X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fofp-print.c;h=41aed2fd581bf6d343decf8ef124a6bbe8e6e06f;hb=611725bb6b16a00274f5449eb9ccef7ac8b606e4;hp=8ee1af58704253df51d04f259c50c139458f4bd2;hpb=57ed58bca49da2448825e4cfd65670f1f35891f0;p=sliver-openvswitch.git

diff --git a/lib/ofp-print.c b/lib/ofp-print.c
index 8ee1af587..41aed2fd5 100644
--- a/lib/ofp-print.c
+++ b/lib/ofp-print.c
@@ -31,6 +31,7 @@
  * derivatives without specific, written prior permission.
  */
 
+#include <config.h>
 #include "ofp-print.h"
 #include "xtoxll.h"
 
@@ -43,17 +44,28 @@
 #include <ctype.h>
 
 #include "compiler.h"
-#include "util.h"
-#include "openflow.h"
+#include "dynamic-string.h"
+#include "flow.h"
+#include "ofpbuf.h"
+#include "openflow/openflow.h"
+#include "openflow/nicira-ext.h"
 #include "packets.h"
+#include "util.h"
 
-/* Dumps the contents of the Ethernet frame in the 'len' bytes starting at
- * 'data' to 'stream' using tcpdump.  'total_len' specifies the full length of
- * the Ethernet frame (of which 'len' bytes were captured).
+static void ofp_print_port_name(struct ds *string, uint16_t port);
+static void ofp_print_match(struct ds *, const struct ofp_match *,
+                            int verbosity);
+
+/* Returns a string that represents the contents of the Ethernet frame in the
+ * 'len' bytes starting at 'data' to 'stream' as output by tcpdump.
+ * 'total_len' specifies the full length of the Ethernet frame (of which 'len'
+ * bytes were captured).
+ *
+ * The caller must free the returned string.
  *
  * This starts and kills a tcpdump subprocess so it's quite expensive. */
-void ofp_print_packet(FILE *stream, const void *data, size_t len,
-                     size_t total_len)
+char *
+ofp_packet_to_string(const void *data, size_t len, size_t total_len)
 {
     struct pcap_hdr {
         uint32_t magic_number;   /* magic number */
@@ -75,17 +87,18 @@ void ofp_print_packet(FILE *stream, const void *data, size_t len,
     struct pcap_hdr ph;
     struct pcaprec_hdr prh;
 
+    struct ds ds = DS_EMPTY_INITIALIZER;
+
     char command[128];
+    FILE *pcap;
     FILE *tcpdump;
     int status;
+    int c;
 
-    fflush(stream);
-    snprintf(command, sizeof command, "tcpdump -n -r - %d>&1 2>/dev/null",
-             fileno(stream));
-    tcpdump = popen(command, "w");
-    if (!tcpdump) {
-        error(errno, "exec(\"%s\")", command);
-        return;
+    pcap = tmpfile();
+    if (!pcap) {
+        ofp_error(errno, "tmpfile");
+        return xstrdup("<error>");
     }
 
     /* The pcap reader is responsible for figuring out endianness based on the
@@ -103,131 +116,387 @@ void ofp_print_packet(FILE *stream, const void *data, size_t len,
     prh.incl_len = len;
     prh.orig_len = total_len;
 
-    fwrite(&ph, 1, sizeof ph, tcpdump);
-    fwrite(&prh, 1, sizeof prh, tcpdump);
-    fwrite(data, 1, len, tcpdump);
+    fwrite(&ph, 1, sizeof ph, pcap);
+    fwrite(&prh, 1, sizeof prh, pcap);
+    fwrite(data, 1, len, pcap);
 
-    fflush(tcpdump);
-    if (ferror(tcpdump))
-        error(errno, "error writing \"%s\" subprocess", command);
+    fflush(pcap);
+    if (ferror(pcap)) {
+        ofp_error(errno, "error writing temporary file");
+    }
+    rewind(pcap);
+
+    snprintf(command, sizeof command, "/usr/sbin/tcpdump -e -n -r /dev/fd/%d 2>/dev/null",
+             fileno(pcap));
+    tcpdump = popen(command, "r");
+    fclose(pcap);
+    if (!tcpdump) {
+        ofp_error(errno, "exec(\"%s\")", command);
+        return xstrdup("<error>");
+    }
+
+    while ((c = getc(tcpdump)) != EOF) {
+        ds_put_char(&ds, c);
+    }
 
     status = pclose(tcpdump);
     if (WIFEXITED(status)) {
         if (WEXITSTATUS(status))
-            error(0, "tcpdump exited with status %d", WEXITSTATUS(status));
+            ofp_error(0, "tcpdump exited with status %d", WEXITSTATUS(status));
     } else if (WIFSIGNALED(status)) {
-        error(0, "tcpdump exited with signal %d", WTERMSIG(status)); 
+        ofp_error(0, "tcpdump exited with signal %d", WTERMSIG(status)); 
     }
+    return ds_cstr(&ds);
 }
 
 /* Pretty-print the OFPT_PACKET_IN packet of 'len' bytes at 'oh' to 'stream'
  * at the given 'verbosity' level. */
-static void ofp_packet_in(FILE *stream, const void *oh, size_t len,
-                            int verbosity)
+static void
+ofp_packet_in(struct ds *string, const void *oh, size_t len, int verbosity)
 {
     const struct ofp_packet_in *op = oh;
     size_t data_len;
 
-    fprintf(stream, " total_len=%"PRIu16" in_port=%"PRIu8,
-            ntohs(op->total_len), ntohs(op->in_port));
+    ds_put_format(string, " total_len=%"PRIu16" in_port=",
+                  ntohs(op->total_len));
+    ofp_print_port_name(string, ntohs(op->in_port));
 
     if (op->reason == OFPR_ACTION)
-        fputs(" (via action)", stream);
+        ds_put_cstr(string, " (via action)");
     else if (op->reason != OFPR_NO_MATCH)
-        fprintf(stream, " (***reason %"PRIu8"***)", op->reason);
+        ds_put_format(string, " (***reason %"PRIu8"***)", op->reason);
 
     data_len = len - offsetof(struct ofp_packet_in, data);
-    fprintf(stream, " data_len=%zu", data_len);
+    ds_put_format(string, " data_len=%zu", data_len);
     if (htonl(op->buffer_id) == UINT32_MAX) {
-        fprintf(stream, " (unbuffered)");
+        ds_put_format(string, " (unbuffered)");
         if (ntohs(op->total_len) != data_len)
-            fprintf(stream, " (***total_len != data_len***)");
+            ds_put_format(string, " (***total_len != data_len***)");
     } else {
-        fprintf(stream, " buffer=%08"PRIx32, ntohl(op->buffer_id));
+        ds_put_format(string, " buffer=0x%08"PRIx32, ntohl(op->buffer_id));
         if (ntohs(op->total_len) < data_len)
-            fprintf(stream, " (***total_len < data_len***)");
+            ds_put_format(string, " (***total_len < data_len***)");
     }
-    putc('\n', stream);
+    ds_put_char(string, '\n');
 
-    if (verbosity > 0)
-        ofp_print_packet(stream, op->data, data_len, ntohs(op->total_len));
+    if (verbosity > 0) {
+        struct flow flow;
+        struct ofpbuf packet;
+        struct ofp_match match;
+        packet.data = (void *) op->data;
+        packet.size = data_len;
+        flow_extract(&packet, ntohs(op->in_port), &flow);
+        match.wildcards = 0;
+        match.in_port = flow.in_port;
+        memcpy(match.dl_src, flow.dl_src, ETH_ADDR_LEN);
+        memcpy(match.dl_dst, flow.dl_dst, ETH_ADDR_LEN);
+        match.dl_vlan = flow.dl_vlan;
+        match.dl_type = flow.dl_type;
+        match.nw_proto = flow.nw_proto;
+        match.pad = 0;
+        match.nw_src = flow.nw_src;
+        match.nw_dst = flow.nw_dst;
+        match.tp_src = flow.tp_src;
+        match.tp_dst = flow.tp_dst;
+        ofp_print_match(string, &match, verbosity);
+        ds_put_char(string, '\n');
+    }
+    if (verbosity > 1) {
+        char *packet = ofp_packet_to_string(op->data, data_len,
+                                            ntohs(op->total_len)); 
+        ds_put_cstr(string, packet);
+        free(packet);
+    }
 }
 
