litmus-rt.git - The LITMUS^RT kernel.

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author	Ingo Molnar <mingo@elte.hu>	2009-02-22 06:06:57 -0500
committer	Ingo Molnar <mingo@elte.hu>	2009-02-25 12:38:07 -0500
commit	3c972c2444dcb7088999c32b8c5a7ab3b8a6c0b6 (patch)
tree	0d89d2cfff1b3b32192ed54c70ee183356a11191 /kernel/time/ntp.c
parent	53bbfa9e9437e70b322368e82c723112d690e304 (diff)

time: ntp: simplify the second_overflow() code flow

Impact: cleanup, no functionality changed Instead of a hierarchy of conditions, transform them to clean gradual conditions and return's. This makes the flow easier to read and makes the purpose of the function easier to understand. kernel/time/ntp.o: text data bss dec hex filename 2552 170 168 2890 b4a ntp.o.before 2552 170 168 2890 b4a ntp.o.after md5: eae1275df0b7d6290c13f6f6f8f05c8c ntp.o.before.asm eae1275df0b7d6290c13f6f6f8f05c8c ntp.o.after.asm Signed-off-by: Ingo Molnar <mingo@elte.hu>

Diffstat (limited to 'kernel/time/ntp.c')

-rw-r--r--

kernel/time/ntp.c

1 files changed, 17 insertions, 12 deletions


diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 3479ec48e604..1fa6615b317a 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c
@@ -232,19 +232,24 @@ void second_overflow(void)
232	time_offset -= time_adj;	232	time_offset -= time_adj;
233	tick_length += time_adj;	233	tick_length += time_adj;
234		234
235	if (unlikely(time_adjust)) {	235	if (!time_adjust)
236	if (time_adjust > MAX_TICKADJ) {	236	return;
237	time_adjust -= MAX_TICKADJ;	237
238	tick_length += MAX_TICKADJ_SCALED;	238	if (time_adjust > MAX_TICKADJ) {
239	} else if (time_adjust < -MAX_TICKADJ) {	239	time_adjust -= MAX_TICKADJ;
240	time_adjust += MAX_TICKADJ;	240	tick_length += MAX_TICKADJ_SCALED;
241	tick_length -= MAX_TICKADJ_SCALED;	241	return;
242	} else {
243	tick_length += (s64)(time_adjust * NSEC_PER_USEC /
244	NTP_INTERVAL_FREQ) << NTP_SCALE_SHIFT;
245	time_adjust = 0;
246	}
247	}	242	}
		243
		244	if (time_adjust < -MAX_TICKADJ) {
		245	time_adjust += MAX_TICKADJ;
		246	tick_length -= MAX_TICKADJ_SCALED;
		247	return;
		248	}
		249
		250	tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
		251	<< NTP_SCALE_SHIFT;
		252	time_adjust = 0;
248	}	253	}
249		254
250	#ifdef CONFIG_GENERIC_CMOS_UPDATE	255	#ifdef CONFIG_GENERIC_CMOS_UPDATE

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/* Kerberos-based RxRPC security * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/module.h> #include <linux/net.h> #include <linux/skbuff.h> #include <linux/udp.h> #include <linux/crypto.h> #include <linux/scatterlist.h> #include <linux/ctype.h> #include <net/sock.h> #include <net/af_rxrpc.h> #define rxrpc_debug rxkad_debug #include "ar-internal.h" #define RXKAD_VERSION 2 #define MAXKRB5TICKETLEN 1024 #define RXKAD_TKT_TYPE_KERBEROS_V5 256 #define ANAME_SZ 40 /* size of authentication name */ #define INST_SZ 40 /* size of principal's instance */ #define REALM_SZ 40 /* size of principal's auth domain */ #define SNAME_SZ 40 /* size of service name */ unsigned rxrpc_debug; module_param_named(debug, rxrpc_debug, uint, S_IWUSR | S_IRUGO); MODULE_PARM_DESC(rxrpc_debug, "rxkad debugging mask"); struct rxkad_level1_hdr { __be32 data_size; /* true data size (excluding padding) */ }; struct rxkad_level2_hdr { __be32 data_size; /* true data size (excluding padding) */ __be32 checksum; /* decrypted data checksum */ }; MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos)"); MODULE_AUTHOR("Red Hat, Inc."); MODULE_LICENSE("GPL"); /* * this holds a pinned cipher so that keventd doesn't get