From 2fa1cef0167ca330a2d1abd865c3e465cd032230 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Mon, 28 Feb 2022 22:17:32 +0100 Subject: [PATCH] arp, dhcp: Fix strict aliasing warnings reported by gcc 4.9 with -Ofast Signed-off-by: Stefano Brivio --- arp.c | 3 ++- dhcp.c | 14 +++++++------- 2 files changed, 9 insertions(+), 8 deletions(-) diff --git a/arp.c b/arp.c index b5af49f..3195692 100644 --- a/arp.c +++ b/arp.c @@ -58,7 +58,8 @@ int arp(struct ctx *c, struct ethhdr *eh, size_t len) /* Discard announcements (but not 0.0.0.0 "probes"): we might have the * same IP address, hide that. */ - if (*((uint32_t *)&am->sip) && !memcmp(am->sip, am->tip, 4)) + if (memcmp(am->sip, (unsigned char[4]){ 0, 0, 0, 0 }, 4) && + !memcmp(am->sip, am->tip, 4)) return 1; /* Don't resolve our own address, either. */ diff --git a/dhcp.c b/dhcp.c index ab1249c..197a515 100644 --- a/dhcp.c +++ b/dhcp.c @@ -40,9 +40,9 @@ struct opt { int sent; int slen; - unsigned char s[255]; + uint8_t s[255]; int clen; - unsigned char c[255]; + uint8_t c[255]; }; static struct opt opts[255]; @@ -312,9 +312,9 @@ int dhcp(struct ctx *c, struct ethhdr *eh, size_t len) m->chaddr[3], m->chaddr[4], m->chaddr[5]); m->yiaddr = c->addr4; - *(unsigned long *)opts[1].s = c->mask4; - *(unsigned long *)opts[3].s = c->gw4; - *(unsigned long *)opts[54].s = c->gw4; + memcpy(opts[1].s, &c->mask4, sizeof(c->mask4)); + memcpy(opts[3].s, &c->gw4, sizeof(c->gw4)); + memcpy(opts[54].s, &c->gw4, sizeof(c->gw4)); /* If the gateway is not on the assigned subnet, send an option 121 * (Classless Static Routing) adding a dummy route to it. @@ -323,8 +323,8 @@ int dhcp(struct ctx *c, struct ethhdr *eh, size_t len) /* a.b.c.d/32:0.0.0.0, 0:a.b.c.d */ opts[121].slen = 14; opts[121].s[0] = 32; - *(unsigned long *)&opts[121].s[1] = c->gw4; - *(unsigned long *)&opts[121].s[10] = c->gw4; + memcpy(opts[121].s + 1, &c->gw4, sizeof(c->gw4)); + memcpy(opts[121].s + 10, &c->gw4, sizeof(c->gw4)); } if (c->mtu != -1) {