-static void ofp_print_port_name(FILE *stream, uint16_t port) 
+static void ofp_print_port_name(struct ds *string, uint16_t port) 
 {
-    if (port == UINT16_MAX) {
-        fputs("none", stream);
-    } else if (port == OFPP_FLOOD) {
-        fputs("flood", stream);
-    } else if (port == OFPP_CONTROLLER) {
-        fputs("controller", stream);
+    const char *name;
+    switch (port) {
+    case OFPP_IN_PORT:
+        name = "IN_PORT";
+        break;
+    case OFPP_TABLE:
+        name = "TABLE";
+        break;
+    case OFPP_NORMAL:
+        name = "NORMAL";
+        break;
+    case OFPP_FLOOD:
+        name = "FLOOD";
+        break;
+    case OFPP_ALL:
+        name = "ALL";
+        break;
+    case OFPP_CONTROLLER:
+        name = "CONTROLLER";
+        break;
+    case OFPP_LOCAL:
+        name = "LOCAL";
+        break;
+    case OFPP_NONE:
+        name = "NONE";
+        break;
+    default:
+        ds_put_format(string, "%"PRIu16, port);
+        return;
+    }
+    ds_put_cstr(string, name);
+}
+
+static void
+ofp_print_nx_action(struct ds *string, const struct nx_action_header *nah)
+{
+
+    if (nah->subtype == htonl(NXAST_SNAT)) {
+        const struct nx_action_snat *nas = (struct nx_action_snat *)nah;
+        uint16_t port = ntohs(nas->port);
+
+        if (port < OFPP_MAX) {
+            ds_put_format(string, "nat:%"PRIu16, port);
+        } else {
+            ds_put_format(string, "nat:%"PRIu16" (invalid port)", port);
+        }
     } else {
-        fprintf(stream, "%"PRIu16, port);
+        ds_put_format(string, "***unknown Nicira action:%d***\n", 
+                ntohl(nah->subtype));
     }
 }
 
-static void ofp_print_action(FILE *stream, const struct ofp_action *a) 
+static int
+ofp_print_action(struct ds *string, const struct ofp_action_header *ah, 
+        size_t actions_len) 
 {
-    switch (ntohs(a->type)) {
-    case OFPAT_OUTPUT:
-        fputs("output(", stream);
-        ofp_print_port_name(stream, ntohs(a->arg.output.port));
-        if (a->arg.output.port == htons(OFPP_CONTROLLER)) {
-            fprintf(stream, ", max %"PRIu16" bytes", ntohs(a->arg.output.max_len));
+    uint16_t type;
+    size_t len;
+
+    struct openflow_action {
+        size_t min_size;
+        size_t max_size;
+    };
+
+    const struct openflow_action of_actions[] = {
+        [OFPAT_OUTPUT] = {
+            sizeof(struct ofp_action_output),
+            sizeof(struct ofp_action_output),
+        },
+        [OFPAT_SET_VLAN_VID] = {
+            sizeof(struct ofp_action_vlan_vid),
+            sizeof(struct ofp_action_vlan_vid),
+        },
+        [OFPAT_SET_VLAN_PCP] = {
+            sizeof(struct ofp_action_vlan_pcp),
+            sizeof(struct ofp_action_vlan_pcp),
+        },
+        [OFPAT_STRIP_VLAN] = {
+            sizeof(struct ofp_action_header),
+            sizeof(struct ofp_action_header),
+        },
+        [OFPAT_SET_DL_SRC] = {
+            sizeof(struct ofp_action_dl_addr),
+            sizeof(struct ofp_action_dl_addr),
+        },
+        [OFPAT_SET_DL_DST] = {
+            sizeof(struct ofp_action_dl_addr),
+            sizeof(struct ofp_action_dl_addr),
+        },
+        [OFPAT_SET_NW_SRC] = {
+            sizeof(struct ofp_action_nw_addr),
+            sizeof(struct ofp_action_nw_addr),
+        },
+        [OFPAT_SET_NW_DST] = {
+            sizeof(struct ofp_action_nw_addr),
+            sizeof(struct ofp_action_nw_addr),
+        },
+        [OFPAT_SET_TP_SRC] = {
+            sizeof(struct ofp_action_tp_port),
+            sizeof(struct ofp_action_tp_port),
+        },
+        [OFPAT_SET_TP_DST] = {
+            sizeof(struct ofp_action_tp_port),
+            sizeof(struct ofp_action_tp_port),
+        }
+        /* OFPAT_VENDOR is not here, since it would blow up the array size. */
+    };
+
+    if (actions_len < sizeof *ah) {
+        ds_put_format(string, "***action array too short for next action***\n");
+        return -1;
+    }
+
+    type = ntohs(ah->type);
+    len = ntohs(ah->len);
+    if (actions_len < len) {
+        ds_put_format(string, "***truncated action %"PRIu16"***\n", type);
+        return -1;
+    }
+
+    if ((len % 8) != 0) {
+        ds_put_format(string, 
+                "***action %"PRIu16" length not a multiple of 8***\n",
+                type);
+        return -1;
+    }
+
+    if (type < ARRAY_SIZE(of_actions)) {
+        const struct openflow_action *act = &of_actions[type];
+        if ((len < act->min_size) || (len > act->max_size)) {
+            ds_put_format(string, 
+                    "***action %"PRIu16" wrong length: %zu***\n", type, len);
+            return -1;
+        }
+    }
+    
+    switch (type) {
+    case OFPAT_OUTPUT: {
+        struct ofp_action_output *oa = (struct ofp_action_output *)ah;
+        uint16_t port = ntohs(oa->port); 
+        if (port < OFPP_MAX) {
+            ds_put_format(string, "output:%"PRIu16, port);
+        } else {
+            ofp_print_port_name(string, port);
+            if (port == OFPP_CONTROLLER) {
+                if (oa->max_len) {
+                    ds_put_format(string, ":%"PRIu16, ntohs(oa->max_len));
+                } else {
+                    ds_put_cstr(string, ":all");
+                }
+            }
         }
-        fputs(")", stream);
         break;
+    }
+
+    case OFPAT_SET_VLAN_VID: {
+        struct ofp_action_vlan_vid *va = (struct ofp_action_vlan_vid *)ah;
+        ds_put_format(string, "mod_vlan_vid:%"PRIu16, ntohs(va->vlan_vid));
+        break;
+    }
+
+    case OFPAT_SET_VLAN_PCP: {
+        struct ofp_action_vlan_pcp *va = (struct ofp_action_vlan_pcp *)ah;
+        ds_put_format(string, "mod_vlan_pcp:%"PRIu8, va->vlan_pcp);
+        break;
+    }
+
+    case OFPAT_STRIP_VLAN:
+        ds_put_cstr(string, "strip_vlan");
+        break;
+
+    case OFPAT_SET_DL_SRC: {
+        struct ofp_action_dl_addr *da = (struct ofp_action_dl_addr *)ah;
+        ds_put_format(string, "mod_dl_src:"ETH_ADDR_FMT, 
+                ETH_ADDR_ARGS(da->dl_addr));
+        break;
+    }
+
+    case OFPAT_SET_DL_DST: {
+        struct ofp_action_dl_addr *da = (struct ofp_action_dl_addr *)ah;
+        ds_put_format(string, "mod_dl_dst:"ETH_ADDR_FMT, 
+                ETH_ADDR_ARGS(da->dl_addr));
+        break;
+    }
+
+    case OFPAT_SET_NW_SRC: {
+        struct ofp_action_nw_addr *na = (struct ofp_action_nw_addr *)ah;
+        ds_put_format(string, "mod_nw_src:"IP_FMT, IP_ARGS(&na->nw_addr));
+        break;
+    }
+
+    case OFPAT_SET_NW_DST: {
+        struct ofp_action_nw_addr *na = (struct ofp_action_nw_addr *)ah;
+        ds_put_format(string, "mod_nw_dst:"IP_FMT, IP_ARGS(&na->nw_addr));
+        break;
+    }
+
+    case OFPAT_SET_TP_SRC: {
+        struct ofp_action_tp_port *ta = (struct ofp_action_tp_port *)ah;
+        ds_put_format(string, "mod_tp_src:%d", ntohs(ta->tp_port));
+        break;
+    }
+
+    case OFPAT_SET_TP_DST: {
+        struct ofp_action_tp_port *ta = (struct ofp_action_tp_port *)ah;
+        ds_put_format(string, "mod_tp_dst:%d", ntohs(ta->tp_port));
+        break;
+    }
+
+    case OFPAT_VENDOR: {
+        struct ofp_action_vendor_header *avh 
+                = (struct ofp_action_vendor_header *)ah;
+        if (len < sizeof *avh) {
+            ds_put_format(string, "***ofpat_vendor truncated***\n");
+            return -1;
+        }
+        if (avh->vendor == htonl(NX_VENDOR_ID)) {
+            ofp_print_nx_action(string, (struct nx_action_header *)avh);
+        } else {
+            ds_put_format(string, "vendor action:0x%x", ntohl(avh->vendor));
+        }
+        break;
+    }
 
     default:
-        fprintf(stream, "(decoder %"PRIu16" not implemented)", ntohs(a->type));
+        ds_put_format(string, "(decoder %"PRIu16" not implemented)", type);
         break;
     }
+
+    return len;
 }
 