called by the cipher * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE * packets */ static struct crypto_blkcipher *rxkad_ci; static DEFINE_MUTEX(rxkad_ci_mutex); /* * initialise connection security */ static int rxkad_init_connection_security(struct rxrpc_connection *conn) { struct rxrpc_key_payload *payload; struct crypto_blkcipher *ci; int ret; _enter("{%d},{%x}", conn->debug_id, key_serial(conn->key)); payload = conn->key->payload.data; conn->security_ix = payload->k.security_index; ci = crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(ci)) { _debug("no cipher"); ret = PTR_ERR(ci); goto error; } if (crypto_blkcipher_setkey(ci, payload->k.session_key, sizeof(payload->k.session_key)) < 0) BUG(); switch (conn->security_level) { case RXRPC_SECURITY_PLAIN: break; case RXRPC_SECURITY_AUTH: conn->size_align = 8; conn->security_size = sizeof(struct rxkad_level1_hdr); conn->header_size += sizeof(struct rxkad_level1_hdr); break; case RXRPC_SECURITY_ENCRYPT: conn->size_align = 8; conn->security_size = sizeof(struct rxkad_level2_hdr); conn->header_size += sizeof(struct rxkad_level2_hdr); break; default: ret = -EKEYREJECTED; goto error; } conn->cipher = ci; ret = 0; error: _leave(" = %d", ret); return ret; } /* * prime the encryption state with the invariant parts of a connection's * description */ static void rxkad_prime_packet_security(struct rxrpc_connection *conn) { struct rxrpc_key_payload *payload; struct blkcipher_desc desc; struct scatterlist sg[2]; struct rxrpc_crypt iv; struct { __be32 x[4]; } tmpbuf __attribute__((aligned(16))); /* must all be in same page */ _enter(""); if (!conn->key) return; payload = conn->key->payload.data; memcpy(&iv, payload->k.session_key, sizeof(iv)); desc.tfm = conn->cipher; desc.info = iv.x; desc.flags = 0; tmpbuf.x[0] = conn->epoch; tmpbuf.x[1] = conn->cid; tmpbuf.x[2] = 0; tmpbuf.x[3] = htonl(conn->security_ix); memset(sg, 0, sizeof(sg)); sg_set_buf(&sg[0], &tmpbuf, sizeof(tmpbuf)); sg_set_buf(&sg[1], &tmpbuf, sizeof(tmpbuf)); crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); memcpy(&conn->csum_iv, &tmpbuf.x[2], sizeof(conn->csum_iv)); ASSERTCMP(conn->csum_iv.n[0], ==, tmpbuf.x[2]); _leave(""); } /* * partially encrypt a packet (level 1 security) */ static int rxkad_secure_packet_auth(const struct rxrpc_call *call, struct sk_buff *skb, u32 data_size, void *sechdr) { struct rxrpc_skb_priv *sp; struct blkcipher_desc desc; struct rxrpc_crypt iv; struct scatterlist sg[2]; struct { struct rxkad_level1_hdr hdr; __be32 first; /* first four bytes of data and padding */ } tmpbuf __attribute__((aligned(8))); /* must all be in same page */ u16 check; sp = rxrpc_skb(skb); _enter(""); check = ntohl(sp->hdr.seq ^ sp->hdr.callNumber); data_size |= (u32) check << 16; tmpbuf.hdr.data_size = htonl(data_size); memcpy(&tmpbuf.first, sechdr + 4, sizeof(tmpbuf.first)); /* start the encryption afresh */ memset(&iv, 0, sizeof(iv)); desc.tfm = call->conn->cipher; desc.info = iv.x; desc.flags = 0; memset(sg, 0, sizeof(sg)); sg_set_buf(&sg[0], &tmpbuf, sizeof(tmpbuf)); sg_set_buf(&sg[1], &tmpbuf, sizeof(tmpbuf)); crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); memcpy(sechdr, &tmpbuf, sizeof(tmpbuf)); _leave(" = 0"); return 0; } /* * wholly encrypt a packet (level 2 security) */ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call, struct sk_buff *skb, u32 data_size, void *sechdr) { const struct rxrpc_key_payload *payload; struct rxkad_level2_hdr rxkhdr __attribute__((aligned(8))); /* must be all on one page */ struct rxrpc_skb_priv *sp; struct blkcipher_desc