From 5461fc0c8d9f23956b99f5907f69726a293ccb67 Mon Sep 17 00:00:00 2001 From: Dmitry Safonov Date: Mon, 21 Sep 2020 15:36:52 +0100 Subject: [PATCH] xfrm/compat: Add 64=>32-bit messages translator Provide the kernel-to-user translator under XFRM_USER_COMPAT, that creates for 64-bit xfrm-user message a 32-bit translation and puts it in skb's frag_list. net/compat.c layer provides MSG_CMSG_COMPAT to decide if the message should be taken from skb or frag_list. (used by wext-core which has also an ABI difference) Kernel sends 64-bit xfrm messages to the userspace for: - multicast (monitor events) - netlink dumps Wire up the translator to xfrm_nlmsg_multicast(). Signed-off-by: Dmitry Safonov Signed-off-by: Steffen Klassert --- include/net/xfrm.h | 5 + net/xfrm/xfrm_compat.c | 296 +++++++++++++++++++++++++++++++++++++++++ net/xfrm/xfrm_user.c | 15 ++- 3 files changed, 315 insertions(+), 1 deletion(-) diff --git a/include/net/xfrm.h b/include/net/xfrm.h index fe2e3717da14..5b6cc62c9354 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -2000,7 +2000,12 @@ static inline int xfrm_tunnel_check(struct sk_buff *skb, struct xfrm_state *x, return 0; } +extern const int xfrm_msg_min[XFRM_NR_MSGTYPES]; + struct xfrm_translator { + /* Allocate frag_list and put compat translation there */ + int (*alloc_compat)(struct sk_buff *skb, const struct nlmsghdr *src); + struct module *owner; }; diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c index f01d9af41c55..aece41b44ff2 100644 --- a/net/xfrm/xfrm_compat.c +++ b/net/xfrm/xfrm_compat.c @@ -8,8 +8,304 @@ #include #include +struct compat_xfrm_lifetime_cfg { + compat_u64 soft_byte_limit, hard_byte_limit; + compat_u64 soft_packet_limit, hard_packet_limit; + compat_u64 soft_add_expires_seconds, hard_add_expires_seconds; + compat_u64 soft_use_expires_seconds, hard_use_expires_seconds; +}; /* same size on 32bit, but only 4 byte alignment required */ + +struct compat_xfrm_lifetime_cur { + compat_u64 bytes, packets, add_time, use_time; +}; /* same size on 32bit, but only 4 byte alignment required */ + +struct compat_xfrm_userpolicy_info { + struct xfrm_selector sel; + struct compat_xfrm_lifetime_cfg lft; + struct compat_xfrm_lifetime_cur curlft; + __u32 priority, index; + u8 dir, action, flags, share; + /* 4 bytes additional padding on 64bit */ +}; + +struct compat_xfrm_usersa_info { + struct xfrm_selector sel; + struct xfrm_id id; + xfrm_address_t saddr; + struct compat_xfrm_lifetime_cfg lft; + struct compat_xfrm_lifetime_cur curlft; + struct xfrm_stats stats; + __u32 seq, reqid; + u16 family; + u8 mode, replay_window, flags; + /* 4 bytes additional padding on 64bit */ +}; + +struct compat_xfrm_user_acquire { + struct xfrm_id id; + xfrm_address_t saddr; + struct xfrm_selector sel; + struct compat_xfrm_userpolicy_info policy; + /* 4 bytes additional padding on 64bit */ + __u32 aalgos, ealgos, calgos, seq; +}; + +struct compat_xfrm_userspi_info { + struct compat_xfrm_usersa_info info; + /* 4 bytes additional padding on 64bit */ + __u32 min, max; +}; + +struct compat_xfrm_user_expire { + struct compat_xfrm_usersa_info state; + /* 8 bytes additional padding on 