Module Name: src Committed By: roy Date: Fri Feb 12 19:57:49 UTC 2021
Modified Files: src/sys/net: if_gre.c if_gre.h Log Message: if_gre: Ensure that gre_h is aligned To generate a diff of this commit: cvs rdiff -u -r1.177 -r1.178 src/sys/net/if_gre.c cvs rdiff -u -r1.47 -r1.48 src/sys/net/if_gre.h Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/net/if_gre.c diff -u src/sys/net/if_gre.c:1.177 src/sys/net/if_gre.c:1.178 --- src/sys/net/if_gre.c:1.177 Wed Jan 29 04:18:34 2020 +++ src/sys/net/if_gre.c Fri Feb 12 19:57:49 2021 @@ -1,4 +1,4 @@ -/* $NetBSD: if_gre.c,v 1.177 2020/01/29 04:18:34 thorpej Exp $ */ +/* $NetBSD: if_gre.c,v 1.178 2021/02/12 19:57:49 roy Exp $ */ /* * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc. @@ -45,7 +45,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: if_gre.c,v 1.177 2020/01/29 04:18:34 thorpej Exp $"); +__KERNEL_RCSID(0, "$NetBSD: if_gre.c,v 1.178 2021/02/12 19:57:49 roy Exp $"); #ifdef _KERNEL_OPT #include "opt_atalk.h" @@ -395,10 +395,26 @@ gre_receive(struct socket *so, void *arg sc->sc_error_ev.ev_count++; return; } - if (m->m_len < sizeof(*gh) && (m = m_pullup(m, sizeof(*gh))) == NULL) { - GRE_DPRINTF(sc, "m_pullup failed\n"); - sc->sc_pullup_ev.ev_count++; - return; + + /* If the GRE header is not aligned, slurp it up into a new + * mbuf with space for link headers, in the event we forward + * it. Otherwise, if it is aligned, make sure the entire + * base GRE header is in the first mbuf of the chain. + */ + if (GRE_HDR_ALIGNED_P(mtod(m, void *)) == 0) { + if ((m = m_copyup(m, sizeof(struct gre_h), + (max_linkhdr + 3) & ~3)) == NULL) { + /* XXXJRT new stat, please */ + GRE_DPRINTF(sc, "m_copyup failed\n"); + sc->sc_pullup_ev.ev_count++; + return; + } + } else if (__predict_false(m->m_len < sizeof(struct gre_h))) { + if ((m = m_pullup(m, sizeof(struct gre_h))) == NULL) { + GRE_DPRINTF(sc, "m_pullup failed\n"); + sc->sc_pullup_ev.ev_count++; + return; + } } gh = mtod(m, const struct gre_h *); @@ -940,7 +956,6 @@ gre_output(struct ifnet *ifp, struct mbu #endif M_PREPEND(m, sizeof(*gh), M_DONTWAIT); - if (m == NULL) { IF_DROP(&ifp->if_snd); error = ENOBUFS; @@ -948,6 +963,7 @@ gre_output(struct ifnet *ifp, struct mbu } gh = mtod(m, struct gre_h *); + KASSERT(GRE_HDR_ALIGNED_P(gh)); gh->flags = 0; gh->ptype = etype; /* XXX Need to handle IP ToS. Look at how I handle IP TTL. */ Index: src/sys/net/if_gre.h diff -u src/sys/net/if_gre.h:1.47 src/sys/net/if_gre.h:1.48 --- src/sys/net/if_gre.h:1.47 Wed Feb 3 18:13:13 2021 +++ src/sys/net/if_gre.h Fri Feb 12 19:57:49 2021 @@ -1,4 +1,4 @@ -/* $NetBSD: if_gre.h,v 1.47 2021/02/03 18:13:13 roy Exp $ */ +/* $NetBSD: if_gre.h,v 1.48 2021/02/12 19:57:49 roy Exp $ */ /* * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc. @@ -131,6 +131,11 @@ struct gre_h { Present if (rt_pres == 1) */ }; +#ifdef __NO_STRICT_ALIGNMENT +#define GRE_HDR_ALIGNED_P(gh) 1 +#else +#define GRE_HDR_ALIGNED_P(gh) ((((vaddr_t) (gh)) & 3) == 0) +#endif #ifdef __CTASSERT __CTASSERT(sizeof(struct gre_h) == 4); #endif