Date: Sun, 26 Dec 2021 11:27:57 -0800 From: Gleb Smirnoff <glebius@freebsd.org> To: Jessica Clarke <jrtc27@freebsd.org> Cc: "src-committers@freebsd.org" <src-committers@freebsd.org>, "dev-commits-src-all@freebsd.org" <dev-commits-src-all@freebsd.org>, "dev-commits-src-main@freebsd.org" <dev-commits-src-main@freebsd.org> Subject: Re: git: eb8dcdeac22d - main - jail: network epoch protection for IP address lists Message-ID: <YcjCPTo4ZBVwpzD%2B@FreeBSD.org> In-Reply-To: <7905A4B0-3308-41E9-BA29-73006E55ED53@freebsd.org> References: <202112261846.1BQIkYd8075256@gitrepo.freebsd.org> <04FFE80E-388E-4028-A6D8-FE6F725C1B5B@freebsd.org> <Yci/ELekUUKuQ%2BwX@FreeBSD.org> <7905A4B0-3308-41E9-BA29-73006E55ED53@freebsd.org>
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On Sun, Dec 26, 2021 at 07:15:58PM +0000, Jessica Clarke wrote: J> > On Sun, Dec 26, 2021 at 07:07:06PM +0000, Jessica Clarke wrote: J> > J> > +struct prison_ip { J> > J> > + struct epoch_context ctx; J> > J> > + uint32_t ips; J> > J> > +#ifdef FUTURE_C J> > J> > + union { J> > J> > + struct in_addr pr_ip4[]; J> > J> > + struct in6_addr pr_ip6[]; J> > J> > + }; J> > J> > +#else /* No future C :( */ J> > J> > +#define PR_IP(pip, i) ((const char *)((pip) + 1) + pr_families[af].size * (i)) J> > J> > +#define PR_IPD(pip, i) ((char *)((pip) + 1) + pr_families[af].size * (i)) J> > J> > +#endif J> > J> > +}; J> > J> J> > J> You can make this work with a prison_ip base and prison_ipv[46] derived J> > J> structs. J> > J> J> > J> As it stands this is quite gross, you’re assuming things about J> > J> alignment, and don’t even have a flexible char[] at the end to J> > J> represent the extra data. J> > J> > Will adding char [] to the end be sufficient to guarantee proper alignment? J> J> No. J> J> > Using prison_ipv[46] derived structs won't work as most functions are now J> > made protocol independent. J> J> Why not? Just cast from prison_ip * to prison_ipv4 * when known/needed? What about this? diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c index f1c81d8813bd..ee8bfadb4a3c 100644 --- a/sys/kern/kern_jail.c +++ b/sys/kern/kern_jail.c @@ -572,11 +572,15 @@ struct prison_ip { struct in_addr pr_ip4[]; struct in6_addr pr_ip6[]; }; +}; #else /* No future C :( */ + struct in_addr pr_ip4[]; #define PR_IP(pip, i) ((const char *)((pip) + 1) + pr_families[af].size * (i)) #define PR_IPD(pip, i) ((char *)((pip) + 1) + pr_families[af].size * (i)) -#endif }; +_Static_assert(__alignof(struct in_addr) == __alignof(struct in6_addr), + "AF_INET and AF_INET6 address alignment shall be the same"); +#endif -- Gleb Smirnoff
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