-static void ofp_print_actions(FILE *stream,
-                                const struct ofp_action actions[],
-                                size_t n_bytes) 
+static void 
+ofp_print_actions(struct ds *string, const struct ofp_action_header *action,
+                  size_t actions_len) 
 {
-    size_t i;
+    uint8_t *p = (uint8_t *)action;
+    size_t len = 0;
 
-    fputs(" actions[", stream);
-    for (i = 0; i < n_bytes / sizeof *actions; i++) {
-        if (i) {
-            fputs("; ", stream);
+    ds_put_cstr(string, "actions=");
+    while (actions_len > 0) {
+        if (len) {
+            ds_put_cstr(string, ",");
         }
-        ofp_print_action(stream, &actions[i]);
-    }
-    if (n_bytes % sizeof *actions) {
-        if (i) {
-            fputs("; ", stream);
+        len = ofp_print_action(string, (struct ofp_action_header *)p, 
+                actions_len);
+        if (len < 0) {
+            return;
         }
-        fputs("; ***trailing garbage***", stream);
+        p += len;
+        actions_len -= len;
     }
-    fputs("]", stream);
 }
 
-/* Pretty-print the OFPT_PACKET_OUT packet of 'len' bytes at 'oh' to 'stream'
+/* Pretty-print the OFPT_PACKET_OUT packet of 'len' bytes at 'oh' to 'string'
  * at the given 'verbosity' level. */
-static void ofp_packet_out(FILE *stream, const void *oh, size_t len,
-                            int verbosity) 
+static void ofp_packet_out(struct ds *string, const void *oh, size_t len,
+                           int verbosity) 
 {
     const struct ofp_packet_out *opo = oh;
+    size_t actions_len = ntohs(opo->actions_len);
+
+    ds_put_cstr(string, " in_port=");
+    ofp_print_port_name(string, ntohs(opo->in_port));
 
-    fputs(" in_port=", stream);
-    ofp_print_port_name(stream, ntohs(opo->in_port));
+    ds_put_format(string, " actions_len=%zu ", actions_len);
+    if (actions_len > (ntohs(opo->header.length) - sizeof *opo)) {
+        ds_put_format(string, "***packet too short for action length***\n");
+        return;
+    }
+    ofp_print_actions(string, opo->actions, actions_len);
 
     if (ntohl(opo->buffer_id) == UINT32_MAX) {
-        fputs(" out_port=", stream);
-        ofp_print_port_name(stream, ntohs(opo->out_port));
+        int data_len = len - sizeof *opo - actions_len;
+        ds_put_format(string, " data_len=%d", data_len);
         if (verbosity > 0 && len > sizeof *opo) {
-            ofp_print_packet(stream, opo->u.data, len - sizeof *opo,
-                               len - sizeof *opo);
+            char *packet = ofp_packet_to_string(
+                    (uint8_t *)opo->actions + actions_len, data_len, data_len);
+            ds_put_char(string, '\n');
+            ds_put_cstr(string, packet);
+            free(packet);
         }
     } else {
-        fprintf(stream, " buffer=%08"PRIx32, ntohl(opo->buffer_id));
-        ofp_print_actions(stream, opo->u.actions, len - sizeof *opo);
+        ds_put_format(string, " buffer=0x%08"PRIx32, ntohl(opo->buffer_id));
     }
-    putc('\n', stream);
+    ds_put_char(string, '\n');
 }
 
 /* qsort comparison function. */
@@ -242,8 +511,53 @@ compare_ports(const void *a_, const void *b_)
     return ap < bp ? -1 : ap > bp;
 }
 
-static
-void ofp_print_phy_port(FILE *stream, const struct ofp_phy_port *port)
+static void ofp_print_port_features(struct ds *string, uint32_t features)
+{
+    if (features == 0) {
+        ds_put_cstr(string, "Unsupported\n");
+        return;
+    }
+    if (features & OFPPF_10MB_HD) {
+        ds_put_cstr(string, "10MB-HD ");
+    }
+    if (features & OFPPF_10MB_FD) {
+        ds_put_cstr(string, "10MB-FD ");
+    }
+    if (features & OFPPF_100MB_HD) {
+        ds_put_cstr(string, "100MB-HD ");
+    }
+    if (features & OFPPF_100MB_FD) {
+        ds_put_cstr(string, "100MB-FD ");
+    }
+    if (features & OFPPF_1GB_HD) {
+        ds_put_cstr(string, "1GB-HD ");
+    }
+    if (features & OFPPF_1GB_FD) {
+        ds_put_cstr(string, "1GB-FD ");
+    }
+    if (features & OFPPF_10GB_FD) {
+        ds_put_cstr(string, "10GB-FD ");
+    }
+    if (features & OFPPF_COPPER) {
+        ds_put_cstr(string, "COPPER ");
+    }
+    if (features & OFPPF_FIBER) {
+        ds_put_cstr(string, "FIBER ");
+    }
+    if (features & OFPPF_AUTONEG) {
+        ds_put_cstr(string, "AUTO_NEG ");
+    }
+    if (features & OFPPF_PAUSE) {
+        ds_put_cstr(string, "AUTO_PAUSE ");
+    }
+    if (features & OFPPF_PAUSE_ASYM) {
+        ds_put_cstr(string, "AUTO_PAUSE_ASYM ");
+    }
+    ds_put_char(string, '\n');
+}
+
+static void
+ofp_print_phy_port(struct ds *string, const struct ofp_phy_port *port)
 {
     uint8_t name[OFP_MAX_PORT_NAME_LEN];
     int j;
@@ -256,229 +570,918 @@ void ofp_print_phy_port(FILE *stream, const struct ofp_phy_port *port)
     }
     name[j] = '\0';
 
-    fprintf(stream, " %2d(%s): addr:"ETH_ADDR_FMT", speed:%d, flags:%#x, "
-            "feat:%#x\n", ntohs(port->port_no), name, 
-            ETH_ADDR_ARGS(port->hw_addr), ntohl(port->speed),
-            ntohl(port->flags), ntohl(port->features));
+    ds_put_char(string, ' ');
+    ofp_print_port_name(string, ntohs(port->port_no));
+    ds_put_format(string, "(%s): addr:"ETH_ADDR_FMT", config: %#x, state:%#x\n",
+            name, ETH_ADDR_ARGS(port->hw_addr), ntohl(port->config),
+            ntohl(port->state));
+    if (port->curr) {
+        ds_put_format(string, "     current:    ");
+        ofp_print_port_features(string, ntohl(port->curr));
+    }
+    if (port->advertised) {
+        ds_put_format(string, "     advertised: ");
+        ofp_print_port_features(string, ntohl(port->advertised));
+    }
+    if (port->supported) {
+        ds_put_format(string, "     supported:  ");
+        ofp_print_port_features(string, ntohl(port->supported));
+    }
+    if (port->peer) {
+        ds_put_format(string, "     peer:       ");
+        ofp_print_port_features(string, ntohl(port->peer));
+    }
 }
 