64bit */ + u8 hard; +}; + +struct compat_xfrm_user_polexpire { + struct compat_xfrm_userpolicy_info pol; + /* 8 bytes additional padding on 64bit */ + u8 hard; +}; + +#define XMSGSIZE(type) sizeof(struct type) + +static const int compat_msg_min[XFRM_NR_MSGTYPES] = { + [XFRM_MSG_NEWSA - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info), + [XFRM_MSG_DELSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id), + [XFRM_MSG_GETSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id), + [XFRM_MSG_NEWPOLICY - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info), + [XFRM_MSG_DELPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id), + [XFRM_MSG_GETPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id), + [XFRM_MSG_ALLOCSPI - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userspi_info), + [XFRM_MSG_ACQUIRE - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_acquire), + [XFRM_MSG_EXPIRE - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_expire), + [XFRM_MSG_UPDPOLICY - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_userpolicy_info), + [XFRM_MSG_UPDSA - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_usersa_info), + [XFRM_MSG_POLEXPIRE - XFRM_MSG_BASE] = XMSGSIZE(compat_xfrm_user_polexpire), + [XFRM_MSG_FLUSHSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush), + [XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = 0, + [XFRM_MSG_NEWAE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id), + [XFRM_MSG_GETAE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_aevent_id), + [XFRM_MSG_REPORT - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_report), + [XFRM_MSG_MIGRATE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id), + [XFRM_MSG_NEWSADINFO - XFRM_MSG_BASE] = sizeof(u32), + [XFRM_MSG_GETSADINFO - XFRM_MSG_BASE] = sizeof(u32), + [XFRM_MSG_NEWSPDINFO - XFRM_MSG_BASE] = sizeof(u32), + [XFRM_MSG_GETSPDINFO - XFRM_MSG_BASE] = sizeof(u32), + [XFRM_MSG_MAPPING - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_mapping) +}; + +static struct nlmsghdr *xfrm_nlmsg_put_compat(struct sk_buff *skb, + const struct nlmsghdr *nlh_src, u16 type) +{ + int payload = compat_msg_min[type]; + int src_len = xfrm_msg_min[type]; + struct nlmsghdr *nlh_dst; + + /* Compat messages are shorter or equal to native (+padding) */ + if (WARN_ON_ONCE(src_len < payload)) + return ERR_PTR(-EMSGSIZE); + + nlh_dst = nlmsg_put(skb, nlh_src->nlmsg_pid, nlh_src->nlmsg_seq, + nlh_src->nlmsg_type, payload, nlh_src->nlmsg_flags); + if (!nlh_dst) + return ERR_PTR(-EMSGSIZE); + + memset(nlmsg_data(nlh_dst), 0, payload); + + switch (nlh_src->nlmsg_type) { + /* Compat message has the same layout as native */ + case XFRM_MSG_DELSA: + case XFRM_MSG_DELPOLICY: + case XFRM_MSG_FLUSHSA: + case XFRM_MSG_FLUSHPOLICY: + case XFRM_MSG_NEWAE: + case XFRM_MSG_REPORT: + case XFRM_MSG_MIGRATE: + case XFRM_MSG_NEWSADINFO: + case XFRM_MSG_NEWSPDINFO: + case XFRM_MSG_MAPPING: + WARN_ON_ONCE(src_len != payload); + memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), src_len); + break; + /* 4 byte alignment for trailing u64 on native, but not on compat */ + case XFRM_MSG_NEWSA: + case