git: 20d59403961d - main - kernel: deprecate Internet Class A/B/C
Date: Tue, 09 Nov 2021 15:36:01 UTC
The branch main has been updated by karels:
URL: https://cgit.FreeBSD.org/src/commit/?id=20d59403961d531467cfab22163f49c131cc8b55
commit 20d59403961d531467cfab22163f49c131cc8b55
Author: Mike Karels <karels@FreeBSD.org>
AuthorDate: 2021-10-27 03:01:09 +0000
Commit: Mike Karels <karels@FreeBSD.org>
CommitDate: 2021-11-09 15:32:38 +0000
kernel: deprecate Internet Class A/B/C
Hide historical Class A/B/C macros unless IN_HISTORICAL_NETS is defined;
define it for user level. Define IN_MULTICAST separately from IN_CLASSD,
and use it in pf instead of IN_CLASSD. Stop using class for setting
default masks when not specified; instead, define new default mask
(24 bits). Warn when an Internet address is set without a mask.
MFC after: 1 month
Reviewed by: cy
Differential Revision: https://reviews.freebsd.org/D32708
---
sys/contrib/ipfilter/netinet/fil.c | 2 +-
sys/netinet/in.c | 19 +++++++++----------
sys/netinet/in.h | 22 +++++++++++++++++-----
sys/nfs/bootp_subr.c | 16 ++++++++--------
4 files changed, 35 insertions(+), 24 deletions(-)
diff --git a/sys/contrib/ipfilter/netinet/fil.c b/sys/contrib/ipfilter/netinet/fil.c
index c04015c2b41e..89f50c261474 100644
--- a/sys/contrib/ipfilter/netinet/fil.c
+++ b/sys/contrib/ipfilter/netinet/fil.c
@@ -1715,7 +1715,7 @@ ipf_pr_ipv4hdr(fin)
fin->fin_crc += fi->fi_saddr;
fi->fi_daddr = ip->ip_dst.s_addr;
fin->fin_crc += fi->fi_daddr;
- if (IN_CLASSD(ntohl(fi->fi_daddr)))
+ if (IN_MULTICAST(ntohl(fi->fi_daddr)))
fin->fin_flx |= FI_MULTICAST|FI_MBCAST;
/*
diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index 8eb20f0f2d27..6bc4f638a98a 100644
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -449,18 +449,17 @@ in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
ia->ia_sockmask = *mask;
ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
} else {
- in_addr_t i = ntohl(addr->sin_addr.s_addr);
-
/*
- * Be compatible with network classes, if netmask isn't
- * supplied, guess it based on classes.
+ * If netmask isn't supplied, use default for now.
+ * This is deprecated for interfaces other than loopback
+ * or point-to-point; warn in other cases. In the future
+ * we should return an error rather than warning.
*/
- if (IN_CLASSA(i))
- ia->ia_subnetmask = IN_CLASSA_NET;
- else if (IN_CLASSB(i))
- ia->ia_subnetmask = IN_CLASSB_NET;
- else
- ia->ia_subnetmask = IN_CLASSC_NET;
+ if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0)
+ printf("%s: set address: WARNING: network mask"
+ " should be specified; using default mask\n",
+ ifp->if_xname);
+ ia->ia_subnetmask = IN_NETMASK_DEFAULT;
ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
}
ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask;
diff --git a/sys/netinet/in.h b/sys/netinet/in.h
index 0506f1739e9b..92d150701422 100644
--- a/sys/netinet/in.h
+++ b/sys/netinet/in.h
@@ -342,10 +342,15 @@ __END_DECLS
#define IPPORT_MAX 65535
/*
- * Definitions of bits in internet address integers.
- * On subnets, the decomposition of addresses to host and net parts
- * is done according to subnet mask, not the masks here.
+ * Historical definitions of bits in internet address integers
+ * (pre-CIDR). Class A/B/C are long obsolete, and now deprecated.
+ * Hide these definitions from the kernel unless IN_HISTORICAL_NETS
+ * is defined. Provide the historical definitions to user level for now.