desc; struct rxrpc_crypt iv; struct scatterlist sg[16]; struct sk_buff *trailer; unsigned len; u16 check; int nsg; sp = rxrpc_skb(skb); _enter(""); check = ntohl(sp->hdr.seq ^ sp->hdr.callNumber); rxkhdr.data_size = htonl(data_size | (u32) check << 16); rxkhdr.checksum = 0; /* encrypt from the session key */ payload = call->conn->key->payload.data; memcpy(&iv, payload->k.session_key, sizeof(iv)); desc.tfm = call->conn->cipher; desc.info = iv.x; desc.flags = 0; memset(sg, 0, sizeof(sg[0]) * 2); sg_set_buf(&sg[0], sechdr, sizeof(rxkhdr)); sg_set_buf(&sg[1], &rxkhdr, sizeof(rxkhdr)); crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(rxkhdr)); /* we want to encrypt the skbuff in-place */ nsg = skb_cow_data(skb, 0, &trailer); if (nsg < 0 || nsg > 16) return -ENOMEM; len = data_size + call->conn->size_align - 1; len &= ~(call->conn->size_align - 1); skb_to_sgvec(skb, sg, 0, len); crypto_blkcipher_encrypt_iv(&desc, sg, sg, len); _leave(" = 0"); return 0; } /* * checksum an RxRPC packet header */ static int rxkad_secure_packet(const struct rxrpc_call *call, struct sk_buff *skb, size_t data_size, void *sechdr) { struct rxrpc_skb_priv *sp; struct blkcipher_desc desc; struct rxrpc_crypt iv; struct scatterlist sg[2]; struct { __be32 x[2]; } tmpbuf __attribute__((aligned(8))); /* must all be in same page */ __be32 x; int ret; sp = rxrpc_skb(skb); _enter("{%d{%x}},{#%u},%zu,", call->debug_id, key_serial(call->conn->key), ntohl(sp->hdr.seq), data_size); if (!call->conn->cipher) return 0; ret = key_validate(call->conn->key); if (ret < 0) return ret; /* continue encrypting from where we left off */ memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); desc.tfm = call->conn->cipher; desc.info = iv.x; desc.flags = 0; /* calculate the security checksum */ x = htonl(call->channel << (32 - RXRPC_CIDSHIFT)); x |= sp->hdr.seq & __constant_cpu_to_be32(0x3fffffff); tmpbuf.x[0] = sp->hdr.callNumber; tmpbuf.x[1] = x; memset(&sg, 0, sizeof(sg)); sg_set_buf(&sg[0], &tmpbuf, sizeof(tmpbuf)); sg_set_buf(&sg[1], &tmpbuf, sizeof(tmpbuf)); crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); x = ntohl(tmpbuf.x[1]); x = (x >> 16) & 0xffff; if (x == 0) x = 1; /* zero checksums are not permitted */ sp->hdr.cksum = htons(x); switch (call->conn->security_level) { case RXRPC_SECURITY_PLAIN: ret = 0; break; case RXRPC_SECURITY_AUTH: ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr); break; case RXRPC_SECURITY_ENCRYPT: ret = rxkad_secure_packet_encrypt(call, skb, data_size, sechdr); break; default: ret = -EPERM; break; } _leave(" = %d [set %hx]", ret, x); return ret; } /* * decrypt partial encryption on a packet (level 1 security) */ static int rxkad_verify_packet_auth(const struct rxrpc_call *call, struct sk_buff *skb, u32 *_abort_code) { struct rxkad_level1_hdr sechdr; struct rxrpc_skb_priv *sp; struct blkcipher_desc desc; struct rxrpc_crypt iv; struct scatterlist sg[2]; struct sk_buff *trailer; u32 data_size, buf; u16 check; _enter(""); sp = rxrpc_skb(skb); /* we want to decrypt the skbuff in-place */ if (skb_cow_data(skb, 0, &trailer) < 0) goto nomem; skb_to_sgvec(skb, sg, 0, 8); /* start the decryption afresh */ memset(&iv, 0, sizeof(iv)); desc.tfm = call->conn->cipher; desc.info = iv.x; desc.flags = 0; crypto_blkcipher_decrypt_iv(&desc, sg, sg, 8); /* remove the decrypted packet length */ if (skb_copy_bits(skb, 0, &sechdr, sizeof(sechdr)) < 0) goto datalen_error; if (!skb_pull(skb, sizeof(sechdr))) BUG(); buf = ntohl(sechdr.data_size); data_size = buf & 0xffff; check = buf >> 16; check ^= ntohl(sp->hdr.seq ^ sp->hdr.callNumber); check &= 0xffff; if (check != 0) { *_abort_code = RXKADSEALEDINCON; goto protocol_error; } /* shorten the packet to remove the padding */ if (data_size > skb->len) goto datalen_error; else if (data_size < skb->len) skb->len = data_size; _leave(" = 0 [dlen=%x]", data_size); return 0; datalen_error: *_abort_code = RXKADDATALEN; protocol_error: _leave(" = -EPROTO"); return -EPROTO; nomem: _leave(" = -ENOMEM"); return -ENOMEM; } /* * wholly decrypt a packet (level 2 security) */ static int rxkad_verify_packet_encrypt(const struct rxrpc_call *call, struct sk_buff *skb, u32 *_abort_code) { const struct rxrpc_key_payload *payload; struct rxkad_level2_hdr sechdr; struct rxrpc_skb_priv *sp; struct blkcipher_desc desc; struct rxrpc_crypt iv; struct scatterlist _sg[4], *sg; struct sk_buff *trailer; u32 data_size, buf; u16 check; int nsg; _enter(",{%d}", skb->len); sp = rxrpc_skb(skb); /* we want to decrypt the skbuff in-place */ nsg = skb_cow_data(skb, 0, &trailer); if (nsg < 0) goto nomem; sg = _sg; if (unlikely(nsg > 4)) { sg = kmalloc(sizeof(*sg) * nsg, GFP_NOIO); if (!sg) goto nomem; } skb_to_sgvec(skb, sg, 0, skb->len); /* decrypt from the session key */ payload = call->conn->key->payload.data; memcpy(&iv, payload->k.session_key, sizeof(iv)); desc.tfm = call->conn->cipher; desc.info = iv.x; desc.flags = 0; crypto_blkcipher_decrypt_iv(&desc, sg, sg, skb->len); if (sg != _sg) kfree(sg); /* remove the decrypted packet length */ if (skb_copy_bits(skb, 0, &sechdr, sizeof(sechdr)) < 0) goto datalen_error; if (!skb_pull(skb, sizeof(sechdr))) BUG(); buf = ntohl(sechdr.data_size); data_size = buf & 0xffff; check = buf >> 16; check ^= ntohl(sp->hdr.seq ^ sp->hdr.callNumber); check &= 0xffff; if (check != 0) { *_abort_code = RXKADSEALEDINCON; goto protocol_error; } /* shorten the packet to remove the padding */ if (data_size > skb->len) goto datalen_error; else if (data_size < skb->len) skb->len = data_size; _leave(" = 0 [dlen=%x]", data_size); return 0; datalen_error: *_abort_code = RXKADDATALEN; protocol_error: _leave(" = -EPROTO"); return -EPROTO; nomem: _leave(" = -ENOMEM"); return -ENOMEM; } /* * verify the security on a received packet */ static int rxkad_verify_packet(const struct rxrpc_call *call, struct sk_buff *skb, u32 *_abort_code) { struct blkcipher_desc desc; struct rxrpc_skb_priv *sp; struct rxrpc_crypt iv; struct scatterlist sg[2]; struct { __be32 x[2]; } tmpbuf __attribute__((aligned(8))); /* must all be in same page */ __be32 x; __be16 cksum; int ret; sp = rxrpc_skb(skb); _enter("{%d{%x}},{#%u}", call->debug_id, key_serial(call->conn->key), ntohl(sp->hdr.seq)); if (!call->conn->cipher) return 0; if (sp->hdr.securityIndex != 2) { *_abort_code = RXKADINCONSISTENCY; _leave(" = -EPROTO [not rxkad]"); return -EPROTO; } /* continue encrypting from where we left off */ memcpy(&iv, call->conn->csum_iv.x, sizeof(iv)); desc.tfm = call->conn->cipher; desc.info = iv.x; desc.flags = 0; /* validate the security checksum */ x = htonl(call->channel << (32 - RXRPC_CIDSHIFT)); x |= sp->hdr.seq & __constant_cpu_to_be32(0x3fffffff); tmpbuf.x[0] = call->call_id; tmpbuf.x[1] = x; memset(&sg, 0, sizeof(sg)); sg_set_buf(&sg[0], &tmpbuf, sizeof(tmpbuf)); sg_set_buf(&sg[1], &tmpbuf, sizeof(tmpbuf)); crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf)); x = ntohl(tmpbuf.x[1]); x = (x >> 16) & 0xffff; if (x == 0) x = 1; /* zero checksums are not permitted */ cksum = htons(x); if (sp->hdr.cksum != cksum) { *_abort_code = RXKADSEALEDINCON; _leave(" = -EPROTO [csum failed]"); return -EPROTO; } switch (call->conn->security_level) { case RXRPC_SECURITY_PLAIN: ret = 0; break; case RXRPC_SECURITY_AUTH: ret = rxkad_verify_packet_auth(call, skb, _abort_code); break; case RXRPC_SECURITY_ENCRYPT: ret = rxkad_verify_packet_encrypt(call, skb, _abort_code); break; default: ret = -ENOANO; break; } _leave(" = %d", ret); return ret; } /* * issue a challenge */ static int rxkad_issue_challenge(struct rxrpc_connection *conn) { struct rxkad_challenge challenge; struct rxrpc_header hdr; struct msghdr msg; struct kvec iov[2]; size_t len; int ret; _enter("{%d,%x}", conn->debug_id, key_serial(conn->key)); ret = key_validate(conn->key); if (ret < 0) return ret; get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce)); challenge.version = htonl(2); challenge.nonce = htonl(conn->security_nonce); challenge.min_level = htonl(0); challenge.__padding = 0; msg.msg_name = &conn->trans->peer->srx.transport.sin; msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin); msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = 0; hdr.epoch = conn->epoch; hdr.cid = conn->cid; hdr.callNumber = 0; hdr.seq = 0; hdr.type = RXRPC_PACKET_TYPE_CHALLENGE; hdr.flags = conn->out_clientflag; hdr.userStatus = 0; hdr.securityIndex = conn->security_ix; hdr._rsvd = 0; hdr.serviceId = conn->service_id; iov[0].iov_base = &hdr; iov[0].iov_len = sizeof(hdr); iov[1].iov_base = &challenge; iov[1].iov_len = sizeof(challenge); len = iov[0].iov_len + iov[1].iov_len; hdr.serial = htonl(atomic_inc_return(&conn->serial)); _proto("Tx CHALLENGE %%%u", ntohl(hdr.serial)); ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len); if (ret < 0) { _debug("sendmsg failed: %d", ret); return -EAGAIN; } _leave(" = 0"); return 0; } /* * send a Kerberos security response */ static int rxkad_send_response(struct rxrpc_connection *conn, struct rxrpc_header *hdr, struct rxkad_response *resp, const struct rxkad_key *s2) { struct msghdr msg; struct kvec iov[3]; size_t len; int ret; _enter(""); msg.msg_name = &conn->trans->peer->srx.transport.sin; msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin); msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = 0; hdr->epoch = conn->epoch; hdr->seq = 0; hdr->type = RXRPC_PACKET_TYPE_RESPONSE; hdr->flags = conn->out_clientflag; hdr->userStatus = 0; hdr->_rsvd = 0; iov[0].iov_base = hdr; iov[0].iov_len = sizeof(*hdr); iov[1].iov_base = resp; iov[1].iov_len = sizeof(*resp); iov[2].iov_base = (void *) s2->ticket; iov[2].iov_len = s2->ticket_len; len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len; hdr->serial = htonl(atomic_inc_return(&conn->serial)); _proto("Tx RESPONSE %%%u", ntohl(hdr->serial)); ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 3, len); if (ret < 0) { _debug("sendmsg failed: %d", ret); return -EAGAIN; } _leave(" = 0"); return 0; } /* * calculate the response checksum */ static void rxkad_calc_response_checksum(struct rxkad_response *response) { u32 csum = 1000003; int loop; u8 *p = (u8 *) response; for (loop = sizeof(*response); loop > 0; loop--) csum = csum * 0x10204081 + *p++; response->encrypted.checksum = htonl(csum); } /* * load a scatterlist with a potentially split-page buffer */ static void rxkad_sg_set_buf2(struct scatterlist sg[2], void *buf, size_t buflen) { memset(sg, 0, sizeof(sg)); sg_set_buf(&sg[0], buf, buflen); if (sg[0].offset + buflen > PAGE_SIZE) { /* the buffer was split over two pages */ sg[0].length = PAGE_SIZE - sg[0].offset; sg_set_buf(&sg[1], buf + sg[0].length, buflen - sg[0].length); } ASSERTCMP(sg[0].length + sg[1].length, ==, buflen); } /* * encrypt