[PATCH 01/16] libfc: recode incoming PRLI handling

Robert Love
2010-03-13T00:07:37Z

Reduce indentation in fc_rport_recv_prli_req() using gotos.
Also add payload length checks.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
---

drivers/scsi/libfc/fc_rport.c | 195 ++++++++++++++++++-----------------------
1 files changed, 87 insertions(+), 108 deletions(-)

diff --git a/drivers/scsi/libfc/fc_rport.c b/drivers/scsi/libfc/fc_rport.c
index 97923bb..09ec635 100644
--- a/drivers/scsi/libfc/fc_rport.c
+++ b/drivers/scsi/libfc/fc_rport.c
@@ -1441,136 +1441,115 @@ static void fc_rport_recv_prli_req(struct fc_rport_priv *rdata,
struct fc_els_spp *spp; /* response spp */
unsigned int len;
unsigned int plen;
- enum fc_els_rjt_reason reason = ELS_RJT_UNAB;
- enum fc_els_rjt_explan explan = ELS_EXPL_NONE;
enum fc_els_spp_resp resp;
struct fc_seq_els_data rjt_data;
u32 f_ctl;
u32 fcp_parm;
u32 roles = FC_RPORT_ROLE_UNKNOWN;
- rjt_data.fp = NULL;

+ rjt_data.fp = NULL;
fh = fc_frame_header_get(rx_fp);

FC_RPORT_DBG(rdata, "Received PRLI request while in state %s\n",
fc_rport_state(rdata));

- switch (rdata->rp_state) {
- case RPORT_ST_PRLI:
- case RPORT_ST_RTV:
- case RPORT_ST_READY:
- case RPORT_ST_ADISC:
- reason = ELS_RJT_NONE;
- break;
- default:
- fc_frame_free(rx_fp);
- return;
- break;
- }
len = fr_len(rx_fp) - sizeof(*fh);
pp = fc_frame_payload_get(rx_fp, sizeof(*pp));
- if (pp == NULL) {
- reason = ELS_RJT_PROT;
- explan = ELS_EXPL_INV_LEN;
- } else {
- plen = ntohs(pp->prli.prli_len);
- if ((plen % 4) != 0 || plen > len) {
- reason = ELS_RJT_PROT;
- explan = ELS_EXPL_INV_LEN;
- } else if (plen < len) {
- len = plen;
- }
- plen = pp->prli.prli_spp_len;
- if ((plen % 4) != 0 || plen < sizeof(*spp) ||
- plen > len || len < sizeof(*pp)) {
- reason = ELS_RJT_PROT;
- explan = ELS_EXPL_INV_LEN;
- }
- rspp = &pp->spp;
+ if (!pp)
+ goto reject_len;
+ plen = ntohs(pp->prli.prli_len);
+ if ((plen % 4) != 0 || plen > len || plen < 16)
+ goto reject_len;
+ if (plen < len)
+ len = plen;
+ plen = pp->prli.prli_spp_len;
+ if ((plen % 4) != 0 || plen < sizeof(*spp) ||
+ plen > len || len < sizeof(*pp) || plen < 12)
+ goto reject_len;
+ rspp = &pp->spp;
+
+ fp = fc_frame_alloc(lport, len);
+ if (!fp) {
+ rjt_data.reason = ELS_RJT_UNAB;
+ rjt_data.explan = ELS_EXPL_INSUF_RES;
+ goto reject;
}
- if (reason != ELS_RJT_NONE ||
- (fp = fc_frame_alloc(lport, len)) == NULL) {
- rjt_data.reason = reason;
- rjt_data.explan = explan;
- lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
- } else {
- sp = lport->tt.seq_start_next(sp);
- WARN_ON(!sp);
- pp = fc_frame_payload_get(fp, len);
- WARN_ON(!pp);
- memset(pp, 0, len);
- pp->prli.prli_cmd = ELS_LS_ACC;
- pp->prli.prli_spp_len = plen;
- pp->prli.prli_len = htons(len);
- len -= sizeof(struct fc_els_prli);
-
- /* reinitialize remote port roles */
- rdata->ids.roles = FC_RPORT_ROLE_UNKNOWN;
-
- /*
- * Go through all the service parameter pages and build
- * response. If plen indicates longer SPP than standard,
- * use that. The entire response has been pre-cleared above.
- */
- spp = &pp->spp;
- while (len >= plen) {
- spp->spp_type = rspp->spp_type;
- spp->spp_type_ext = rspp->spp_type_ext;
- spp->spp_flags = rspp->spp_flags & FC_SPP_EST_IMG_PAIR;
- resp = FC_SPP_RESP_ACK;
- if (rspp->spp_flags & FC_SPP_RPA_VAL)
- resp = FC_SPP_RESP_NO_PA;
- switch (rspp->spp_type) {
- case 0: /* common to all FC-4 types */
- break;
- case FC_TYPE_FCP:
- fcp_parm = ntohl(rspp->spp_params);
- if (fcp_parm & FCP_SPPF_RETRY)
- rdata->flags |= FC_RP_FLAGS_RETRY;
- rdata->supported_classes = FC_COS_CLASS3;
- if (fcp_parm & FCP_SPPF_INIT_FCN)
- roles |= FC_RPORT_ROLE_FCP_INITIATOR;
- if (fcp_parm & FCP_SPPF_TARG_FCN)
- roles |= FC_RPORT_ROLE_FCP_TARGET;
- rdata->ids.roles = roles;
-
- spp->spp_params =
- htonl(lport->service_params);
- break;
- default:
- resp = FC_SPP_RESP_INVL;
- break;
- }
- spp->spp_flags |= resp;
- len -= plen;
- rspp = (struct fc_els_spp *)((char *)rspp + plen);
- spp = (struct fc_els_spp *)((char *)spp + plen);
- }
+ sp = lport->tt.seq_start_next(sp);
+ WARN_ON(!sp);
+ pp = fc_frame_payload_get(fp, len);
+ WARN_ON(!pp);
+ memset(pp, 0, len);
+ pp->prli.prli_cmd = ELS_LS_ACC;
+ pp->prli.prli_spp_len = plen;
+ pp->prli.prli_len = htons(len);
+ len -= sizeof(struct fc_els_prli);

