Add the SCTP_SUPPORT kernel option.

This is in preparation for enabling a loadable SCTP stack.  Analogous to
IPSEC/IPSEC_SUPPORT, the SCTP_SUPPORT kernel option must be configured
in order to support a loadable SCTP implementation.

Discussed with:	tuexen
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation

share/man/man4/sctp.4

@@ -26,13 +26,16 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 4, 2020
+.Dd June 18, 2020
 .Dt SCTP 4
 .Os
 .Sh NAME
 .Nm sctp
 .Nd Internet Stream Control Transmission Protocol
 .Sh SYNOPSIS
+.Cd "options SCTP"
+.Cd "options SCTP_SUPPORT"
+.Pp
 .In sys/types.h
 .In sys/socket.h
 .In netinet/sctp.h

sys/conf/NOTES

@@ -697,7 +697,12 @@ options 	LIBALIAS
 # the V6 and V4.. since an association can span
 # both a V6 and V4 address at the SAME time :-)
 #
+# The SCTP_SUPPORT option does not enable SCTP, but provides the necessary
+# support for loading SCTP as a loadable kernel module.
+#
 options 	SCTP
+options 	SCTP_SUPPORT
+
 # There are bunches of options:
 # this one turns on all sorts of
 # nastily printing that you can
@@ -710,6 +715,7 @@ options 	SCTP
 # bits and prints.. which makes the code run
 # faster.. if you are not debugging don't use.
 options 	SCTP_DEBUG
+
 #
 # All that options after that turn on specific types of
 # logging. You can monitor CWND growth, flight size
@@ -733,7 +739,6 @@ options 	SCTP_PACKET_LOGGING
 options 	SCTP_LTRACE_CHUNKS
 options 	SCTP_LTRACE_ERRORS
 
-
 # altq(9). Enable the base part of the hooks with the ALTQ option.
 # Individual disciplines must be built into the base system and can not be
 # loaded as modules at this point. ALTQ requires a stable TSC so if yours is

sys/conf/options

@@ -476,6 +476,7 @@ XBONEHACK
 # SCTP
 #
 SCTP			opt_sctp.h
+SCTP_SUPPORT		opt_sctp.h
 SCTP_DEBUG		opt_sctp.h # Enable debug printfs
 SCTP_LOCK_LOGGING	opt_sctp.h # Log to KTR lock activity
 SCTP_MBUF_LOGGING	opt_sctp.h # Log to KTR general mbuf aloc/free

sys/kern/uipc_socket.c

@@ -793,7 +793,7 @@ sonewconn(struct socket *head, int connstatus)
 	return (so);
 }
 
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 /*
  * Socket part of sctp_peeloff().  Detach a new socket from an
  * association.  The new socket is returned with a reference.

sys/netinet/in_proto.c

@@ -94,7 +94,7 @@ static struct pr_usrreqs nousrreqs;
 #include <netinet/sctp_pcb.h>
 #include <netinet/sctp.h>
 #include <netinet/sctp_var.h>
-#endif /* SCTP */
+#endif
 
 FEATURE(inet, "Internet Protocol version 4");
 
@@ -324,7 +324,7 @@ SYSCTL_NODE(_net_inet, IPPROTO_UDP, udp, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "UDP");
 SYSCTL_NODE(_net_inet, IPPROTO_TCP, tcp, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "TCP");
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 SYSCTL_NODE(_net_inet, IPPROTO_SCTP, sctp, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "SCTP");
 #endif

sys/netinet/ip_divert.c

@@ -69,7 +69,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
 #endif
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 #include <netinet/sctp_crc32.h>
 #endif
 
@@ -215,7 +215,7 @@ divert_packet(struct mbuf *m, bool incoming)
 		in_delayed_cksum(m);
 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 	}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 	if (m->m_pkthdr.csum_flags & CSUM_SCTP) {
 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;

sys/netinet/ip_output.c

@@ -86,7 +86,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/udp.h>
 #include <netinet/udp_var.h>
 
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 #include <netinet/sctp.h>
 #include <netinet/sctp_crc32.h>
 #endif
@@ -154,7 +154,7 @@ ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, int flags,
 			}
 			m->m_pkthdr.csum_flags |=
 				CSUM_IP_CHECKED | CSUM_IP_VALID;
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 #endif
@@ -185,7 +185,7 @@ ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, int flags,
 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 			m->m_pkthdr.csum_data = 0xffff;
 		}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 #endif
@@ -753,7 +753,7 @@ ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
 			goto bad;
 		}
 	}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
 		m = mb_unmapped_to_ext(m);
 		if (m == NULL) {
@@ -905,7 +905,7 @@ ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
 		in_delayed_cksum(m0);
 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 	}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
 		m0 = mb_unmapped_to_ext(m0);
 		if (m0 == NULL) {

sys/netinet/sctp_crc32.c

@@ -37,18 +37,17 @@ __FBSDID("$FreeBSD$");
 
 #include "opt_sctp.h"
 
-#include <sys/gsb_crc32.h>
-#ifdef SCTP
-#include <netinet/sctp_os.h>
-#include <netinet/sctp.h>
-#include <netinet/sctp_crc32.h>
-#include <netinet/sctp_pcb.h>
-#else
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/gsb_crc32.h>
 #include <sys/mbuf.h>
 
