From 07ff2dd510d8c5b1166827df7686036283be10e0 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 3 Aug 2017 14:30:19 -0400 Subject: xprtrdma: Refactor rpcrdma_reply_handler() Refactor the reply handler's transport header decoding logic to make it easier to understand and update. Convert some of the handler to use xdr_streams, which will enable stricter validation of input data and enable the eventual addition of support for new combinations of chunks, such as "Write + Reply" or "PZRC + normal Read". Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/rpc_rdma.c | 212 +++++++++++++++++++++++++---------------- 1 file changed, 130 insertions(+), 82 deletions(-) (limited to 'net/sunrpc') diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c index 9b5ab598ab7b..56f22773fa4b 100644 --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -1004,6 +1004,124 @@ out_short: } #endif /* CONFIG_SUNRPC_BACKCHANNEL */ +static int +rpcrdma_decode_msg(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep, + struct rpc_rqst *rqst) +{ + struct xdr_stream *xdr = &rep->rr_stream; + int rdmalen, status; + __be32 *p; + + p = xdr_inline_decode(xdr, 2 * sizeof(*p)); + if (unlikely(!p)) + return -EIO; + + /* never expect read list */ + if (unlikely(*p++ != xdr_zero)) + return -EIO; + + /* Write list */ + if (*p != xdr_zero) { + char *base = rep->rr_hdrbuf.head[0].iov_base; + + p++; + rdmalen = rpcrdma_count_chunks(rep, 1, &p); + if (rdmalen < 0 || *p++ != xdr_zero) + return -EIO; + + rep->rr_len -= (char *)p - base; + status = rep->rr_len + rdmalen; + r_xprt->rx_stats.total_rdma_reply += rdmalen; + + /* special case - last segment may omit padding */ + rdmalen &= 3; + if (rdmalen) { + rdmalen = 4 - rdmalen; + status += rdmalen; + } + } else { + p = xdr_inline_decode(xdr, sizeof(*p)); + if (!p) + return -EIO; + + /* never expect reply chunk */ + if (*p++ != xdr_zero) + return -EIO; + rdmalen = 0; + rep->rr_len -= RPCRDMA_HDRLEN_MIN; + status = rep->rr_len; + } + + r_xprt->rx_stats.fixup_copy_count += + rpcrdma_inline_fixup(rqst, (char *)p, rep->rr_len, + rdmalen); + + return status; +} + +static noinline int +rpcrdma_decode_nomsg(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep) +{ + struct xdr_stream *xdr = &rep->rr_stream; + int rdmalen; + __be32 *p; + + p = xdr_inline_decode(xdr, 3 * sizeof(*p)); + if (unlikely(!p)) + return -EIO; + + /* never expect Read chunks */ + if (unlikely(*p++ != xdr_zero)) + return -EIO; + /* never expect Write chunks */ + if (unlikely(*p++ != xdr_zero)) + return -EIO; + /* always expect a Reply chunk */ + if (unlikely(*p++ == xdr_zero)) + return -EIO; + + rdmalen = rpcrdma_count_chunks(rep, 0, &p); + if (rdmalen < 0) + return -EIO; + r_xprt->rx_stats.total_rdma_reply += rdmalen; + + /* Reply chunk buffer already is the reply vector - no fixup. */ + return rdmalen; +} + +static noinline int +rpcrdma_decode_error(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep, + struct rpc_rqst *rqst) +{ + struct xdr_stream *xdr = &rep->rr_stream; + __be32 *p; + + p = xdr_inline_decode(xdr, sizeof(*p)); + if (unlikely(!p)) + return -EIO; + + switch (*p) { + case err_vers: + p = xdr_inline_decode(xdr, 2 * sizeof(*p)); + if (!p) + break; + dprintk("RPC: %5u: %s: server reports version error (%u-%u)\n", + rqst->rq_task->tk_pid, __func__, + be32_to_cpup(p), be32_to_cpu(*(p + 1))); + break; + case err_chunk: + dprintk("RPC: %5u: %s: server reports header decoding error\n", + rqst->rq_task->tk_pid, __func__); + break; + default: + dprintk("RPC: %5u: %s: server reports unrecognized error %d\n", + rqst->rq_task->tk_pid, __func__, be32_to_cpup(p)); + } + + r_xprt->rx_stats.bad_reply_count++; + return -EREMOTEIO; +} + /* Process received RPC/RDMA messages. * * Errors must result in the RPC task either being awakened, or @@ -1018,13 +1136,12 @@ rpcrdma_reply_handler(struct work_struct *work) struct rpcrdma_buffer *buf = &r_xprt->rx_buf; struct rpc_xprt *xprt = &r_xprt->rx_xprt; struct xdr_stream *xdr = &rep->rr_stream; - struct rpcrdma_msg *headerp; struct rpcrdma_req *req; struct rpc_rqst *rqst; - __be32 *iptr, *p, xid, vers, proc; - int rdmalen, status, rmerr; + __be32 *p, xid, vers, proc; unsigned long cwnd; struct list_head mws; + int status; dprintk("RPC: %s: incoming rep %p\n", __func__, rep); @@ -1043,7 +1160,6 @@ rpcrdma_reply_handler(struct work_struct *work) p++; /* credits */ proc = *p++; - headerp = rdmab_to_msg(rep->rr_rdmabuf); if (rpcrdma_is_bcall(r_xprt, rep, xid, proc)) return; @@ -1091,75 +1207,21 @@ rpcrdma_reply_handler(struct work_struct *work) if (vers != rpcrdma_version) goto out_badversion; - /* check for expected message types */ - /* The order of some of these tests is important. */ switch (proc) { case rdma_msg: - /* never expect read chunks */ - /* never expect reply chunks (two ways to check) */ - if (headerp->rm_body.rm_chunks[0] != xdr_zero || - (headerp->rm_body.rm_chunks[1] == xdr_zero && - headerp->rm_body.rm_chunks[2] != xdr_zero)) - goto badheader; - if (headerp->rm_body.rm_chunks[1] != xdr_zero) { - /* count any expected write chunks in read reply */ - /* start at write chunk array count */ - iptr = &headerp->rm_body.rm_chunks[2]; - rdmalen = rpcrdma_count_chunks(rep, 1, &iptr); - /* check for validity, and no reply chunk after */ - if (rdmalen < 0 || *iptr++ != xdr_zero) - goto badheader; - rep->rr_len -= - ((unsigned char *)iptr - (unsigned char *)headerp); - status = rep->rr_len + rdmalen; - r_xprt->rx_stats.total_rdma_reply += rdmalen; - /* special case - last chunk may omit padding */ - if (rdmalen &= 3) { - rdmalen = 4 - rdmalen; - status += rdmalen; - } - } else { - /* else ordinary inline */ - rdmalen = 0; - iptr = (__be32 *)((unsigned char *)headerp + - RPCRDMA_HDRLEN_MIN); - rep->rr_len -= RPCRDMA_HDRLEN_MIN; - status = rep->rr_len; - } - - r_xprt->rx_stats.fixup_copy_count += - rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len, - rdmalen); + status = rpcrdma_decode_msg(r_xprt, rep, rqst); break; - case rdma_nomsg: - /* never expect read or write chunks, always reply chunks */ - if (headerp->rm_body.rm_chunks[0] != xdr_zero || - headerp->rm_body.rm_chunks[1] != xdr_zero || - headerp->rm_body.rm_chunks[2] != xdr_one) - goto badheader; - iptr = (__be32 *)((unsigned char *)headerp + - RPCRDMA_HDRLEN_MIN); - rdmalen = rpcrdma_count_chunks(rep, 0, &iptr); - if (rdmalen < 0) - goto badheader; - r_xprt->rx_stats.total_rdma_reply += rdmalen; - /* Reply chunk buffer already is the reply vector - no fixup. */ - status = rdmalen; + status = rpcrdma_decode_nomsg(r_xprt, rep); break; - case rdma_error: - goto out_rdmaerr; - -badheader: + status = rpcrdma_decode_error(r_xprt, rep, rqst); + break; default: - dprintk("RPC: %5u %s: invalid rpcrdma reply (type %u)\n", - rqst->rq_task->tk_pid, __func__, - be32_to_cpu(proc)); status = -EIO; - r_xprt->rx_stats.bad_reply_count++; - break; } + if (status < 0) + goto out_badheader; out: cwnd = xprt->cwnd; @@ -1192,25 +1254,11 @@ out_badversion: r_xprt->rx_stats.bad_reply_count++; goto out; -out_rdmaerr: - rmerr = be32_to_cpu(headerp->rm_body.rm_error.rm_err); - switch (rmerr) { - case ERR_VERS: - pr_err("%s: server reports header version error (%u-%u)\n", - __func__, - be32_to_cpu(headerp->rm_body.rm_error.rm_vers_low), - be32_to_cpu(headerp->rm_body.rm_error.rm_vers_high)); - break; - case ERR_CHUNK: - pr_err("%s: server reports header decoding error\n", - __func__); - break; - default: - pr_err("%s: server reports unknown error %d\n", - __func__, rmerr); - } - status = -EREMOTEIO; +out_badheader: + dprintk("RPC: %5u %s: invalid rpcrdma reply (type %u)\n", + rqst->rq_task->tk_pid, __func__, be32_to_cpu(proc)); r_xprt->rx_stats.bad_reply_count++; + status = -EIO; goto out; /* The req was still available, but by the time the transport_lock -- cgit v1.2.3