- /*
- * Send LS_ACC. If this fails, the originator should retry.
- */
- f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ;
- f_ctl |= FC_FC_END_SEQ | FC_FC_SEQ_INIT;
- ep = fc_seq_exch(sp);
- fc_fill_fc_hdr(fp, FC_RCTL_ELS_REP, ep->did, ep->sid,
- FC_TYPE_ELS, f_ctl, 0);
- lport->tt.seq_send(lport, sp, fp);
+ /* reinitialize remote port roles */
+ rdata->ids.roles = FC_RPORT_ROLE_UNKNOWN;

- /*
- * Get lock and re-check state.
- */
- switch (rdata->rp_state) {
- case RPORT_ST_PRLI:
- fc_rport_enter_ready(rdata);
+ /*
+ * Go through all the service parameter pages and build
+ * response. If plen indicates longer SPP than standard,
+ * use that. The entire response has been pre-cleared above.
+ */
+ spp = &pp->spp;
+ while (len >= plen) {
+ spp->spp_type = rspp->spp_type;
+ spp->spp_type_ext = rspp->spp_type_ext;
+ spp->spp_flags = rspp->spp_flags & FC_SPP_EST_IMG_PAIR;
+ resp = FC_SPP_RESP_ACK;
+
+ switch (rspp->spp_type) {
+ case 0: /* common to all FC-4 types */
break;
- case RPORT_ST_READY:
- case RPORT_ST_ADISC:
+ case FC_TYPE_FCP:
+ fcp_parm = ntohl(rspp->spp_params);
+ if (fcp_parm & FCP_SPPF_RETRY)
+ rdata->flags |= FC_RP_FLAGS_RETRY;
+ rdata->supported_classes = FC_COS_CLASS3;
+ if (fcp_parm & FCP_SPPF_INIT_FCN)
+ roles |= FC_RPORT_ROLE_FCP_INITIATOR;
+ if (fcp_parm & FCP_SPPF_TARG_FCN)
+ roles |= FC_RPORT_ROLE_FCP_TARGET;
+ rdata->ids.roles = roles;
+
+ spp->spp_params = htonl(lport->service_params);
break;
default:
+ resp = FC_SPP_RESP_INVL;
break;
}
+ spp->spp_flags |= resp;
+ len -= plen;
+ rspp = (struct fc_els_spp *)((char *)rspp + plen);
+ spp = (struct fc_els_spp *)((char *)spp + plen);
+ }
+
+ /*
+ * Send LS_ACC. If this fails, the originator should retry.
+ */
+ f_ctl = FC_FC_EX_CTX | FC_FC_LAST_SEQ;
+ f_ctl |= FC_FC_END_SEQ | FC_FC_SEQ_INIT;
+ ep = fc_seq_exch(sp);
+ fc_fill_fc_hdr(fp, FC_RCTL_ELS_REP, ep->did, ep->sid,
+ FC_TYPE_ELS, f_ctl, 0);
+ lport->tt.seq_send(lport, sp, fp);
+
+ switch (rdata->rp_state) {
+ case RPORT_ST_PRLI:
+ fc_rport_enter_ready(rdata);
+ break;
+ default:
+ break;
}
+ goto drop;
+
+reject_len:
+ rjt_data.reason = ELS_RJT_PROT;
+ rjt_data.explan = ELS_EXPL_INV_LEN;
+reject:
+ lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
+drop:
fc_frame_free(rx_fp);
}