-/* Pretty-print the OFPT_DATA_HELLO packet of 'len' bytes at 'oh' to 'stream'
- * at the given 'verbosity' level. */
-void ofp_print_data_hello(FILE *stream, const void *oh, size_t len, 
-        int verbosity)
+/* Pretty-print the struct ofp_switch_features of 'len' bytes at 'oh' to
+ * 'string' at the given 'verbosity' level. */
+static void
+ofp_print_switch_features(struct ds *string, const void *oh, size_t len,
+                          int verbosity)
 {
-    const struct ofp_data_hello *odh = oh;
-    struct ofp_phy_port port_list[OFPP_MAX];
+    const struct ofp_switch_features *osf = oh;
+    struct ofp_phy_port *port_list;
     int n_ports;
     int i;
 
+    ds_put_format(string, " ver:0x%x, dpid:%"PRIx64"\n", 
+            osf->header.version, ntohll(osf->datapath_id));
+    ds_put_format(string, "n_tables:%d, n_buffers:%d\n", osf->n_tables,
+            ntohl(osf->n_buffers));
+    ds_put_format(string, "features: capabilities:%#x, actions:%#x\n",
+           ntohl(osf->capabilities), ntohl(osf->actions));
 
-    fprintf(stream, "dp id:%"PRIx64"\n", ntohll(odh->datapath_id));
-    fprintf(stream, "tables: exact:%d, mac:%d, compressed:%d, general:%d\n",
-           ntohl(odh->n_exact), ntohl(odh->n_mac_only),
-           ntohl(odh->n_compression), ntohl(odh->n_general));
-    fprintf(stream, "buffers: size:%d, number:%d, miss_len:%d\n",
-           ntohl(odh->buffer_mb), ntohl(odh->n_buffers),
-           ntohs(odh->miss_send_len));
-    fprintf(stream, "features: capabilities:%#x, actions:%#x\n",
-           ntohl(odh->capabilities), ntohl(odh->actions));
-
-    if (ntohs(odh->header.length) >= sizeof *odh) {
-        len = MIN(len, ntohs(odh->header.length));
+    if (ntohs(osf->header.length) >= sizeof *osf) {
+        len = MIN(len, ntohs(osf->header.length));
     }
-    n_ports = (len - sizeof *odh) / sizeof *odh->ports;
+    n_ports = (len - sizeof *osf) / sizeof *osf->ports;
 
-    memcpy(port_list, odh->ports, (len - sizeof *odh));
-    qsort(port_list, n_ports, sizeof port_list[0], compare_ports);
+    port_list = xmemdup(osf->ports, len - sizeof *osf); 
+    qsort(port_list, n_ports, sizeof *port_list, compare_ports);
     for (i = 0; i < n_ports; i++) {
-        ofp_print_phy_port(stream, &port_list[i]);
+        ofp_print_phy_port(string, &port_list[i]);
+    }
+    free(port_list);
+}
+
+/* Pretty-print the struct ofp_switch_config of 'len' bytes at 'oh' to 'string'
+ * at the given 'verbosity' level. */
+static void
+ofp_print_switch_config(struct ds *string, const void *oh, size_t len,
+                        int verbosity)
+{
+    const struct ofp_switch_config *osc = oh;
+    uint16_t flags;
+
+    flags = ntohs(osc->flags);
+    if (flags & OFPC_SEND_FLOW_EXP) {
+        flags &= ~OFPC_SEND_FLOW_EXP;
+        ds_put_format(string, " (sending flow expirations)");
+    }
+    if (flags) {
+        ds_put_format(string, " ***unknown flags 0x%04"PRIx16"***", flags);
     }
+
+    ds_put_format(string, " miss_send_len=%"PRIu16"\n", ntohs(osc->miss_send_len));
 }
 
-static void print_wild(FILE *stream, const char *leader, int is_wild,
-            const char *format, ...) __attribute__((format(printf, 4, 5)));
+static void print_wild(struct ds *string, const char *leader, int is_wild,
+            int verbosity, const char *format, ...) 
+            __attribute__((format(printf, 5, 6)));
 
-static void print_wild(FILE *stream, const char *leader, int is_wild,
-                       const char *format, ...) 
+static void print_wild(struct ds *string, const char *leader, int is_wild,
+                       int verbosity, const char *format, ...) 
 {
-    fputs(leader, stream);
+    if (is_wild && verbosity < 2) {
+        return;
+    }
+    ds_put_cstr(string, leader);
     if (!is_wild) {
         va_list args;
 
         va_start(args, format);
-        vfprintf(stream, format, args);
+        ds_put_format_valist(string, format, args);
         va_end(args);
     } else {
-        putc('?', stream);
+        ds_put_char(string, '*');
+    }
+    ds_put_char(string, ',');
+}
+
+static void
+print_ip_netmask(struct ds *string, const char *leader, uint32_t ip,
+                 uint32_t wild_bits, int verbosity)
+{
+    if (wild_bits >= 32 && verbosity < 2) {
+        return;
+    }
+    ds_put_cstr(string, leader);
+    if (wild_bits < 32) {
+        ds_put_format(string, IP_FMT, IP_ARGS(&ip));
+        if (wild_bits) {
+            ds_put_format(string, "/%d", 32 - wild_bits);
+        }
+    } else {
+        ds_put_char(string, '*');
     }
+    ds_put_char(string, ',');
 }
 
 /* Pretty-print the ofp_match structure */
-static void ofp_print_match(FILE *f, const struct ofp_match *om)
+static void ofp_print_match(struct ds *f, const struct ofp_match *om, 
+        int verbosity)
 {
-    uint16_t w = ntohs(om->wildcards);
+    uint32_t w = ntohl(om->wildcards);
+    bool skip_type = false;
+    bool skip_proto = false;
 
-    print_wild(f, "inport", w & OFPFW_IN_PORT, "%04x", ntohs(om->in_port));
-    print_wild(f, ":vlan", w & OFPFW_DL_VLAN, "%04x", ntohs(om->dl_vlan));
-    print_wild(f, " mac[", w & OFPFW_DL_SRC,
+    if (!(w & OFPFW_DL_TYPE)) {
+        skip_type = true;
+        if (om->dl_type == htons(ETH_TYPE_IP)) {
+            if (!(w & OFPFW_NW_PROTO)) {
+                skip_proto = true;
+                if (om->nw_proto == IP_TYPE_ICMP) {
+                    ds_put_cstr(f, "icmp,");
+                } else if (om->nw_proto == IP_TYPE_TCP) {
+                    ds_put_cstr(f, "tcp,");
+                } else if (om->nw_proto == IP_TYPE_UDP) {
+                    ds_put_cstr(f, "udp,");
+                } else {
+                    ds_put_cstr(f, "ip,");
+                    skip_proto = false;
+                }
+            } else {
+                ds_put_cstr(f, "ip,");
+            }
+        } else if (om->dl_type == htons(ETH_TYPE_ARP)) {
+            ds_put_cstr(f, "arp,");
+        } else {
+            skip_type = false;
+        }
+    }
+    print_wild(f, "in_port=", w & OFPFW_IN_PORT, verbosity,
+               "%d", ntohs(om->in_port));
+    print_wild(f, "dl_vlan=", w & OFPFW_DL_VLAN, verbosity,
+               "0x%04x", ntohs(om->dl_vlan));
+    print_wild(f, "dl_src=", w & OFPFW_DL_SRC, verbosity,
                ETH_ADDR_FMT, ETH_ADDR_ARGS(om->dl_src));
-    print_wild(f, "->", w & OFPFW_DL_DST,
+    print_wild(f, "dl_dst=", w & OFPFW_DL_DST, verbosity,
                ETH_ADDR_FMT, ETH_ADDR_ARGS(om->dl_dst));
-    print_wild(f, "] type", w & OFPFW_DL_TYPE, "%04x", ntohs(om->dl_type));
-    print_wild(f, " ip[", w & OFPFW_NW_SRC, IP_FMT, IP_ARGS(&om->nw_src));
-    print_wild(f, "->", w & OFPFW_NW_DST, IP_FMT, IP_ARGS(&om->nw_dst));
-    print_wild(f, "] proto", w & OFPFW_NW_PROTO, "%u", om->nw_proto);
-    print_wild(f, " tport[", w & OFPFW_TP_SRC, "%d", ntohs(om->tp_src));
-    print_wild(f, "->", w & OFPFW_TP_DST, "%d", ntohs(om->tp_dst));
-    fputs("]\n", f);
+    if (!skip_type) {
+        print_wild(f, "dl_type=", w & OFPFW_DL_TYPE, verbosity,
+                   "0x%04x", ntohs(om->dl_type));
+    }
+    print_ip_netmask(f, "nw_src=", om->nw_src,
+                     (w & OFPFW_NW_SRC_MASK) >> OFPFW_NW_SRC_SHIFT, verbosity);
+    print_ip_netmask(f, "nw_dst=", om->nw_dst,
+                     (w & OFPFW_NW_DST_MASK) >> OFPFW_NW_DST_SHIFT, verbosity);
+    if (!skip_proto) {
+        print_wild(f, "nw_proto=", w & OFPFW_NW_PROTO, verbosity,
+                   "%u", om->nw_proto);
+    }
+    if (om->nw_proto == IP_TYPE_ICMP) {
+        print_wild(f, "icmp_type=", w & OFPFW_ICMP_TYPE, verbosity,
+                   "%d", ntohs(om->icmp_type));
+        print_wild(f, "icmp_code=", w & OFPFW_ICMP_CODE, verbosity,
+                   "%d", ntohs(om->icmp_code));
+    } else {
+        print_wild(f, "tp_src=", w & OFPFW_TP_SRC, verbosity,
+                   "%d", ntohs(om->tp_src));
+        print_wild(f, "tp_dst=", w & OFPFW_TP_DST, verbosity,
+                   "%d", ntohs(om->tp_dst));
+    }
 }
 