+#include <netinet/sctp.h>
+#include <netinet/sctp_crc32.h>
+#ifdef SCTP
+#include <netinet/sctp_os.h>
 #include <netinet/sctp_crc32.h>
+#include <netinet/sctp_pcb.h>
 #endif
 
 static uint32_t
@@ -117,7 +116,7 @@ sctp_calculate_cksum(struct mbuf *m, uint32_t offset)
 	return (base);
 }
 
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 /*
  * Compute and insert the SCTP checksum in network byte order for a given
  * mbuf chain m which contains an SCTP packet starting at offset.
@@ -128,8 +127,10 @@ sctp_delayed_cksum(struct mbuf *m, uint32_t offset)
 	uint32_t checksum;
 
 	checksum = sctp_calculate_cksum(m, offset);
+#ifdef SCTP
 	SCTP_STAT_DECR(sctps_sendhwcrc);
 	SCTP_STAT_INCR(sctps_sendswcrc);
+#endif
 	offset += offsetof(struct sctphdr, checksum);
 
 	if (offset + sizeof(uint32_t) > (uint32_t)(m->m_pkthdr.len)) {

sys/netinet/sctp_crc32.h

@@ -40,7 +40,7 @@ __FBSDID("$FreeBSD$");
 
 #if defined(_KERNEL)
 uint32_t sctp_calculate_cksum(struct mbuf *, uint32_t);
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 void sctp_delayed_cksum(struct mbuf *, uint32_t offset);
 #endif
 #endif				/* _KERNEL */

sys/netinet6/in6_proto.c

@@ -429,7 +429,7 @@ SYSCTL_NODE(_net_inet6,	IPPROTO_UDP, udp6, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "UDP6");
 SYSCTL_NODE(_net_inet6,	IPPROTO_TCP, tcp6, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "TCP6");
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 SYSCTL_NODE(_net_inet6,	IPPROTO_SCTP, sctp6, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "SCTP6");
 #endif

sys/netinet6/ip6_forward.c

@@ -360,7 +360,7 @@ ip6_forward(struct mbuf *m, int srcrt)
 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 			m->m_pkthdr.csum_data = 0xffff;
 		}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 #endif

sys/netinet6/ip6_output.c

@@ -114,7 +114,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/in6_rss.h>
 
 #include <netipsec/ipsec_support.h>
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 #include <netinet/sctp.h>
 #include <netinet/sctp_crc32.h>
 #endif
@@ -221,7 +221,7 @@ ip6_output_delayed_csum(struct mbuf *m, struct ifnet *ifp, int csum_flags,
 	    __func__, __LINE__, plen, optlen, m, ifp, csum_flags, frag));
 
 	if ((csum_flags & CSUM_DELAY_DATA_IPV6) ||
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 	    (csum_flags & CSUM_SCTP_IPV6) ||
 #endif
 	    (!frag && (ifp->if_capenable & IFCAP_NOMAP) == 0)) {
@@ -238,7 +238,7 @@ ip6_output_delayed_csum(struct mbuf *m, struct ifnet *ifp, int csum_flags,
 			    sizeof(struct ip6_hdr) + optlen);
 			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
 		}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 		if (csum_flags & CSUM_SCTP_IPV6) {
 			sctp_delayed_cksum(m, sizeof(struct ip6_hdr) + optlen);
 			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
@@ -1041,7 +1041,7 @@ ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 				m->m_pkthdr.csum_data = 0xffff;
 			}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 #endif
@@ -1073,7 +1073,7 @@ ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
 			m->m_pkthdr.csum_data = 0xffff;
 		}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
 #endif

sys/netipsec/ipsec_output.c

@@ -71,7 +71,7 @@
 #ifdef INET6
 #include <netinet/icmp6.h>
 #endif
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 #include <netinet/sctp_crc32.h>
 #endif
 
@@ -326,7 +326,7 @@ ipsec4_common_output(struct mbuf *m, struct inpcb *inp, int forwarding)
 			in_delayed_cksum(m);
 			m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 		}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 		if (m->m_pkthdr.csum_flags & CSUM_SCTP) {
 			struct ip *ip = mtod(m, struct ip *);
 
@@ -621,7 +621,7 @@ ipsec6_common_output(struct mbuf *m, struct inpcb *inp, int forwarding)
 			    sizeof(struct ip6_hdr), sizeof(struct ip6_hdr));
 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
 		}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
 			sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
 			m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;

sys/netpfil/pf/pf.c

@@ -40,9 +40,9 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include "opt_bpf.h"
 #include "opt_inet.h"
 #include "opt_inet6.h"
-#include "opt_bpf.h"
 #include "opt_pf.h"
 #include "opt_sctp.h"
 
@@ -103,7 +103,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet6/scope6_var.h>
 #endif /* INET6 */
 
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 #include <netinet/sctp_crc32.h>
 #endif
 
@@ -5474,7 +5474,7 @@ pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp,
 		in_delayed_cksum(m0);
 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
 	}
-#ifdef SCTP
+#if defined(SCTP) || defined(SCTP_SUPPORT)
 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
 		sctp_delayed_cksum(m0, (uint32_t)(ip->ip_hl << 2));
 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;