SUNRPC: Augment server-side rpcgss tracepoints

Add similar tracepoints to those that were recently added on the
client side to track failures in the integ and priv unwrap paths.

And, let's collect the seqno-specific tracepoints together with a
common naming convention.

Regarding the gss_check_seq_num() changes: everywhere else treats
the GSS sequence number as an unsigned 32-bit integer. As far back
as 2.6.12, I couldn't find a compelling reason to do things
differently here. As a defensive change it's better to eliminate
needless implicit sign conversions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

2 files changed, 82 insertions, 38 deletions

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 46027d0c903f..7d83f54aaaa6 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -332,7 +332,7 @@ static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct r
 
 struct gss_svc_seq_data {
 	/* highest seq number seen so far: */
-	int			sd_max;
+	u32			sd_max;
 	/* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of
 	 * sd_win is nonzero iff sequence number i has been seen already: */
 	unsigned long		sd_win[GSS_SEQ_WIN/BITS_PER_LONG];
@@ -613,16 +613,29 @@ gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
 	return found;
 }
 
-/* Implements sequence number algorithm as specified in RFC 2203. */
-static int
-gss_check_seq_num(struct rsc *rsci, int seq_num)
+/**
+ * gss_check_seq_num - GSS sequence number window check
+ * @rqstp: RPC Call to use when reporting errors
+ * @rsci: cached GSS context state (updated on return)
+ * @seq_num: sequence number to check
+ *
+ * Implements sequence number algorithm as specified in
+ * RFC 2203, Section 5.3.3.1. "Context Management".
+ *
+ * Return values:
+ *   %true: @rqstp's GSS sequence number is inside the window
+ *   %false: @rqstp's GSS sequence number is outside the window
+ */
+static bool gss_check_seq_num(const struct svc_rqst *rqstp, struct rsc *rsci,
+			      u32 seq_num)
 {
 	struct gss_svc_seq_data *sd = &rsci->seqdata;
+	bool result = false;
 
 	spin_lock(&sd->sd_lock);
 	if (seq_num > sd->sd_max) {
 		if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
-			memset(sd->sd_win,0,sizeof(sd->sd_win));
+			memset(sd->sd_win, 0, sizeof(sd->sd_win));
 			sd->sd_max = seq_num;
 		} else while (sd->sd_max < seq_num) {
 			sd->sd_max++;
@@ -631,17 +644,25 @@ gss_check_seq_num(struct rsc *rsci, int seq_num)
 		__set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
 		goto ok;
 	} else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
-		goto drop;
+		goto toolow;
 	}
-	/* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
 	if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
-		goto drop;
+		goto alreadyseen;
+
 ok:
+	result = true;
+out:
 	spin_unlock(&sd->sd_lock);
-	return 1;
-drop:
-	spin_unlock(&sd->sd_lock);
-	return 0;
+	return result;
+
+toolow:
+	trace_rpcgss_svc_seqno_low(rqstp, seq_num,
+				   sd->sd_max - GSS_SEQ_WIN,
+				   sd->sd_max);
+	goto out;
+alreadyseen:
+	trace_rpcgss_svc_seqno_seen(rqstp, seq_num);
+	goto out;
 }
 
 static inline u32 round_up_to_quad(u32 i)
@@ -721,14 +742,12 @@ gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
 	}
 
 	if (gc->gc_seq > MAXSEQ) {
-		trace_rpcgss_svc_large_seqno(rqstp->rq_xid, gc->gc_seq);
+		trace_rpcgss_svc_seqno_large(rqstp, gc->gc_seq);
 		*authp = rpcsec_gsserr_ctxproblem;
 		return SVC_DENIED;
 	}
-	if (!gss_check_seq_num(rsci, gc->gc_seq)) {
-		trace_rpcgss_svc_old_seqno(rqstp->rq_xid, gc->gc_seq);
+	if (!gss_check_seq_num(rqstp, rsci, gc->gc_seq))
 		return SVC_DROP;
-	}
 	return SVC_OK;
 }
 
@@ -866,11 +885,13 @@ read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
 static int
 unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
 {
+	u32 integ_len, rseqno, maj_stat;
 	int stat = -EINVAL;
-	u32 integ_len, maj_stat;
 	struct xdr_netobj mic;
 	struct xdr_buf integ_buf;
 