-/* Pretty-print the OFPT_FLOW_MOD packet of 'len' bytes at 'oh' to 'stream'
+/* Pretty-print the OFPT_FLOW_MOD packet of 'len' bytes at 'oh' to 'string'
  * at the given 'verbosity' level. */
-void ofp_print_flow_mod(FILE *stream, const void *oh, size_t len, 
-        int verbosity)
+static void
+ofp_print_flow_mod(struct ds *string, const void *oh, size_t len, 
+                   int verbosity)
 {
     const struct ofp_flow_mod *ofm = oh;
 
-    ofp_print_match(stream, &ofm->match);
-    fprintf(stream, " cmd:%d idle:%d buf:%#x grp:%d\n", ntohs(ofm->command),
-         ntohs(ofm->max_idle), ntohl(ofm->buffer_id), ntohl(ofm->group_id));
+    ofp_print_match(string, &ofm->match, verbosity);
+    switch (ntohs(ofm->command)) {
+    case OFPFC_ADD:
+        ds_put_cstr(string, " ADD: ");
+        break;
+    case OFPFC_MODIFY:
+        ds_put_cstr(string, " MOD: ");
+        break;
+    case OFPFC_MODIFY_STRICT:
+        ds_put_cstr(string, " MOD_STRICT: ");
+        break;
+    case OFPFC_DELETE:
+        ds_put_cstr(string, " DEL: ");
+        break;
+    case OFPFC_DELETE_STRICT:
+        ds_put_cstr(string, " DEL_STRICT: ");
+        break;
+    default:
+        ds_put_format(string, " cmd:%d ", ntohs(ofm->command));
+    }
+    ds_put_format(string, "idle:%d hard:%d pri:%d buf:%#x", 
+            ntohs(ofm->idle_timeout), ntohs(ofm->hard_timeout),
+            ofm->match.wildcards ? ntohs(ofm->priority) : (uint16_t)-1,
+            ntohl(ofm->buffer_id));
+    ofp_print_actions(string, ofm->actions,
+                      len - offsetof(struct ofp_flow_mod, actions));
+    ds_put_char(string, '\n');
 }
 
-/* Pretty-print the OFPT_FLOW_EXPIRED packet of 'len' bytes at 'oh' to 'stream'
+/* Pretty-print the OFPT_FLOW_EXPIRED packet of 'len' bytes at 'oh' to 'string'
  * at the given 'verbosity' level. */
-void ofp_print_flow_expired(FILE *stream, const void *oh, size_t len, 
-        int verbosity)
+static void
+ofp_print_flow_expired(struct ds *string, const void *oh, size_t len, 
+                       int verbosity)
 {
     const struct ofp_flow_expired *ofe = oh;
 
-    ofp_print_match(stream, &ofe->match);
-    fprintf(stream, 
-         " secs%d pkts%lld bytes%lld\n", ntohl(ofe->duration),
-         ntohll(ofe->packet_count), ntohll(ofe->byte_count));
+    ofp_print_match(string, &ofe->match, verbosity);
+    ds_put_cstr(string, " reason=");
+    switch (ofe->reason) {
+    case OFPER_IDLE_TIMEOUT:
+        ds_put_cstr(string, "idle");
+        break;
+    case OFPER_HARD_TIMEOUT:
+        ds_put_cstr(string, "hard");
+        break;
+    default:
+        ds_put_format(string, "**%"PRIu8"**", ofe->reason);
+        break;
+    }
+    ds_put_format(string, 
+         " pri%"PRIu16" secs%"PRIu32" pkts%"PRIu64" bytes%"PRIu64"\n", 
+         ofe->match.wildcards ? ntohs(ofe->priority) : (uint16_t)-1,
+         ntohl(ofe->duration), ntohll(ofe->packet_count), 
+         ntohll(ofe->byte_count));
+}
+
+static void
+ofp_print_port_mod(struct ds *string, const void *oh, size_t len,
+                   int verbosity)
+{
+    const struct ofp_port_mod *opm = oh;
+
+    ds_put_format(string, "port: %d: addr:"ETH_ADDR_FMT", config: %#x, mask:%#x\n",
+            ntohs(opm->port_no), ETH_ADDR_ARGS(opm->hw_addr), 
+            ntohl(opm->config), ntohl(opm->mask));
+    ds_put_format(string, "     advertise: ");
+    if (opm->advertise) {
+        ofp_print_port_features(string, ntohl(opm->advertise));
+    } else {
+        ds_put_format(string, "UNCHANGED\n");
+    }
 }
 
-/* Pretty-print the OFPT_PORT_STATUS packet of 'len' bytes at 'oh' to 'stream'
+struct error_type {
+    int type;
+    int code;
+    const char *name;
+};
+
+static const struct error_type error_types[] = {
+#define ERROR_TYPE(TYPE) {TYPE, -1, #TYPE}
+#define ERROR_CODE(TYPE, CODE) {TYPE, CODE, #CODE}
+    ERROR_TYPE(OFPET_HELLO_FAILED),
+    ERROR_CODE(OFPET_HELLO_FAILED, OFPHFC_INCOMPATIBLE),
+
+    ERROR_TYPE(OFPET_BAD_REQUEST),
+    ERROR_CODE(OFPET_BAD_REQUEST, OFPBRC_BAD_VERSION),
+    ERROR_CODE(OFPET_BAD_REQUEST, OFPBRC_BAD_TYPE),
+    ERROR_CODE(OFPET_BAD_REQUEST, OFPBRC_BAD_STAT),
+    ERROR_CODE(OFPET_BAD_REQUEST, OFPBRC_BAD_VERSION),
+
+    ERROR_TYPE(OFPET_BAD_ACTION),
+    ERROR_CODE(OFPET_BAD_ACTION, OFPBAC_BAD_TYPE),
+    ERROR_CODE(OFPET_BAD_ACTION, OFPBAC_BAD_LEN),
+    ERROR_CODE(OFPET_BAD_ACTION, OFPBAC_BAD_VENDOR),
+    ERROR_CODE(OFPET_BAD_ACTION, OFPBAC_BAD_VENDOR_TYPE),
+    ERROR_CODE(OFPET_BAD_ACTION, OFPBAC_BAD_OUT_PORT),
+
+    ERROR_TYPE(OFPET_FLOW_MOD_FAILED),
+    ERROR_CODE(OFPET_FLOW_MOD_FAILED, OFPFMFC_ALL_TABLES_FULL)
+};
+#define N_ERROR_TYPES ARRAY_SIZE(error_types)
+
+static const char *
+lookup_error_type(int type)
+{
+    const struct error_type *t;
+
+    for (t = error_types; t < &error_types[N_ERROR_TYPES]; t++) {
+        if (t->type == type && t->code == -1) {
+            return t->name;
+        }
+    }
+    return "?";
+}
+
+static const char *
+lookup_error_code(int type, int code)
+{
+    const struct error_type *t;
+
+    for (t = error_types; t < &error_types[N_ERROR_TYPES]; t++) {
+        if (t->type == type && t->code == code) {
+            return t->name;
+        }
+    }
+    return "?";
+}
+
+/* Pretty-print the OFPT_ERROR packet of 'len' bytes at 'oh' to 'string'
  * at the given 'verbosity' level. */
-void ofp_print_port_status(FILE *stream, const void *oh, size_t len, 
-        int verbosity)
+static void
+ofp_print_error_msg(struct ds *string, const void *oh, size_t len, 
+                       int verbosity)
+{
+    const struct ofp_error_msg *oem = oh;
+    int type = ntohs(oem->type);
+    int code = ntohs(oem->code);
+    char *s;
+
+    ds_put_format(string, " type%d(%s) code%d(%s) payload:\n",
+                  type, lookup_error_type(type),
+                  code, lookup_error_code(type, code));
+
+    switch (type) {
+    case OFPET_HELLO_FAILED:
+        ds_put_printable(string, (char *) oem->data, len - sizeof *oem);
+        break;
+
+    case OFPET_BAD_REQUEST:
+        s = ofp_to_string(oem->data, len - sizeof *oem, 1);
+        ds_put_cstr(string, s);
+        free(s);
+        break;
+
+    default:
+        ds_put_hex_dump(string, oem->data, len - sizeof *oem, 0, true);
+        break;
+    }
+}
+
+/* Pretty-print the OFPT_PORT_STATUS packet of 'len' bytes at 'oh' to 'string'
+ * at the given 'verbosity' level. */
+static void
+ofp_print_port_status(struct ds *string, const void *oh, size_t len, 
+                      int verbosity)
 {
     const struct ofp_port_status *ops = oh;
 