the response packet */ static void rxkad_encrypt_response(struct rxrpc_connection *conn, struct rxkad_response *resp, const struct rxkad_key *s2) { struct blkcipher_desc desc; struct rxrpc_crypt iv; struct scatterlist ssg[2], dsg[2]; /* continue encrypting from where we left off */ memcpy(&iv, s2->session_key, sizeof(iv)); desc.tfm = conn->cipher; desc.info = iv.x; desc.flags = 0; rxkad_sg_set_buf2(ssg, &resp->encrypted, sizeof(resp->encrypted)); memcpy(dsg, ssg, sizeof(dsg)); crypto_blkcipher_encrypt_iv(&desc, dsg, ssg, sizeof(resp->encrypted)); } /* * respond to a challenge packet */ static int rxkad_respond_to_challenge(struct rxrpc_connection *conn, struct sk_buff *skb, u32 *_abort_code) { const struct rxrpc_key_payload *payload; struct rxkad_challenge challenge; struct rxkad_response resp __attribute__((aligned(8))); /* must be aligned for crypto */ struct rxrpc_skb_priv *sp; u32 version, nonce, min_level, abort_code; int ret; _enter("{%d,%x}", conn->debug_id, key_serial(conn->key)); if (!conn->key) { _leave(" = -EPROTO [no key]"); return -EPROTO; } ret = key_validate(conn->key); if (ret < 0) { *_abort_code = RXKADEXPIRED; return ret; } abort_code = RXKADPACKETSHORT; sp = rxrpc_skb(skb); if (skb_copy_bits(skb, 0, &challenge, sizeof(challenge)) < 0) goto protocol_error; version = ntohl(challenge.version); nonce = ntohl(challenge.nonce); min_level = ntohl(challenge.min_level); _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }", ntohl(sp->hdr.serial), version, nonce, min_level); abort_code = RXKADINCONSISTENCY; if (version != RXKAD_VERSION) goto protocol_error; abort_code = RXKADLEVELFAIL; if (conn->security_level < min_level) goto protocol_error; payload = conn->key->payload.data; /* build the response packet */ memset(&resp, 0, sizeof(resp)); resp.version = RXKAD_VERSION; resp.encrypted.epoch = conn->epoch; resp.encrypted.cid = conn->cid; resp.encrypted.securityIndex = htonl(conn->security_ix); resp.encrypted.call_id[0] = (conn->channels[0] ? conn->channels[0]->call_id : 0); resp.encrypted.call_id[1] = (conn->channels[1] ? conn->channels[1]->call_id : 0); resp.encrypted.call_id[2] = (conn->channels[2] ? conn->channels[2]->call_id : 0); resp.encrypted.call_id[3] = (conn->channels[3] ? conn->channels[3]->call_id : 0); resp.encrypted.inc_nonce = htonl(nonce + 1); resp.encrypted.level = htonl(conn->security_level); resp.kvno = htonl(payload->k.kvno); resp.ticket_len = htonl(payload->k.ticket_len); /* calculate the response checksum and then do the encryption */ rxkad_calc_response_checksum(&resp); rxkad_encrypt_response(conn, &resp, &payload->k); return rxkad_send_response(conn, &sp->hdr, &resp, &payload->k); protocol_error: *_abort_code = abort_code; _leave(" = -EPROTO [%d]", abort_code); return -EPROTO; } /* * decrypt the kerberos IV ticket in the response */ static int rxkad_decrypt_ticket(struct rxrpc_connection *conn, void *ticket, size_t ticket_len, struct rxrpc_crypt *_session_key, time_t *_expiry, u32 *_abort_code) { struct blkcipher_desc desc; struct rxrpc_crypt iv, key; struct scatterlist ssg[1], dsg[1]; struct in_addr addr; unsigned life; time_t issue, now; bool little_endian; int ret; u8 *p, *q, *name, *end; _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key)); *_expiry = 0; ret = key_validate(conn->server_key); if (ret < 0) { switch (ret) { case -EKEYEXPIRED: *_abort_code = RXKADEXPIRED; goto error; default: *_abort_code = RXKADNOAUTH; goto error; } } ASSERT(conn->server_key->payload.data != NULL); ASSERTCMP((unsigned long) ticket & 7UL, ==, 