From: David Gibson <david@gibson.dropbear.id.au>
To: Stefano Brivio <sbrivio@redhat.com>, passt-dev@passt.top
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 4/6] ndp: Use struct assignment in preference to memcpy() for IPv6 addresses
Date: Tue, 12 Nov 2024 15:06:16 +1100 [thread overview]
Message-ID: <20241112040618.1804081-5-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20241112040618.1804081-1-david@gibson.dropbear.id.au>
There are a number of places we can simply assign IPv6 addresses about,
rather than the current mildly ugly memcpy().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
ndp.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/ndp.c b/ndp.c
index e876c34..5fda0f5 100644
--- a/ndp.c
+++ b/ndp.c
@@ -158,7 +158,7 @@ struct ndp_ra {
unsigned char var[sizeof(struct opt_mtu) + sizeof(struct opt_rdnss) +
sizeof(struct opt_dnssl)];
-} __attribute__((packed));
+} __attribute__((packed, aligned(__alignof__(struct in6_addr))));
/**
* struct ndp_ns - NDP Neighbor Solicitation (NS) message
@@ -168,7 +168,7 @@ struct ndp_ra {
struct ndp_ns {
struct icmp6hdr ih;
struct in6_addr target_addr;
-} __attribute__((packed));
+} __attribute__((packed, aligned(__alignof__(struct in6_addr))));
/**
* ndp_send() - Send an NDP message
@@ -192,7 +192,7 @@ static void ndp_send(const struct ctx *c, const struct in6_addr *dst,
* @addr: IPv6 address to advertise
*/
static void ndp_na(const struct ctx *c, const struct in6_addr *dst,
- const void *addr)
+ const struct in6_addr *addr)
{
struct ndp_na na = {
.ih = {
@@ -202,6 +202,7 @@ static void ndp_na(const struct ctx *c, const struct in6_addr *dst,
.icmp6_solicited = 1,
.icmp6_override = 1,
},
+ .target_addr = *addr,
.target_l2_addr = {
.header = {
.type = OPT_TARGET_L2_ADDR,
@@ -210,7 +211,6 @@ static void ndp_na(const struct ctx *c, const struct in6_addr *dst,
}
};
- memcpy(&na.target_addr, addr, sizeof(na.target_addr));
memcpy(na.target_l2_addr.mac, c->our_tap_mac, ETH_ALEN);
ndp_send(c, dst, &na, sizeof(na));
@@ -242,6 +242,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
.valid_lifetime = ~0U,
.pref_lifetime = ~0U,
},
+ .prefix = c->ip6.addr,
.source_ll = {
.header = {
.type = OPT_SRC_L2_ADDR,
@@ -251,8 +252,6 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
};
unsigned char *ptr = NULL;
- memcpy(&ra.prefix, &c->ip6.addr, sizeof(ra.prefix));
-
ptr = &ra.var[0];
if (c->mtu != -1) {
@@ -282,8 +281,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
.lifetime = ~0U,
};
for (i = 0; i < n; i++) {
- memcpy(&rdnss->dns[i], &c->ip6.dns[i],
- sizeof(rdnss->dns[i]));
+ rdnss->dns[i] = c->ip6.dns[i];
}
ptr += offsetof(struct opt_rdnss, dns) +
i * sizeof(rdnss->dns[0]);
--
@@ -158,7 +158,7 @@ struct ndp_ra {
unsigned char var[sizeof(struct opt_mtu) + sizeof(struct opt_rdnss) +
sizeof(struct opt_dnssl)];
-} __attribute__((packed));
+} __attribute__((packed, aligned(__alignof__(struct in6_addr))));
/**
* struct ndp_ns - NDP Neighbor Solicitation (NS) message
@@ -168,7 +168,7 @@ struct ndp_ra {
struct ndp_ns {
struct icmp6hdr ih;
struct in6_addr target_addr;
-} __attribute__((packed));
+} __attribute__((packed, aligned(__alignof__(struct in6_addr))));
/**
* ndp_send() - Send an NDP message
@@ -192,7 +192,7 @@ static void ndp_send(const struct ctx *c, const struct in6_addr *dst,
* @addr: IPv6 address to advertise
*/
static void ndp_na(const struct ctx *c, const struct in6_addr *dst,
- const void *addr)
+ const struct in6_addr *addr)
{
struct ndp_na na = {
.ih = {
@@ -202,6 +202,7 @@ static void ndp_na(const struct ctx *c, const struct in6_addr *dst,
.icmp6_solicited = 1,
.icmp6_override = 1,
},
+ .target_addr = *addr,
.target_l2_addr = {
.header = {
.type = OPT_TARGET_L2_ADDR,
@@ -210,7 +211,6 @@ static void ndp_na(const struct ctx *c, const struct in6_addr *dst,
}
};
- memcpy(&na.target_addr, addr, sizeof(na.target_addr));
memcpy(na.target_l2_addr.mac, c->our_tap_mac, ETH_ALEN);
ndp_send(c, dst, &na, sizeof(na));
@@ -242,6 +242,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
.valid_lifetime = ~0U,
.pref_lifetime = ~0U,
},
+ .prefix = c->ip6.addr,
.source_ll = {
.header = {
.type = OPT_SRC_L2_ADDR,
@@ -251,8 +252,6 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
};
unsigned char *ptr = NULL;
- memcpy(&ra.prefix, &c->ip6.addr, sizeof(ra.prefix));
-
ptr = &ra.var[0];
if (c->mtu != -1) {
@@ -282,8 +281,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst)
.lifetime = ~0U,
};
for (i = 0; i < n; i++) {
- memcpy(&rdnss->dns[i], &c->ip6.dns[i],
- sizeof(rdnss->dns[i]));
+ rdnss->dns[i] = c->ip6.dns[i];
}
ptr += offsetof(struct opt_rdnss, dns) +
i * sizeof(rdnss->dns[0]);
--
2.47.0
next prev parent reply other threads:[~2024-11-12 4:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-12 4:06 [PATCH 0/6] ndp: Unsolicited RAs David Gibson
2024-11-12 4:06 ` [PATCH 1/6] ndp: Remove redundant update to addr_seen David Gibson
2024-11-12 4:06 ` [PATCH 2/6] ndp: Add ndp_send() helper David Gibson
2024-11-12 4:06 ` [PATCH 3/6] ndp: Split out helpers for sending specific NDP message types David Gibson
2024-11-13 1:14 ` Stefano Brivio
2024-11-13 2:07 ` David Gibson
2024-11-12 4:06 ` David Gibson [this message]
2024-11-12 4:06 ` [PATCH 5/6] ndp: Make route lifetime a #define David Gibson
2024-11-12 4:06 ` [PATCH 6/6] ndp: Send unsolicited Router Advertisements David Gibson
2024-11-13 1:14 ` Stefano Brivio
2024-11-13 3:01 ` David Gibson
2024-11-13 8:18 ` Stefano Brivio
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