     if (ops->reason == OFPPR_ADD) {
-        fprintf(stream, "add:");
+        ds_put_format(string, " ADD:");
     } else if (ops->reason == OFPPR_DELETE) {
-        fprintf(stream, "del:");
-    } else if (ops->reason == OFPPR_MOD) {
-        fprintf(stream, "mod:");
+        ds_put_format(string, " DEL:");
+    } else if (ops->reason == OFPPR_MODIFY) {
+        ds_put_format(string, " MOD:");
+    }
+
+    ofp_print_phy_port(string, &ops->desc);
+}
+
+static void
+ofp_desc_stats_reply(struct ds *string, const void *body, size_t len,
+                     int verbosity)
+{
+    const struct ofp_desc_stats *ods = body;
+
+    ds_put_format(string, "Manufacturer: %s\n", ods->mfr_desc);
+    ds_put_format(string, "Hardware: %s\n", ods->hw_desc);
+    ds_put_format(string, "Software: %s\n", ods->sw_desc);
+    ds_put_format(string, "Serial Num: %s\n", ods->serial_num);
+}
+
+static void
+ofp_flow_stats_request(struct ds *string, const void *oh, size_t len,
+                      int verbosity) 
+{
+    const struct ofp_flow_stats_request *fsr = oh;
+
+    if (fsr->table_id == 0xff) {
+        ds_put_format(string, " table_id=any, ");
+    } else {
+        ds_put_format(string, " table_id=%"PRIu8", ", fsr->table_id);
+    }
+
+    ofp_print_match(string, &fsr->match, verbosity);
+}
+
+static void
+ofp_flow_stats_reply(struct ds *string, const void *body_, size_t len,
+                     int verbosity)
+{
+    const char *body = body_;
+    const char *pos = body;
+    for (;;) {
+        const struct ofp_flow_stats *fs;
+        ptrdiff_t bytes_left = body + len - pos;
+        size_t length;
+
+        if (bytes_left < sizeof *fs) {
+            if (bytes_left != 0) {
+                ds_put_format(string, " ***%td leftover bytes at end***",
+                              bytes_left);
+            }
+            break;
+        }
+
+        fs = (const void *) pos;
+        length = ntohs(fs->length);
+        if (length < sizeof *fs) {
+            ds_put_format(string, " ***length=%zu shorter than minimum %zu***",
+                          length, sizeof *fs);
+            break;
+        } else if (length > bytes_left) {
+            ds_put_format(string,
+                          " ***length=%zu but only %td bytes left***",
+                          length, bytes_left);
+            break;
+        } else if ((length - sizeof *fs) % sizeof fs->actions[0]) {
+            ds_put_format(string,
+                          " ***length=%zu has %zu bytes leftover in "
+                          "final action***",
+                          length,
+                          (length - sizeof *fs) % sizeof fs->actions[0]);
+            break;
+        }
+
+        ds_put_format(string, "  duration=%"PRIu32"s, ", ntohl(fs->duration));
+        ds_put_format(string, "table_id=%"PRIu8", ", fs->table_id);
+        ds_put_format(string, "priority=%"PRIu16", ", 
+                    fs->match.wildcards ? ntohs(fs->priority) : (uint16_t)-1);
+        ds_put_format(string, "n_packets=%"PRIu64", ",
+                    ntohll(fs->packet_count));
+        ds_put_format(string, "n_bytes=%"PRIu64", ", ntohll(fs->byte_count));
+        ds_put_format(string, "idle_timeout=%"PRIu16",",
+                      ntohs(fs->idle_timeout));
+        ds_put_format(string, "hard_timeout=%"PRIu16",",
+                      ntohs(fs->hard_timeout));
+        ofp_print_match(string, &fs->match, verbosity);
+        ofp_print_actions(string, fs->actions, length - sizeof *fs);
+        ds_put_char(string, '\n');
+
+        pos += length;
+     }
+}
+
+static void
+ofp_aggregate_stats_request(struct ds *string, const void *oh, size_t len,
+                            int verbosity) 
+{
+    const struct ofp_aggregate_stats_request *asr = oh;
+
+    if (asr->table_id == 0xff) {
+        ds_put_format(string, " table_id=any, ");
     } else {
-        fprintf(stream, "err:");
+        ds_put_format(string, " table_id=%"PRIu8", ", asr->table_id);
     }
 
