autopath: Create the autopath action.

[sliver-openvswitch.git] / lib / autopath.c

diff --git a/lib/autopath.c b/lib/autopath.c
new file mode 100644 (file)
index 0000000..889b037
--- /dev/null
+++ b/lib/autopath.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2011 Nicira Networks.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include "autopath.h"
+
+#include <inttypes.h>
+#include <stdlib.h>
+
+#include "flow.h"
+#include "nx-match.h"
+#include "ofp-util.h"
+#include "openflow/nicira-ext.h"
+#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(autopath);
+
+static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+
+/* Loads 'ofp_port' into the appropriate register in accordance with the
+ * autopath action. */
+void
+autopath_execute(const struct nx_action_autopath *ap, struct flow *flow,
+                 uint16_t ofp_port)
+{
+    uint32_t *reg = &flow->regs[NXM_NX_REG_IDX(ntohl(ap->dst))];
+    int ofs = nxm_decode_ofs(ap->ofs_nbits);
+    int n_bits = nxm_decode_n_bits(ap->ofs_nbits);
+    uint32_t mask = n_bits == 32 ? UINT32_MAX : (UINT32_C(1) << n_bits) - 1;
+    *reg = (*reg & ~(mask << ofs)) | ((ofp_port & mask) << ofs);
+}
+
+void
+autopath_parse(struct nx_action_autopath *ap, const char *s_)
+{
+    char *s;
+    uint32_t reg;
+    int id_int, ofs, n_bits;
+    char *id_str, *dst, *save_ptr;
+
+    s = xstrdup(s_);
+    save_ptr = NULL;
+    id_str = strtok_r(s, ", ", &save_ptr);
+    dst = strtok_r(NULL, ", ", &save_ptr);
+
+    if (!dst) {
+        ovs_fatal(0, "%s: not enough arguments to autopath action", s_);
+    }
+
+    id_int = atoi(id_str);
+    if (id_int < 1 || id_int > UINT32_MAX) {
+        ovs_fatal(0, "%s: autopath id %d is not in valid range "
+                  "1 to %"PRIu32, s_, id_int, UINT32_MAX);
+    }
+
+    nxm_parse_field_bits(dst, &reg, &ofs, &n_bits);
+    if (!NXM_IS_NX_REG(reg) || NXM_NX_REG_IDX(reg) >= FLOW_N_REGS) {
+        ovs_fatal(0, "%s: destination field must be a register", s_);
+    }
+
+    if (n_bits < 16) {
+        ovs_fatal(0, "%s: %d-bit destination field has %u possible values, "
+                  "less than required 65536", s_, n_bits, 1u << n_bits);
+    }
+
+    memset(ap, 0, sizeof *ap);
+    ap->type = htons(OFPAT_VENDOR);
+    ap->len = htons(sizeof *ap);
+    ap->vendor = htonl(NX_VENDOR_ID);
+    ap->subtype = htons(NXAST_AUTOPATH);
+    ap->id = htonl(id_int);
+    ap->ofs_nbits = nxm_encode_ofs_nbits(ofs, n_bits);
+    ap->dst = htonl(reg);
+
+    free(s);
+}
+
+int
+autopath_check(const struct nx_action_autopath *ap)
+{
+    uint32_t dst = ntohl(ap->dst);
+    int ofs = nxm_decode_ofs(ap->ofs_nbits);
+    int n_bits = nxm_decode_n_bits(ap->ofs_nbits);
+
+    if (!NXM_IS_NX_REG(dst) || NXM_NX_REG_IDX(dst) >= FLOW_N_REGS) {
+        VLOG_WARN_RL(&rl, "unsupported destination field %#"PRIx32, dst);
+    } else if (ofs + n_bits > nxm_field_bits(dst)) {
+        VLOG_WARN_RL(&rl, "destination overflows output field");
+    } else if (n_bits < 16) {
+        VLOG_WARN_RL(&rl, "minimum of 16 bits required in output field");
+    } else {
+        return 0;
+    }
+
+    return ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_ARGUMENT);
+}