+	mic.data = NULL;
+
 	/* NFS READ normally uses splice to send data in-place. However
 	 * the data in cache can change after the reply's MIC is computed
 	 * but before the RPC reply is sent. To prevent the client from
@@ -885,34 +906,44 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct g
 
 	integ_len = svc_getnl(&buf->head[0]);
 	if (integ_len & 3)
-		return stat;
+		goto unwrap_failed;
 	if (integ_len > buf->len)
-		return stat;
-	if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len)) {
-		WARN_ON_ONCE(1);
-		return stat;
-	}
+		goto unwrap_failed;
+	if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
+		goto unwrap_failed;
+
 	/* copy out mic... */
 	if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
-		return stat;
+		goto unwrap_failed;
 	if (mic.len > RPC_MAX_AUTH_SIZE)
-		return stat;
+		goto unwrap_failed;
 	mic.data = kmalloc(mic.len, GFP_KERNEL);
 	if (!mic.data)
-		return stat;
+		goto unwrap_failed;
 	if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
-		goto out;
+		goto unwrap_failed;
 	maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
 	if (maj_stat != GSS_S_COMPLETE)
-		goto out;
-	if (svc_getnl(&buf->head[0]) != seq)
-		goto out;
+		goto bad_mic;
+	rseqno = svc_getnl(&buf->head[0]);
+	if (rseqno != seq)
+		goto bad_seqno;
 	/* trim off the mic and padding at the end before returning */
 	xdr_buf_trim(buf, round_up_to_quad(mic.len) + 4);
 	stat = 0;
 out:
 	kfree(mic.data);
 	return stat;
+
+unwrap_failed:
+	trace_rpcgss_svc_unwrap_failed(rqstp);
+	goto out;
+bad_seqno:
+	trace_rpcgss_svc_seqno_bad(rqstp, seq, rseqno);
+	goto out;
+bad_mic:
+	trace_rpcgss_svc_mic(rqstp, maj_stat);
+	goto out;
 }
 
 static inline int
@@ -937,6 +968,7 @@ unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gs
 {
 	u32 priv_len, maj_stat;
 	int pad, remaining_len, offset;
+	u32 rseqno;
 
 	clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 
@@ -951,7 +983,7 @@ unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gs
 	 * not yet read from the head, so these two values are different: */
 	remaining_len = total_buf_len(buf);
 	if (priv_len > remaining_len)
-		return -EINVAL;
+		goto unwrap_failed;
 	pad = remaining_len - priv_len;
 	buf->len -= pad;
 	fix_priv_head(buf, pad);
@@ -972,11 +1004,22 @@ unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gs
 		fix_priv_head(buf, pad);
 	}
 	if (maj_stat != GSS_S_COMPLETE)
-		return -EINVAL;
+		goto bad_unwrap;
 out_seq:
-	if (svc_getnl(&buf->head[0]) != seq)
-		return -EINVAL;
+	rseqno = svc_getnl(&buf->head[0]);
+	if (rseqno != seq)
+		goto bad_seqno;
 	return 0;
+
+unwrap_failed:
+	trace_rpcgss_svc_unwrap_failed(rqstp);
+	return -EINVAL;
+bad_seqno:
+	trace_rpcgss_svc_seqno_bad(rqstp, seq, rseqno);
+	return -EINVAL;
+bad_unwrap:
+	trace_rpcgss_svc_unwrap(rqstp, maj_stat);
+	return -EINVAL;
 }
 
 struct gss_svc_data {
@@ -1314,8 +1357,7 @@ static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
 	if (status)
 		goto out;
 
-	trace_rpcgss_svc_accept_upcall(rqstp->rq_xid, ud.major_status,
-				       ud.minor_status);
+	trace_rpcgss_svc_accept_upcall(rqstp, ud.major_status, ud.minor_status);
 
 	switch (ud.major_status) {
 	case GSS_S_CONTINUE_NEEDED:
@@ -1490,8 +1532,6 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 	int		ret;
 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
 
-	trace_rpcgss_svc_accept(rqstp->rq_xid, argv->iov_len);
-
 	*authp = rpc_autherr_badcred;
 	if (!svcdata)
 		svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
@@ -1608,6 +1648,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
 					GSS_C_QOP_DEFAULT,
 					gc->gc_svc);
 		ret = SVC_OK;
+		trace_rpcgss_svc_authenticate(rqstp, gc);
 		goto out;
 	}
 garbage_args:
diff --git a/net/sunrpc/auth_gss/trace.c b/net/sunrpc/auth_gss/trace.c
index 49fa583d7f91..d26036a57443 100644
--- a/net/sunrpc/auth_gss/trace.c
+++ b/net/sunrpc/auth_gss/trace.c
@@ -5,6 +5,9 @@
 
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/sunrpc/auth_gss.h>
 #include <linux/sunrpc/gss_err.h>
 #include <linux/sunrpc/auth_gss.h>