-    ofp_print_phy_port(stream, &ops->desc);
+    ofp_print_match(string, &asr->match, verbosity);
+}
+
+static void
+ofp_aggregate_stats_reply(struct ds *string, const void *body_, size_t len,
+                          int verbosity)
+{
+    const struct ofp_aggregate_stats_reply *asr = body_;
+
+    ds_put_format(string, " packet_count=%"PRIu64, ntohll(asr->packet_count));
+    ds_put_format(string, " byte_count=%"PRIu64, ntohll(asr->byte_count));
+    ds_put_format(string, " flow_count=%"PRIu32, ntohl(asr->flow_count));
+}
+
+static void print_port_stat(struct ds *string, const char *leader, 
+                            uint64_t stat, int more)
+{
+    ds_put_cstr(string, leader);
+    if (stat != -1) {
+        ds_put_format(string, "%"PRIu64, stat);
+    } else {
+        ds_put_char(string, '?');
+    }
+    if (more) {
+        ds_put_cstr(string, ", ");
+    } else {
+        ds_put_cstr(string, "\n");
+    }
+}
+
+static void
+ofp_port_stats_reply(struct ds *string, const void *body, size_t len,
+                     int verbosity)
+{
+    const struct ofp_port_stats *ps = body;
+    size_t n = len / sizeof *ps;
+    ds_put_format(string, " %zu ports\n", n);
+    if (verbosity < 1) {
+        return;
+    }
+
+    for (; n--; ps++) {
+        ds_put_format(string, "  port %2"PRIu16": ", ntohs(ps->port_no));
+
+        ds_put_cstr(string, "rx ");
+        print_port_stat(string, "pkts=", ntohll(ps->rx_packets), 1);
+        print_port_stat(string, "bytes=", ntohll(ps->rx_bytes), 1);
+        print_port_stat(string, "drop=", ntohll(ps->rx_dropped), 1);
+        print_port_stat(string, "errs=", ntohll(ps->rx_errors), 1);
+        print_port_stat(string, "frame=", ntohll(ps->rx_frame_err), 1);
+        print_port_stat(string, "over=", ntohll(ps->rx_over_err), 1);
+        print_port_stat(string, "crc=", ntohll(ps->rx_crc_err), 0);
+
+        ds_put_cstr(string, "           tx ");
+        print_port_stat(string, "pkts=", ntohll(ps->tx_packets), 1);
+        print_port_stat(string, "bytes=", ntohll(ps->tx_bytes), 1);
+        print_port_stat(string, "drop=", ntohll(ps->tx_dropped), 1);
+        print_port_stat(string, "errs=", ntohll(ps->tx_errors), 1);
+        print_port_stat(string, "coll=", ntohll(ps->collisions), 0);
+    }
+}
+
+static void
+ofp_table_stats_reply(struct ds *string, const void *body, size_t len,
+                     int verbosity)
+{
+    const struct ofp_table_stats *ts = body;
+    size_t n = len / sizeof *ts;
+    ds_put_format(string, " %zu tables\n", n);
+    if (verbosity < 1) {
+        return;
+    }
+
+    for (; n--; ts++) {
+        char name[OFP_MAX_TABLE_NAME_LEN + 1];
+        strncpy(name, ts->name, sizeof name);
+        name[OFP_MAX_TABLE_NAME_LEN] = '\0';
+
+        ds_put_format(string, "  %d: %-8s: ", ts->table_id, name);
+        ds_put_format(string, "wild=0x%05"PRIx32", ", ntohl(ts->wildcards));
+        ds_put_format(string, "max=%6"PRIu32", ", ntohl(ts->max_entries));
+        ds_put_format(string, "active=%"PRIu32"\n", ntohl(ts->active_count));
+        ds_put_cstr(string, "               ");
+        ds_put_format(string, "lookup=%"PRIu64", ", 
+                    ntohll(ts->lookup_count));
+        ds_put_format(string, "matched=%"PRIu64"\n",
+                    ntohll(ts->matched_count));
+     }
+}
+
+static void
+vendor_stat(struct ds *string, const void *body, size_t len,
+            int verbosity UNUSED)
+{
+    ds_put_format(string, " vendor=%08"PRIx32, ntohl(*(uint32_t *) body));
+    ds_put_format(string, " %zu bytes additional data",
+                  len - sizeof(uint32_t));
+}
+
+enum stats_direction {
+    REQUEST,
+    REPLY
+};
+
+static void
+print_stats(struct ds *string, int type, const void *body, size_t body_len,
+            int verbosity, enum stats_direction direction)
+{
+    struct stats_msg {
+        size_t min_body, max_body;
+        void (*printer)(struct ds *, const void *, size_t len, int verbosity);
+    };
+
+    struct stats_type {
+        int type;
+        const char *name;
+        struct stats_msg request;
+        struct stats_msg reply;
+    };
+
+    static const struct stats_type stats_types[] = {
+        {
+            OFPST_DESC,
+            "description",
+            { 0, 0, NULL },
+            { 0, SIZE_MAX, ofp_desc_stats_reply },
+        },
+        {
+            OFPST_FLOW,
+            "flow",
+            { sizeof(struct ofp_flow_stats_request),
+              sizeof(struct ofp_flow_stats_request),
+              ofp_flow_stats_request },
+            { 0, SIZE_MAX, ofp_flow_stats_reply },
+        },
+        {
+            OFPST_AGGREGATE,
+            "aggregate",
+            { sizeof(struct ofp_aggregate_stats_request),
+              sizeof(struct ofp_aggregate_stats_request),
+              ofp_aggregate_stats_request },
+            { sizeof(struct ofp_aggregate_stats_reply),
+              sizeof(struct ofp_aggregate_stats_reply),
+              ofp_aggregate_stats_reply },
+        },
+        {
+            OFPST_TABLE,
+            "table",
+            { 0, 0, NULL },
+            { 0, SIZE_MAX, ofp_table_stats_reply },
+        },
+        {
+            OFPST_PORT,
+            "port",
+            { 0, 0, NULL, },
+            { 0, SIZE_MAX, ofp_port_stats_reply },
+        },
+        {
+            OFPST_VENDOR,
+            "vendor-specific",
+            { sizeof(uint32_t), SIZE_MAX, vendor_stat },
+            { sizeof(uint32_t), SIZE_MAX, vendor_stat },
+        },
+        {
+            -1,
+            "unknown",
+            { 0, 0, NULL, },
+            { 0, 0, NULL, },
+        },
+    };
+
+    const struct stats_type *s;
+    const struct stats_msg *m;
+
+    if (type >= ARRAY_SIZE(stats_types) || !stats_types[type].name) {
+        ds_put_format(string, " ***unknown type %d***", type);
+        return;
+    }
+    for (s = stats_types; s->type >= 0; s++) {
+        if (s->type == type) {
+            break;
+        }
+    }
+    ds_put_format(string, " type=%d(%s)\n", type, s->name);
+
+    m = direction == REQUEST ? &s->request : &s->reply;
+    if (body_len < m->min_body || body_len > m->max_body) {
+        ds_put_format(string, " ***body_len=%zu not in %zu...%zu***",
+                      body_len, m->min_body, m->max_body);
+        return;
+    }
+    if (m->printer) {
+        m->printer(string, body, body_len, verbosity);
+    }
+}
+
+static void
+ofp_stats_request(struct ds *string, const void *oh, size_t len, int verbosity)
+{
+    const struct ofp_stats_request *srq = oh;
+
+    if (srq->flags) {
+        ds_put_format(string, " ***unknown flags 0x%04"PRIx16"***",
+                      ntohs(srq->flags));
+    }
+
+    print_stats(string, ntohs(srq->type), srq->body,
+                len - offsetof(struct ofp_stats_request, body),
+                verbosity, REQUEST);
+}
+
+static void
+ofp_stats_reply(struct ds *string, const void *oh, size_t len, int verbosity)
+{
+    const struct ofp_stats_reply *srp = oh;
+
+    ds_put_cstr(string, " flags=");
+    if (!srp->flags) {
+        ds_put_cstr(string, "none");
+    } else {
+        uint16_t flags = ntohs(srp->flags);
+        if (flags & OFPSF_REPLY_MORE) {
+            ds_put_cstr(string, "[more]");
+            flags &= ~OFPSF_REPLY_MORE;
+        }
+        if (flags) {
+            ds_put_format(string, "[***unknown flags 0x%04"PRIx16"***]", flags);
+        }
+    }
+
+    print_stats(string, ntohs(srp->type), srp->body,
+                len - offsetof(struct ofp_stats_reply, body),
+                verbosity, REPLY);
+}
+
+static void
+ofp_echo(struct ds *string, const void *oh, size_t len, int verbosity)
+{
+    const struct ofp_header *hdr = oh;
+
+    ds_put_format(string, " %zu bytes of payload\n", len - sizeof *hdr);
+    if (verbosity > 1) {
+        ds_put_hex_dump(string, hdr, len - sizeof *hdr, 0, true); 
+    }
 }
 
 struct openflow_packet {
+    uint8_t type;
     const char *name;
     size_t min_size;
-    void (*printer)(FILE *, const void *, size_t len, int verbosity);
+    void (*printer)(struct ds *, const void *, size_t len, int verbosity);
 };
 
