From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- include/net/gue.h | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 include/net/gue.h (limited to 'include/net/gue.h') diff --git a/include/net/gue.h b/include/net/gue.h new file mode 100644 index 000000000..fdad41469 --- /dev/null +++ b/include/net/gue.h @@ -0,0 +1,117 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_GUE_H +#define __NET_GUE_H + +/* Definitions for the GUE header, standard and private flags, lengths + * of optional fields are below. + * + * Diagram of GUE header: + * + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |Ver|C| Hlen | Proto/ctype | Standard flags |P| + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * ~ Fields (optional) ~ + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Private flags (optional, P bit is set) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * ~ Private fields (optional) ~ + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * C bit indicates contol message when set, data message when unset. + * For a control message, proto/ctype is interpreted as a type of + * control message. For data messages, proto/ctype is the IP protocol + * of the next header. + * + * P bit indicates private flags field is present. The private flags + * may refer to options placed after this field. + */ + +struct guehdr { + union { + struct { +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u8 hlen:5, + control:1, + version:2; +#elif defined (__BIG_ENDIAN_BITFIELD) + __u8 version:2, + control:1, + hlen:5; +#else +#error "Please fix " +#endif + __u8 proto_ctype; + __be16 flags; + }; + __be32 word; + }; +}; + +/* Standard flags in GUE header */ + +#define GUE_FLAG_PRIV htons(1<<0) /* Private flags are in options */ +#define GUE_LEN_PRIV 4 + +#define GUE_FLAGS_ALL (GUE_FLAG_PRIV) + +/* Private flags in the private option extension */ + +#define GUE_PFLAG_REMCSUM htonl(1 << 31) +#define GUE_PLEN_REMCSUM 4 + +#define GUE_PFLAGS_ALL (GUE_PFLAG_REMCSUM) + +/* Functions to compute options length corresponding to flags. + * If we ever have a lot of flags this can be potentially be + * converted to a more optimized algorithm (table lookup + * for instance). + */ +static inline size_t guehdr_flags_len(__be16 flags) +{ + return ((flags & GUE_FLAG_PRIV) ? GUE_LEN_PRIV : 0); +} + +static inline size_t guehdr_priv_flags_len(__be32 flags) +{ + return 0; +} + +/* Validate standard and private flags. Returns non-zero (meaning invalid) + * if there is an unknown standard or private flags, or the options length for + * the flags exceeds the options length specific in hlen of the GUE header. + */ +static inline int validate_gue_flags(struct guehdr *guehdr, size_t optlen) +{ + __be16 flags = guehdr->flags; + size_t len; + + if (flags & ~GUE_FLAGS_ALL) + return 1; + + len = guehdr_flags_len(flags); + if (len > optlen) + return 1; + + if (flags & GUE_FLAG_PRIV) { + /* Private flags are last four bytes accounted in + * guehdr_flags_len + */ + __be32 pflags = *(__be32 *)((void *)&guehdr[1] + + len - GUE_LEN_PRIV); + + if (pflags & ~GUE_PFLAGS_ALL) + return 1; + + len += guehdr_priv_flags_len(pflags); + if (len > optlen) + return 1; + } + + return 0; +} + +#endif -- cgit v1.2.3