*/
+#ifndef _KERNEL
+#define IN_HISTORICAL_NETS
+#endif
+#ifdef IN_HISTORICAL_NETS
#define IN_CLASSA(i) (((in_addr_t)(i) & 0x80000000) == 0)
#define IN_CLASSA_NET 0xff000000
#define IN_CLASSA_NSHIFT 24
@@ -362,12 +367,17 @@ __END_DECLS
#define IN_CLASSC_NET 0xffffff00
#define IN_CLASSC_NSHIFT 8
#define IN_CLASSC_HOST 0x000000ff
+#endif /* IN_HISTORICAL_NETS */
+
+#define IN_NETMASK_DEFAULT 0xffffff00 /* mask when forced to guess */
-#define IN_CLASSD(i) (((in_addr_t)(i) & 0xf0000000) == 0xe0000000)
+#define IN_MULTICAST(i) (((in_addr_t)(i) & 0xf0000000) == 0xe0000000)
+#ifdef IN_HISTORICAL_NETS
+#define IN_CLASSD(i) IN_MULTICAST(i)
#define IN_CLASSD_NET 0xf0000000 /* These ones aren't really */
#define IN_CLASSD_NSHIFT 28 /* net and host fields, but */
#define IN_CLASSD_HOST 0x0fffffff /* routing needn't know. */
-#define IN_MULTICAST(i) IN_CLASSD(i)
+#endif /* IN_HISTORICAL_NETS */
#define IN_EXPERIMENTAL(i) (((in_addr_t)(i) & 0xf0000000) == 0xf0000000)
#define IN_BADCLASS(i) (((in_addr_t)(i) & 0xf0000000) == 0xf0000000)
@@ -398,7 +408,9 @@ __END_DECLS
#define INADDR_ALLMDNS_GROUP ((in_addr_t)0xe00000fb) /* 224.0.0.251 */
#define INADDR_MAX_LOCAL_GROUP ((in_addr_t)0xe00000ff) /* 224.0.0.255 */
+#ifdef IN_HISTORICAL_NETS
#define IN_LOOPBACKNET 127 /* official! */
+#endif /* IN_HISTORICAL_NETS */
#define IN_RFC3021_MASK ((in_addr_t)0xfffffffe)
diff --git a/sys/nfs/bootp_subr.c b/sys/nfs/bootp_subr.c
index 2386a23084da..a6dfbe0334f8 100644
--- a/sys/nfs/bootp_subr.c
+++ b/sys/nfs/bootp_subr.c
@@ -654,7 +654,7 @@ bootpc_call(struct bootpc_globalcontext *gctx, struct thread *td)
error, (int )bootp_so->so_state);
/* Set netmask to 255.0.0.0 */
- sin->sin_addr.s_addr = htonl(IN_CLASSA_NET);
+ sin->sin_addr.s_addr = htonl(0xff000000);
error = ifioctl(bootp_so, SIOCAIFADDR, (caddr_t)ifra,
td);
if (error != 0)
@@ -882,7 +882,7 @@ bootpc_fakeup_interface(struct bootpc_ifcontext *ifctx, struct thread *td)
clear_sinaddr(sin);
sin = (struct sockaddr_in *)&ifra->ifra_mask;
clear_sinaddr(sin);
- sin->sin_addr.s_addr = htonl(IN_CLASSA_NET);
+ sin->sin_addr.s_addr = htonl(0xff000000);
sin = (struct sockaddr_in *)&ifra->ifra_broadaddr;
clear_sinaddr(sin);
sin->sin_addr.s_addr = htonl(INADDR_BROADCAST);
@@ -1485,12 +1485,12 @@ bootpc_decode_reply(struct nfsv3_diskless *nd, struct bootpc_ifcontext *ifctx,
printf("\n");
if (ifctx->gotnetmask == 0) {
- if (IN_CLASSA(ntohl(ifctx->myaddr.sin_addr.s_addr)))
- ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSA_NET);
- else if (IN_CLASSB(ntohl(ifctx->myaddr.sin_addr.s_addr)))
- ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSB_NET);
- else
- ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSC_NET);
+ /*
+ * If there is no netmask, use a default, but we really
+ * need the right mask from the server.
+ */
+ printf("%s: no netmask received!\n", ifctx->ireq.ifr_name);
+ ifctx->netmask.sin_addr.s_addr = htonl(IN_NETMASK_DEFAULT);
}
}