0); memcpy(&iv, &conn->server_key->type_data, sizeof(iv)); desc.tfm = conn->server_key->payload.data; desc.info = iv.x; desc.flags = 0; sg_init_one(&ssg[0], ticket, ticket_len); memcpy(dsg, ssg, sizeof(dsg)); crypto_blkcipher_decrypt_iv(&desc, dsg, ssg, ticket_len); p = ticket; end = p + ticket_len; #define Z(size) \ ({ \ u8 *__str = p; \ q = memchr(p, 0, end - p); \ if (!q || q - p > (size)) \ goto bad_ticket; \ for (; p < q; p++) \ if (!isprint(*p)) \ goto bad_ticket; \ p++; \ __str; \ }) /* extract the ticket flags */ _debug("KIV FLAGS: %x", *p); little_endian = *p & 1; p++; /* extract the authentication name */ name = Z(ANAME_SZ); _debug("KIV ANAME: %s", name); /* extract the principal's instance */ name = Z(INST_SZ); _debug("KIV INST : %s", name); /* extract the principal's authentication domain */ name = Z(REALM_SZ); _debug("KIV REALM: %s", name); if (end - p < 4 + 8 + 4 + 2) goto bad_ticket; /* get the IPv4 address of the entity that requested the ticket */ memcpy(&addr, p, sizeof(addr)); p += 4; _debug("KIV ADDR : "NIPQUAD_FMT, NIPQUAD(addr)); /* get the session key from the ticket */ memcpy(&key, p, sizeof(key)); p += 8; _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1])); memcpy(_session_key, &key, sizeof(key)); /* get the ticket's lifetime */ life = *p++ * 5 * 60; _debug("KIV LIFE : %u", life); /* get the issue time of the ticket */ if (little_endian) { __le32 stamp; memcpy(&stamp, p, 4); issue = le32_to_cpu(stamp); } else { __be32 stamp; memcpy(&stamp, p, 4); issue = be32_to_cpu(stamp); } p += 4; now = get_seconds(); _debug("KIV ISSUE: %lx [%lx]", issue, now); /* check the ticket is in date */ if (issue > now) { *_abort_code = RXKADNOAUTH; ret = -EKEYREJECTED; goto error; } if (issue < now - life) { *_abort_code = RXKADEXPIRED; ret = -EKEYEXPIRED; goto error; } *_expiry = issue + life; /* get the service name */ name = Z(SNAME_SZ); _debug("KIV SNAME: %s", name); /* get the service instance name */ name = Z(INST_SZ); _debug("KIV SINST: %s", name); ret = 0; error: _leave(" = %d", ret); return ret; bad_ticket: *_abort_code = RXKADBADTICKET; ret = -EBADMSG; goto error; } /* * decrypt the response packet */ static void rxkad_decrypt_response(struct rxrpc_connection *conn, struct rxkad_response *resp, const struct rxrpc_crypt *session_key) { struct blkcipher_desc desc; struct scatterlist ssg[2], dsg[2]; struct rxrpc_crypt iv; _enter(",,%08x%08x", ntohl(session_key->n[0]), ntohl(session_key->n[1])); ASSERT(rxkad_ci != NULL); mutex_lock(&rxkad_ci_mutex); if (crypto_blkcipher_setkey(rxkad_ci, session_key->x, sizeof(*session_key)) < 0) BUG(); memcpy(&iv, session_key, sizeof(iv)); desc.tfm = rxkad_ci; desc.info = iv.x; desc.flags = 0; rxkad_sg_set_buf2(ssg, &resp->encrypted, sizeof(resp->encrypted)); memcpy(dsg, ssg, sizeof(dsg)); crypto_blkcipher_decrypt_iv(&desc, dsg, ssg, sizeof(resp->encrypted)); mutex_unlock(&rxkad_ci_mutex); _leave(""); } /* * verify a response */ static int rxkad_verify_response(struct rxrpc_connection *conn, struct sk_buff *skb, u32 *_abort_code) { struct rxkad_response response __attribute__((aligned(8))); /* must be aligned for crypto */ struct rxrpc_skb_priv *sp; struct rxrpc_crypt session_key; time_t expiry; void *ticket; u32 abort_code, version, kvno, ticket_len, csum, level; int ret; _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key)); abort_code = RXKADPACKETSHORT; if (skb_copy_bits(skb, 0, &response, sizeof(response)) < 0) goto protocol_error; if (!pskb_pull(skb, sizeof(response))) BUG(); version = ntohl(response.version); ticket_len = ntohl(response.ticket_len); kvno = ntohl(response.kvno); sp = rxrpc_skb(skb); _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }", ntohl(sp->hdr.serial), version, kvno, ticket_len); abort_code = RXKADINCONSISTENCY; if (version != RXKAD_VERSION) abort_code = RXKADTICKETLEN; if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN) goto protocol_error; abort_code = RXKADUNKNOWNKEY; if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5) goto protocol_error; /* extract the kerberos ticket and decrypt and decode it */ ticket = kmalloc(ticket_len, GFP_NOFS); if (!ticket) return -ENOMEM; abort_code = RXKADPACKETSHORT; if (skb_copy_bits(skb, 0, ticket, ticket_len) < 0) goto protocol_error_free; ret = rxkad_decrypt_ticket(conn, ticket, ticket_len, &session_key, &expiry, &abort_code); if (ret < 0) { *_abort_code = abort_code; kfree(ticket); return ret; } /* use the session key from inside the ticket to decrypt the * response */ rxkad_decrypt_response(conn, &response, &session_key); abort_code = RXKADSEALEDINCON; if (response.encrypted.epoch != conn->epoch) goto protocol_error_free; if (response.encrypted.cid != conn->cid) goto protocol_error_free; if (ntohl(response.encrypted.securityIndex) != conn->security_ix) goto protocol_error_free; csum = response.encrypted.checksum; response.encrypted.checksum = 0; rxkad_calc_response_checksum(&response); if (response.encrypted.checksum != csum) goto protocol_error_free; if (ntohl(response.encrypted.call_id[0]) > INT_MAX || ntohl(response.encrypted.call_id[1]) > INT_MAX || ntohl(response.encrypted.call_id[2]) > INT_MAX || ntohl(response.encrypted.call_id[3]) > INT_MAX) goto protocol_error_free; abort_code = RXKADOUTOFSEQUENCE; if (response.encrypted.inc_nonce != htonl(conn->security_nonce + 1)) goto protocol_error_free; abort_code = RXKADLEVELFAIL; level = ntohl(response.encrypted.level); if (level > RXRPC_SECURITY_ENCRYPT) goto protocol_error_free; conn->security_level = level; /* create a key to hold the security data and expiration time - after * this the connection security can be handled in exactly the same way * as for a client connection */ ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno); if (ret < 0) { kfree(ticket); return ret; } kfree(ticket); _leave(" = 0"); return 0; protocol_error_free: kfree(ticket); protocol_error: *_abort_code = abort_code; _leave(" = -EPROTO [%d]", abort_code); return -EPROTO; } /* * clear the connection security */ static void rxkad_clear(struct rxrpc_connection *conn) { _enter(""); if (conn->cipher) crypto_free_blkcipher(conn->cipher); } /* * RxRPC Kerberos-based security */ static struct rxrpc_security rxkad = { .owner = THIS_MODULE, .name = "rxkad", .security_index = RXKAD_VERSION, .init_connection_security = rxkad_init_connection_security, .prime_packet_security = rxkad_prime_packet_security, .secure_packet = rxkad_secure_packet, .verify_packet = rxkad_verify_packet, .issue_challenge = rxkad_issue_challenge, .respond_to_challenge = rxkad_respond_to_challenge, .verify_response = rxkad_verify_response, .clear = rxkad_clear, }; static __init int rxkad_init(void) { _enter(""); /* pin the cipher we need so that the crypto layer doesn't invoke * keventd to go get it */ rxkad_ci = crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC); if (IS_ERR(rxkad_ci)) return PTR_ERR(rxkad_ci); return rxrpc_register_security(&rxkad); } module_init(rxkad_init); static __exit void rxkad_exit(void) { _enter(""); rxrpc_unregister_security(&rxkad); crypto_free_blkcipher(rxkad_ci); } module_exit(rxkad_exit);


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