 static const struct openflow_packet packets[] = {
-    [OFPT_CONTROL_HELLO] = {
-        "ofp_control_hello",
-        sizeof (struct ofp_control_hello),
+    {
+        OFPT_HELLO,
+        "hello",
+        sizeof (struct ofp_header),
+        NULL,
+    },
+    {
+        OFPT_FEATURES_REQUEST,
+        "features_request",
+        sizeof (struct ofp_header),
+        NULL,
+    },
+    {
+        OFPT_FEATURES_REPLY,
+        "features_reply",
+        sizeof (struct ofp_switch_features),
+        ofp_print_switch_features,
+    },
+    {
+        OFPT_GET_CONFIG_REQUEST,
+        "get_config_request",
+        sizeof (struct ofp_header),
         NULL,
     },
-    [OFPT_DATA_HELLO] = {
-        "ofp_data_hello",
-        sizeof (struct ofp_data_hello),
-        ofp_print_data_hello,
+    {
+        OFPT_GET_CONFIG_REPLY,
+        "get_config_reply",
+        sizeof (struct ofp_switch_config),
+        ofp_print_switch_config,
+    },
+    {
+        OFPT_SET_CONFIG,
+        "set_config",
+        sizeof (struct ofp_switch_config),
+        ofp_print_switch_config,
     },
-    [OFPT_PACKET_IN] = {
-        "ofp_packet_in",
+    {
+        OFPT_PACKET_IN,
+        "packet_in",
         offsetof(struct ofp_packet_in, data),
         ofp_packet_in,
     },
-    [OFPT_PACKET_OUT] = {
-        "ofp_packet_out",
+    {
+        OFPT_PACKET_OUT,
+        "packet_out",
         sizeof (struct ofp_packet_out),
         ofp_packet_out,
     },
-    [OFPT_FLOW_MOD] = {
-        "ofp_flow_mod",
+    {
+        OFPT_FLOW_MOD,
+        "flow_mod",
         sizeof (struct ofp_flow_mod),
         ofp_print_flow_mod,
     },
-    [OFPT_FLOW_EXPIRED] = {
-        "ofp_flow_expired",
+    {
+        OFPT_FLOW_EXPIRED,
+        "flow_expired",
         sizeof (struct ofp_flow_expired),
         ofp_print_flow_expired,
     },
-    [OFPT_PORT_MOD] = {
-        "ofp_port_mod",
+    {
+        OFPT_PORT_MOD,
+        "port_mod",
         sizeof (struct ofp_port_mod),
-        NULL,
+        ofp_print_port_mod,
     },
-    [OFPT_PORT_STATUS] = {
-        "ofp_port_status",
+    {
+        OFPT_PORT_STATUS,
+        "port_status",
         sizeof (struct ofp_port_status),
         ofp_print_port_status
     },
+    {
+        OFPT_ERROR,
+        "error_msg",
+        sizeof (struct ofp_error_msg),
+        ofp_print_error_msg,
+    },
+    {
+        OFPT_STATS_REQUEST,
+        "stats_request",
+        sizeof (struct ofp_stats_request),
+        ofp_stats_request,
+    },
+    {
+        OFPT_STATS_REPLY,
+        "stats_reply",
+        sizeof (struct ofp_stats_reply),
+        ofp_stats_reply,
+    },
+    {
+        OFPT_ECHO_REQUEST,
+        "echo_request",
+        sizeof (struct ofp_header),
+        ofp_echo,
+    },
+    {
+        OFPT_ECHO_REPLY,
+        "echo_reply",
+        sizeof (struct ofp_header),
+        ofp_echo,
+    },
 };
 
-/* Pretty-print the OpenFlow packet of 'len' bytes at 'oh' to 'stream' at the
- * given 'verbosity' level.  0 is a minimal amount of verbosity and higher
- * numbers increase verbosity. */
-void ofp_print(FILE *stream, const void *oh_, size_t len, int verbosity)
+/* Composes and returns a string representing the OpenFlow packet of 'len'
+ * bytes at 'oh' at the given 'verbosity' level.  0 is a minimal amount of
+ * verbosity and higher numbers increase verbosity.  The caller is responsible
+ * for freeing the string. */
+char *
+ofp_to_string(const void *oh_, size_t len, int verbosity)
 {
+    struct ds string = DS_EMPTY_INITIALIZER;
     const struct ofp_header *oh = oh_;
     const struct openflow_packet *pkt;
 
     if (len < sizeof(struct ofp_header)) {
-        fprintf(stream, "OpenFlow packet too short:\n");
-        hex_dump(stream, oh, len, 0, true);
-        return;
-    } else if (oh->version != 1) {
-        fprintf(stream, "Bad OpenFlow version %"PRIu8":\n", oh->version);
-        hex_dump(stream, oh, len, 0, true);
-        return;
-    } else if (oh->type >= ARRAY_SIZE(packets) || !packets[oh->type].name) {
-        fprintf(stream, "Unknown OpenFlow packet type %"PRIu8":\n",
-                oh->type);
-        hex_dump(stream, oh, len, 0, true);
-        return;
+        ds_put_cstr(&string, "OpenFlow packet too short:\n");
+        ds_put_hex_dump(&string, oh, len, 0, true);
+        return ds_cstr(&string);
+    } else if (oh->version != OFP_VERSION) {
+        ds_put_format(&string, "Bad OpenFlow version %"PRIu8":\n", oh->version);
+        ds_put_hex_dump(&string, oh, len, 0, true);
+        return ds_cstr(&string);
     }
 
-    pkt = &packets[oh->type];
-    fprintf(stream, "%s (xid=%"PRIx32"):", pkt->name, oh->xid);
+    for (pkt = packets; ; pkt++) {
+        if (pkt >= &packets[ARRAY_SIZE(packets)]) {
+            ds_put_format(&string, "Unknown OpenFlow packet type %"PRIu8":\n",
+                          oh->type);
+            ds_put_hex_dump(&string, oh, len, 0, true);
+            return ds_cstr(&string);
+        } else if (oh->type == pkt->type) {
+            break;
+        }
+    }
+
+    ds_put_format(&string, "%s (xid=0x%"PRIx32"):", pkt->name, oh->xid);
 
     if (ntohs(oh->length) > len)
-        fprintf(stream, " (***truncated to %zu bytes from %"PRIu16"***)",
+        ds_put_format(&string, " (***truncated to %zu bytes from %"PRIu16"***)",
                 len, ntohs(oh->length));
     else if (ntohs(oh->length) < len) {
-        fprintf(stream, " (***only uses %"PRIu16" bytes out of %zu***)\n",
+        ds_put_format(&string, " (***only uses %"PRIu16" bytes out of %zu***)\n",
                 ntohs(oh->length), len);
         len = ntohs(oh->length);
     }
 
     if (len < pkt->min_size) {
-        fprintf(stream, " (***length=%zu < min_size=%zu***)\n",
+        ds_put_format(&string, " (***length=%zu < min_size=%zu***)\n",
                 len, pkt->min_size);
     } else if (!pkt->printer) {
-        fprintf(stream, " length=%zu (decoder not implemented)\n",
-                ntohs(oh->length));
+        if (len > sizeof *oh) {
+            ds_put_format(&string, " length=%"PRIu16" (decoder not implemented)\n",
+                          ntohs(oh->length)); 
+        }
     } else {
-        pkt->printer(stream, oh, len, verbosity);
+        pkt->printer(&string, oh, len, verbosity);
     }
-    if (verbosity >= 3)
-        hex_dump(stream, oh, len, 0, true);
+    if (verbosity >= 3) {
+        ds_put_hex_dump(&string, oh, len, 0, true);
+    }
+    if (string.string[string.length - 1] != '\n') {
+        ds_put_char(&string, '\n');
+    }
+    return ds_cstr(&string);
+}
+
+static void
+print_and_free(FILE *stream, char *string) 
+{
+    fputs(string, stream);
+    free(string);
+}
+
+/* Pretty-print the OpenFlow packet of 'len' bytes at 'oh' to 'stream' at the
+ * given 'verbosity' level.  0 is a minimal amount of verbosity and higher
+ * numbers increase verbosity. */
+void
+ofp_print(FILE *stream, const void *oh, size_t len, int verbosity)
+{
+    print_and_free(stream, ofp_to_string(oh, len, verbosity));
 }
 
-/* Pretty print a openflow table */
-void ofp_print_table(FILE *stream, const struct ofp_table* ot)
+/* Dumps the contents of the Ethernet frame in the 'len' bytes starting at
+ * 'data' to 'stream' using tcpdump.  'total_len' specifies the full length of
+ * the Ethernet frame (of which 'len' bytes were captured).
+ *
+ * This starts and kills a tcpdump subprocess so it's quite expensive. */
+void
+ofp_print_packet(FILE *stream, const void *data, size_t len, size_t total_len)
 {
-    fprintf(stream, "id: %d name: %-8s n_flows: %6d max_flows: %6d",
-            ntohs(ot->table_id), ot->name, ntohl(ot->n_flows),
-            ntohl(ot->max_flows));
+    print_and_free(stream, ofp_packet_to_string(data, len, total_len));
 }