XFRM_MSG_NEWPOLICY: + case XFRM_MSG_UPDSA: + case XFRM_MSG_UPDPOLICY: + WARN_ON_ONCE(src_len != payload + 4); + memcpy(nlmsg_data(nlh_dst), nlmsg_data(nlh_src), payload); + break; + case XFRM_MSG_EXPIRE: { + const struct xfrm_user_expire *src_ue = nlmsg_data(nlh_src); + struct compat_xfrm_user_expire *dst_ue = nlmsg_data(nlh_dst); + + /* compat_xfrm_user_expire has 4-byte smaller state */ + memcpy(dst_ue, src_ue, sizeof(dst_ue->state)); + dst_ue->hard = src_ue->hard; + break; + } + case XFRM_MSG_ACQUIRE: { + const struct xfrm_user_acquire *src_ua = nlmsg_data(nlh_src); + struct compat_xfrm_user_acquire *dst_ua = nlmsg_data(nlh_dst); + + memcpy(dst_ua, src_ua, offsetof(struct compat_xfrm_user_acquire, aalgos)); + dst_ua->aalgos = src_ua->aalgos; + dst_ua->ealgos = src_ua->ealgos; + dst_ua->calgos = src_ua->calgos; + dst_ua->seq = src_ua->seq; + break; + } + case XFRM_MSG_POLEXPIRE: { + const struct xfrm_user_polexpire *src_upe = nlmsg_data(nlh_src); + struct compat_xfrm_user_polexpire *dst_upe = nlmsg_data(nlh_dst); + + /* compat_xfrm_user_polexpire has 4-byte smaller state */ + memcpy(dst_upe, src_upe, sizeof(dst_upe->pol)); + dst_upe->hard = src_upe->hard; + break; + } + case XFRM_MSG_ALLOCSPI: { + const struct xfrm_userspi_info *src_usi = nlmsg_data(nlh_src); + struct compat_xfrm_userspi_info *dst_usi = nlmsg_data(nlh_dst); + + /* compat_xfrm_user_polexpire has 4-byte smaller state */ + memcpy(dst_usi, src_usi, sizeof(src_usi->info)); + dst_usi->min = src_usi->min; + dst_usi->max = src_usi->max; + break; + } + /* Not being sent by kernel */ + case XFRM_MSG_GETSA: + case XFRM_MSG_GETPOLICY: + case XFRM_MSG_GETAE: + case XFRM_MSG_GETSADINFO: + case XFRM_MSG_GETSPDINFO: + default: + WARN_ONCE(1, "unsupported nlmsg_type %d", nlh_src->nlmsg_type); + return ERR_PTR(-EOPNOTSUPP); + } + + return nlh_dst; +} + +static int xfrm_nla_cpy(struct sk_buff *dst, const struct nlattr *src, int len) +{ + return nla_put(dst, src->nla_type, len, nla_data(src)); +} + +static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src) +{ + switch (src->nla_type) { + case XFRMA_PAD: + /* Ignore */ + return 0; + case XFRMA_ALG_AUTH: + case XFRMA_ALG_CRYPT: + case XFRMA_ALG_COMP: + case XFRMA_ENCAP: + case XFRMA_TMPL: + return xfrm_nla_cpy(dst, src, nla_len(src)); + case XFRMA_SA: + return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_usersa_info)); + case XFRMA_POLICY: + return xfrm_nla_cpy(dst, src, XMSGSIZE(compat_xfrm_userpolicy_info)); + case XFRMA_SEC_CTX: + return xfrm_nla_cpy(dst, src, nla_len(src)); + case XFRMA_LTIME_VAL: + return nla_put_64bit(dst, src->nla_type, nla_len(src), + nla_data(src), XFRMA_PAD); + case XFRMA_REPLAY_VAL: + case XFRMA_REPLAY_THRESH: + case XFRMA_ETIMER_THRESH: + case XFRMA_SRCADDR: + case XFRMA_COADDR: + return xfrm_nla_cpy(dst, src, nla_len(src)); + case XFRMA_LASTUSED: + return nla_put_64bit(dst, src->nla_type, nla_len(src), + nla_data(src), XFRMA_PAD); + case XFRMA_POLICY_TYPE: + case XFRMA_MIGRATE: + case XFRMA_ALG_AEAD: + case XFRMA_KMADDRESS: + case XFRMA_ALG_AUTH_TRUNC: + case XFRMA_MARK: + case XFRMA_TFCPAD: + case XFRMA_REPLAY_ESN_VAL: + case XFRMA_SA_EXTRA_FLAGS: + case XFRMA_PROTO: + case XFRMA_ADDRESS_FILTER: + case XFRMA_OFFLOAD_DEV: + case XFRMA_SET_MARK: + case XFRMA_SET_MARK_MASK: + case XFRMA_IF_ID: + return xfrm_nla_cpy(dst, src, nla_len(src)); + default: + BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID); + WARN_ONCE(1, "unsupported nla_type %d", src->nla_type); + return -EOPNOTSUPP; + } +} + +/* Take kernel-built (64bit layout) and create 32bit layout for userspace */ +static int xfrm_xlate64(struct sk_buff *dst, const struct nlmsghdr *nlh_src) +{ + u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE; + const struct nlattr *nla, *attrs; + struct nlmsghdr *nlh_dst; + int len, remaining; + + nlh_dst = xfrm_nlmsg_put_compat(dst, nlh_src, type); + if (IS_ERR(nlh_dst)) + return PTR_ERR(nlh_dst); + + attrs = nlmsg_attrdata(nlh_src, xfrm_msg_min[type]); + len = nlmsg_attrlen(nlh_src, xfrm_msg_min[type]); + + nla_for_each_attr(nla, attrs, len, remaining) { + int err = xfrm_xlate64_attr(dst, nla); + + if (err) + return err; + } + + nlmsg_end(dst, nlh_dst); + + return 0; +} + +static int xfrm_alloc_compat(struct sk_buff *skb, const struct nlmsghdr *nlh_src) +{ + u16 type = nlh_src->nlmsg_type - XFRM_MSG_BASE; + struct sk_buff *new = NULL; + int err; + + if (WARN_ON_ONCE(type >= ARRAY_SIZE(xfrm_msg_min))) + return -EOPNOTSUPP; + + if (skb_shinfo(skb)->frag_list == NULL) { + new = alloc_skb(skb->len + skb_tailroom(skb), GFP_ATOMIC); + if (!new) + return -ENOMEM; + skb_shinfo(skb)->frag_list = new; + } + + err = xfrm_xlate64(skb_shinfo(skb)->frag_list, nlh_src); + if (err) { + if (new) { + kfree_skb(new); + skb_shinfo(skb)->frag_list = NULL; + } + return err; + } + + return 0; +} + static struct xfrm_translator xfrm_translator = { .owner = THIS_MODULE, + .alloc_compat = xfrm_alloc_compat, }; static int __init xfrm_compat_init(void) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index fbb7d9d06478..3769227ed4e1 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1083,12 +1083,24 @@ static inline int xfrm_nlmsg_multicast(struct net *net, struct sk_buff *skb, u32 pid, unsigned int group) { struct sock *nlsk = rcu_dereference(net->xfrm.nlsk); + struct xfrm_translator *xtr; if (!nlsk) { kfree_skb(skb); return -EPIPE; } + xtr = xfrm_get_translator(); + if (xtr) { + int err = xtr->alloc_compat(skb, nlmsg_hdr(skb)); + + xfrm_put_translator(xtr); + if (err) { + kfree_skb(skb); + return err; + } + } + return nlmsg_multicast(nlsk, skb, pid, group, GFP_ATOMIC); } @@ -2533,7 +2545,7 @@ static int xfrm_send_migrate(const struct xfrm_selector *sel, u8 dir, u8 type, #define XMSGSIZE(type) sizeof(struct type) -static const int xfrm_msg_min[XFRM_NR_MSGTYPES] = { +const int xfrm_msg_min[XFRM_NR_MSGTYPES] = { [XFRM_MSG_NEWSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_info), [XFRM_MSG_DELSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id), [XFRM_MSG_GETSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id), @@ -2556,6 +2568,7 @@ static const int xfrm_msg_min[XFRM_NR_MSGTYPES] = { [XFRM_MSG_NEWSPDINFO - XFRM_MSG_BASE] = sizeof(u32), [XFRM_MSG_GETSPDINFO - XFRM_MSG_BASE] = sizeof(u32), }; +EXPORT_SYMBOL_GPL(xfrm_msg_min); #undef XMSGSIZE