICMPv6 header */ -static void ndp_send(const struct ctx *c, const struct in6_addr *dst, - const void *buf, size_t l4len) +static void ndp_send(const struct ctx *c, unsigned int qpair, + const struct in6_addr *dst, const void *buf, size_t l4len) { const struct in6_addr *src = &c->ip6.our_tap_ll;

- tap_icmp6_send(c, QPAIR_DEFAULT, src, dst, buf, c->our_tap_mac, l4len); + tap_icmp6_send(c, qpair, src, dst, buf, c->our_tap_mac, l4len); }

/** * ndp_na() - Send an NDP Neighbour Advertisement (NA) message * @c: Execution context + * @qpair: Queue pair on which to send the NA * @dst: IPv6 address to send the NA to * @addr: IPv6 address to advertise */ -static void ndp_na(const struct ctx *c, const struct in6_addr *dst, - const struct in6_addr *addr) +static void ndp_na(const struct ctx *c, unsigned int qpair, + const struct in6_addr *dst, const struct in6_addr *addr) { union inany_addr tgt; struct ndp_na na = { @@ -217,26 +219,30 @@ static void ndp_na(const struct ctx *c, const struct in6_addr *dst, inany_from_af(&tgt, AF_INET6, addr); fwd_neigh_mac_get(c, &tgt, na.target_l2_addr.mac);

- ndp_send(c, dst, &na, sizeof(na)); + ndp_send(c, qpair, dst, &na, sizeof(na)); }

/** * ndp_unsolicited_na() - Send unsolicited NA * @c: Execution context + * @qpair: Queue pair on which to send the NA * @addr: IPv6 address to advertise */ -void ndp_unsolicited_na(const struct ctx *c, const struct in6_addr *addr) +void ndp_unsolicited_na(const struct ctx *c, unsigned int qpair, + const struct in6_addr *addr)

Since this is unsolicited, how would the caller have a better idea of the right qpair than we could here?

{ if (tap_is_ready(c)) - ndp_na(c, &in6addr_ll_all_nodes, addr); + ndp_na(c, qpair, &in6addr_ll_all_nodes, addr); }

/** * ndp_ra() - Send an NDP Router Advertisement (RA) message * @c: Execution context + * @qpair: Queue pair on which to send the RA * @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(const struct ctx *c, unsigned int qpair, + const struct in6_addr *dst) { struct ndp_ra ra = { .ih = { @@ -344,18 +350,19 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst) memcpy(&ra.source_ll.mac, c->our_tap_mac, ETH_ALEN);

/* NOLINTNEXTLINE(clang-analyzer-security.PointerSub) */ - ndp_send(c, dst, &ra, ptr - (unsigned char *)&ra); + ndp_send(c, qpair, dst, &ra, ptr - (unsigned char *)&ra); }

/** * ndp() - Check for NDP solicitations, reply as needed * @c: Execution context + * @qpair: Queue pair on which to send replies * @saddr: Source IPv6 address * @data: Single packet with ICMPv6 header * * 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(const struct ctx *c, unsigned int qpair, const struct in6_addr *saddr, struct iov_tail *data) { struct icmp6hdr ih_storage; @@ -384,13 +391,13 @@ int ndp(const struct ctx *c, const struct in6_addr *saddr,

info("NDP: received NS, sending NA");

- ndp_na(c, saddr, &ns->target_addr); + ndp_na(c, qpair, saddr, &ns->target_addr); } else if (ih->icmp6_type == RS) { if (c->no_ra) return 1;

info("NDP: received RS, sending RA"); - ndp_ra(c, saddr); + ndp_ra(c, qpair, saddr); }

return 1; @@ -448,7 +455,7 @@ void ndp_timer(const struct ctx *c, const struct timespec *now)

info("NDP: sending unsolicited RA, next in %llds", (long long)interval);

- ndp_ra(c, &in6addr_ll_all_nodes); + ndp_ra(c, QPAIR_DEFAULT, &in6addr_ll_all_nodes);

first: next_ra = now->tv_sec + interval; @@ -457,8 +464,9 @@ first: /** * ndp_send_init_req() - Send initial NDP NS to retrieve guest MAC address * @c: Execution context + * @qpair: Queue pair on which to send the request */ -void ndp_send_init_req(const struct ctx *c) +void ndp_send_init_req(const struct ctx *c, unsigned int qpair) { struct ndp_ns ns = { .ih = { @@ -471,5 +479,5 @@ void ndp_send_init_req(const struct ctx *c) .target_addr = c->ip6.addr }; debug("Sending initial NDP NS request for guest MAC address"); - ndp_send(c, &c->ip6.addr, &ns, sizeof(ns)); + ndp_send(c, qpair, &c->ip6.addr, &ns, sizeof(ns)); } diff --git a/ndp.h b/ndp.h index 56b756d8400b..8c168fc199fe 100644 --- a/ndp.h +++ b/ndp.h @@ -8,10 +8,11 @@

struct icmp6hdr;

-int ndp(const struct ctx *c, const struct in6_addr *saddr, +int ndp(const struct ctx *c, unsigned int qpair, const struct in6_addr *saddr, struct iov_tail *data); void ndp_timer(const 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); +void ndp_send_init_req(const struct ctx *c, unsigned int qpair); +void ndp_unsolicited_na(const struct ctx *c, unsigned int qpair, + const struct in6_addr *addr);

#endif /* NDP_H */ diff --git a/tap.c b/tap.c index de1e5269526c..5e9c7a1701bf 100644 --- a/tap.c +++ b/tap.c @@ -1030,7 +1030,7 @@ resume: continue;

ndp_data = data; - if (ndp(c, saddr, &ndp_data)) + if (ndp(c, qpair, saddr, &ndp_data)) continue;

tap_packet_debug(NULL, ip6h, NULL, proto, NULL, 1); @@ -1470,7 +1470,7 @@ static void tap_start_connection(const struct ctx *c, unsigned int qpair) if (c->ifi4) arp_send_init_req(c, qpair); if (c->ifi6 && !c->no_ndp) - ndp_send_init_req(c); + ndp_send_init_req(c, qpair); }

/** -- 2.54.0

-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson