/* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
 * Junior University
 * 
 * We are making the OpenFlow specification and associated documentation
 * (Software) available for public use and benefit with the expectation
 * that others will use, modify and enhance the Software and contribute
 * those enhancements back to the community. However, since we would
 * like to make the Software available for broadest use, with as few
 * restrictions as possible permission is hereby granted, free of
 * charge, to any person obtaining a copy of this Software to deal in
 * the Software under the copyrights without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * 
 * The name and trademarks of copyright holder(s) may NOT be used in
 * advertising or publicity pertaining to the Software or any
 * derivatives without specific, written prior permission.
 */

#include <config.h>
#include <arpa/inet.h>
#include <errno.h>
#include <getopt.h>
#include <inttypes.h>
#include <netinet/in.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>

#ifdef HAVE_NETLINK
#include "netdev.h"
#include "netlink.h"
#include "openflow/openflow-netlink.h"
#endif

#include "command-line.h"
#include "compiler.h"
#include "dpif.h"
#include "openflow/nicira-ext.h"
#include "ofp-print.h"
#include "ofpbuf.h"
#include "openflow/openflow.h"
#include "packets.h"
#include "random.h"
#include "socket-util.h"
#include "timeval.h"
#include "util.h"
#include "vconn-ssl.h"
#include "vconn.h"

#include "vlog.h"
#define THIS_MODULE VLM_dpctl

#define DEFAULT_IDLE_TIMEOUT 60

/* Maximum size of action buffer for adding and modify flows */
#define MAX_ACT_LEN 60

#define MOD_PORT_CMD_UP      "up"
#define MOD_PORT_CMD_DOWN    "down"
#define MOD_PORT_CMD_FLOOD   "flood"
#define MOD_PORT_CMD_NOFLOOD "noflood"


/* Settings that may be configured by the user. */
struct settings {
    bool strict;        /* Use strict matching for flow mod commands */
};

struct command {
    const char *name;
    int min_args;
    int max_args;
    void (*handler)(const struct settings *, int argc, char *argv[]);
};

static struct command all_commands[];

static void usage(void) NO_RETURN;
static void parse_options(int argc, char *argv[], struct settings *);

int main(int argc, char *argv[])
{
    struct settings s;
    struct command *p;

    set_program_name(argv[0]);
    time_init();
    vlog_init();
    parse_options(argc, argv, &s);
    signal(SIGPIPE, SIG_IGN);

    argc -= optind;
    argv += optind;
    if (argc < 1)
        ofp_fatal(0, "missing command name; use --help for help");

    for (p = all_commands; p->name != NULL; p++) {
        if (!strcmp(p->name, argv[0])) {
            int n_arg = argc - 1;
            if (n_arg < p->min_args)
                ofp_fatal(0, "'%s' command requires at least %d arguments",
                          p->name, p->min_args);
            else if (n_arg > p->max_args)
                ofp_fatal(0, "'%s' command takes at most %d arguments",
                          p->name, p->max_args);
            else {
                p->handler(&s, argc, argv);
                exit(0);
            }
        }
    }
    ofp_fatal(0, "unknown command '%s'; use --help for help", argv[0]);

    return 0;
}

static void
parse_options(int argc, char *argv[], struct settings *s)
{
    enum {
        OPT_STRICT = UCHAR_MAX + 1
    };
    static struct option long_options[] = {
        {"timeout", required_argument, 0, 't'},
        {"verbose", optional_argument, 0, 'v'},
        {"strict", no_argument, 0, OPT_STRICT},
        {"help", no_argument, 0, 'h'},
        {"version", no_argument, 0, 'V'},
        VCONN_SSL_LONG_OPTIONS
        {0, 0, 0, 0},
    };
    char *short_options = long_options_to_short_options(long_options);

    /* Set defaults that we can figure out before parsing options. */
    s->strict = false;

    for (;;) {
        unsigned long int timeout;
        int c;

        c = getopt_long(argc, argv, short_options, long_options, NULL);
        if (c == -1) {
            break;
        }

        switch (c) {
        case 't':
            timeout = strtoul(optarg, NULL, 10);
            if (timeout <= 0) {
                ofp_fatal(0, "value %s on -t or --timeout is not at least 1",
                          optarg);
            } else {
                time_alarm(timeout);
            }
            break;

        case 'h':
            usage();

        case 'V':
            printf("%s %s compiled "__DATE__" "__TIME__"\n",
                   program_name, VERSION BUILDNR);
            exit(EXIT_SUCCESS);

        case 'v':
            vlog_set_verbosity(optarg);
            break;

        case OPT_STRICT:
            s->strict = true;
            break;

        VCONN_SSL_OPTION_HANDLERS

        case '?':
            exit(EXIT_FAILURE);

        default:
            abort();
        }
    }
    free(short_options);
}

static void
usage(void)
{
    printf("%s: OpenFlow switch management utility\n"
           "usage: %s [OPTIONS] COMMAND [ARG...]\n"
#ifdef HAVE_NETLINK
           "\nFor local datapaths only:\n"
           "  adddp nl:DP_ID              add a new local datapath DP_ID\n"
           "  deldp nl:DP_ID              delete local datapath DP_ID\n"
           "  addif nl:DP_ID IFACE...     add each IFACE as a port on DP_ID\n"
           "  delif nl:DP_ID IFACE...     delete each IFACE from DP_ID\n"
#endif
           "\nFor local datapaths and remote switches:\n"
           "  show SWITCH                 show basic information\n"
           "  status SWITCH [KEY]         report statistics (about KEY)\n"
           "  dump-desc SWITCH            print switch description\n"
           "  dump-tables SWITCH          print table stats\n"
           "  mod-port SWITCH IFACE ACT   modify port behavior\n"
           "  dump-ports SWITCH           print port statistics\n"
           "  dump-flows SWITCH           print all flow entries\n"
           "  dump-flows SWITCH FLOW      print matching FLOWs\n"
           "  dump-aggregate SWITCH       print aggregate flow statistics\n"
           "  dump-aggregate SWITCH FLOW  print aggregate stats for FLOWs\n"
#ifdef SUPPORT_SNAT
           "  add-snat SWITCH IFACE IP    add SNAT config to IFACE\n"
           "  del-snat SWITCH IFACE       delete SNAT config on IFACE\n"
#endif
           "  add-flow SWITCH FLOW        add flow described by FLOW\n"
           "  add-flows SWITCH FILE       add flows from FILE\n"
           "  mod-flows SWITCH FLOW       modify actions of matching FLOWs\n"
           "  del-flows SWITCH [FLOW]     delete matching FLOWs\n"
           "  monitor SWITCH              print packets received from SWITCH\n"
           "  execute SWITCH CMD [ARG...] execute CMD with ARGS on SWITCH\n"
           "\nFor local datapaths, remote switches, and controllers:\n"
           "  probe VCONN                 probe whether VCONN is up\n"
           "  ping VCONN [N]              latency of N-byte echos\n"
           "  benchmark VCONN N COUNT     bandwidth of COUNT N-byte echos\n"
           "where each SWITCH is an active OpenFlow connection method.\n",
           program_name, program_name);
    vconn_usage(true, false, false);
    vlog_usage();
    printf("\nOther options:\n"
           "  --strict                    use strict match for flow commands\n"
           "  -t, --timeout=SECS          give up after SECS seconds\n"
           "  -h, --help                  display this help message\n"
           "  -V, --version               display version information\n");
    exit(EXIT_SUCCESS);
}

static void run(int retval, const char *message, ...)
    PRINTF_FORMAT(2, 3);

static void run(int retval, const char *message, ...)
{
    if (retval) {
        va_list args;

        fprintf(stderr, "%s: ", program_name);
        va_start(args, message);
        vfprintf(stderr, message, args);
        va_end(args);
        if (retval == EOF) {
            fputs(": unexpected end of file\n", stderr);
        } else {
            fprintf(stderr, ": %s\n", strerror(retval));
        }

        exit(EXIT_FAILURE);
    }
}

#ifdef HAVE_NETLINK
/* Netlink-only commands. */

static int if_up(const char *netdev_name)
{
    struct netdev *netdev;
    int retval;

    retval = netdev_open(netdev_name, NETDEV_ETH_TYPE_NONE, &netdev);
    if (!retval) {
        retval = netdev_turn_flags_on(netdev, NETDEV_UP, true);
        netdev_close(netdev);
    }
    return retval;
}

static void open_nl_vconn(const char *name, bool subscribe, struct dpif *dpif)
{
    if (strncmp(name, "nl:", 3)
        || strlen(name) < 4
        || name[strspn(name + 3, "0123456789") + 3]) {
        ofp_fatal(0, "%s: argument is not of the form \"nl:DP_ID\"", name);
    }
    run(dpif_open(atoi(name + 3), subscribe, dpif), "opening datapath");
}

static void do_add_dp(const struct settings *s, int argc UNUSED, char *argv[])
{
    struct dpif dp;
    open_nl_vconn(argv[1], false, &dp);
    run(dpif_add_dp(&dp), "add_dp");
    dpif_close(&dp);
}

static void do_del_dp(const struct settings *s, int argc UNUSED, char *argv[])
{
    struct dpif dp;
    open_nl_vconn(argv[1], false, &dp);
    run(dpif_del_dp(&dp), "del_dp");
    dpif_close(&dp);
}

static void add_del_ports(int argc UNUSED, char *argv[],
                          int (*function)(struct dpif *, const char *netdev),
                          const char *operation, const char *preposition)
{
    struct dpif dp;
    bool failure = false;
    int i;

    open_nl_vconn(argv[1], false, &dp);
    for (i = 2; i < argc; i++) {
        int retval = function(&dp, argv[i]);
        if (retval) {
            ofp_error(retval, "failed to %s %s %s %s",
                      operation, argv[i], preposition, argv[1]);
            failure = true;
        }
    }
    dpif_close(&dp);
    if (failure) {
        exit(EXIT_FAILURE);
    }
}

static int ifup_and_add_port(struct dpif *dpif, const char *netdev)
{
    int retval = if_up(netdev);
    return retval ? retval : dpif_add_port(dpif, netdev);
}

static void do_add_port(const struct settings *s, int argc UNUSED, 
        char *argv[])
{
    add_del_ports(argc, argv, ifup_and_add_port, "add", "to");
}

static void do_del_port(const struct settings *s, int argc UNUSED, 
        char *argv[])
{
    add_del_ports(argc, argv, dpif_del_port, "remove", "from");
}
#endif /* HAVE_NETLINK */

/* Generic commands. */

static void
open_vconn(const char *name, struct vconn **vconnp)
{
    run(vconn_open_block(name, OFP_VERSION, vconnp), "connecting to %s", name);
}

static void *
alloc_stats_request(size_t body_len, uint16_t type, struct ofpbuf **bufferp)
{
    struct ofp_stats_request *rq;
    rq = make_openflow((offsetof(struct ofp_stats_request, body)
                        + body_len), OFPT_STATS_REQUEST, bufferp);
    rq->type = htons(type);
    rq->flags = htons(0);
    return rq->body;
}

static void
send_openflow_buffer(struct vconn *vconn, struct ofpbuf *buffer)
{
    update_openflow_length(buffer);
    run(vconn_send_block(vconn, buffer), "failed to send packet to switch");
}

static void
dump_transaction(const char *vconn_name, struct ofpbuf *request)
{
    struct vconn *vconn;
    struct ofpbuf *reply;

    update_openflow_length(request);
    open_vconn(vconn_name, &vconn);
    run(vconn_transact(vconn, request, &reply), "talking to %s", vconn_name);
    ofp_print(stdout, reply->data, reply->size, 1);
    vconn_close(vconn);
}

static void
dump_trivial_transaction(const char *vconn_name, uint8_t request_type)
{
    struct ofpbuf *request;
    make_openflow(sizeof(struct ofp_header), request_type, &request);
    dump_transaction(vconn_name, request);
}

static void
dump_stats_transaction(const char *vconn_name, struct ofpbuf *request)
{
    uint32_t send_xid = ((struct ofp_header *) request->data)->xid;
    struct vconn *vconn;
    bool done = false;

    open_vconn(vconn_name, &vconn);
    send_openflow_buffer(vconn, request);
    while (!done) {
        uint32_t recv_xid;
        struct ofpbuf *reply;

        run(vconn_recv_block(vconn, &reply), "OpenFlow packet receive failed");
        recv_xid = ((struct ofp_header *) reply->data)->xid;
        if (send_xid == recv_xid) {
            struct ofp_stats_reply *osr;

            ofp_print(stdout, reply->data, reply->size, 1);

            osr = ofpbuf_at(reply, 0, sizeof *osr);
            done = !osr || !(ntohs(osr->flags) & OFPSF_REPLY_MORE);
        } else {
            VLOG_DBG("received reply with xid %08"PRIx32" "
                     "!= expected %08"PRIx32, recv_xid, send_xid);
        }
        ofpbuf_delete(reply);
    }
    vconn_close(vconn);
}

static void
dump_trivial_stats_transaction(const char *vconn_name, uint8_t stats_type)
{
    struct ofpbuf *request;
    alloc_stats_request(0, stats_type, &request);
    dump_stats_transaction(vconn_name, request);
}

static void
do_show(const struct settings *s, int argc UNUSED, char *argv[])
{
    dump_trivial_transaction(argv[1], OFPT_FEATURES_REQUEST);
    dump_trivial_transaction(argv[1], OFPT_GET_CONFIG_REQUEST);
}

static void
do_status(const struct settings *s, int argc, char *argv[])
{
    struct nicira_header *request, *reply;
    struct vconn *vconn;
    struct ofpbuf *b;

    request = make_openflow(sizeof *request, OFPT_VENDOR, &b);
    request->vendor = htonl(NX_VENDOR_ID);
    request->subtype = htonl(NXT_STATUS_REQUEST);
    if (argc > 2) {
        ofpbuf_put(b, argv[2], strlen(argv[2]));
    }
    open_vconn(argv[1], &vconn);
    run(vconn_transact(vconn, b, &b), "talking to %s", argv[1]);
    vconn_close(vconn);

    if (b->size < sizeof *reply) {
        ofp_fatal(0, "short reply (%zu bytes)", b->size);
    }
    reply = b->data;
    if (reply->header.type != OFPT_VENDOR
        || reply->vendor != ntohl(NX_VENDOR_ID)
        || reply->subtype != ntohl(NXT_STATUS_REPLY)) {
        ofp_print(stderr, b->data, b->size, 2);
        ofp_fatal(0, "bad reply");
    }

    fwrite(reply + 1, b->size, 1, stdout);
}

static void
do_dump_desc(const struct settings *s, int argc, char *argv[])
{
    dump_trivial_stats_transaction(argv[1], OFPST_DESC);
}

static void
do_dump_tables(const struct settings *s, int argc, char *argv[])
{
    dump_trivial_stats_transaction(argv[1], OFPST_TABLE);
}


static uint32_t
str_to_int(const char *str) 
{
    char *tail;
    uint32_t value;

    errno = 0;
    value = strtoul(str, &tail, 0);
    if (errno == EINVAL || errno == ERANGE || *tail) {
        ofp_fatal(0, "invalid numeric format %s", str);
    }
    return value;
}

static void
str_to_mac(const char *str, uint8_t mac[6]) 
{
    if (sscanf(str, "%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8":%"SCNx8,
               &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]) != 6) {
        ofp_fatal(0, "invalid mac address %s", str);
    }
}

static uint32_t
str_to_ip(const char *str_, uint32_t *ip)
{
    char *str = xstrdup(str_);
    char *save_ptr = NULL;
    const char *name, *netmask;
    struct in_addr in_addr;
    int n_wild, retval;

    name = strtok_r(str, "//", &save_ptr);
    retval = name ? lookup_ip(name, &in_addr) : EINVAL;
    if (retval) {
        ofp_fatal(0, "%s: could not convert to IP address", str);
    }
    *ip = in_addr.s_addr;

    netmask = strtok_r(NULL, "//", &save_ptr);
    if (netmask) {
        uint8_t o[4];
        if (sscanf(netmask, "%"SCNu8".%"SCNu8".%"SCNu8".%"SCNu8,
                   &o[0], &o[1], &o[2], &o[3]) == 4) {
            uint32_t nm = (o[0] << 24) | (o[1] << 16) | (o[2] << 8) | o[3];
            int i;

            /* Find first 1-bit. */
            for (i = 0; i < 32; i++) {
                if (nm & (1u << i)) {
                    break;
                }
            }
            n_wild = i;

            /* Verify that the rest of the bits are 1-bits. */
            for (; i < 32; i++) {
                if (!(nm & (1u << i))) {
                    ofp_fatal(0, "%s: %s is not a valid netmask",
                              str, netmask);
                }
            }
        } else {
            int prefix = atoi(netmask);
            if (prefix <= 0 || prefix > 32) {
                ofp_fatal(0, "%s: network prefix bits not between 1 and 32",
                          str);
            }
            n_wild = 32 - prefix;
        }
    } else {
        n_wild = 0;
    }

    free(str);
    return n_wild;
}

static void
str_to_action(char *str, struct ofp_action_header *actions, 
        size_t *actions_len) 
{
    size_t len = *actions_len;
    char *act, *arg;
    char *saveptr = NULL;
    uint8_t *p = (uint8_t *)actions;
    
    memset(actions, 0, len);
    for (act = strtok_r(str, ", \t\r\n", &saveptr); 
         (len >= sizeof(struct ofp_action_header)) && act;
         act = strtok_r(NULL, ", \t\r\n", &saveptr)) 
    {
        uint16_t port;
        struct ofp_action_header *ah = (struct ofp_action_header *)p;
        int act_len = sizeof *ah;
        port = OFPP_MAX;

        /* Arguments are separated by colons */
        arg = strchr(act, ':');
        if (arg) {
            *arg = '\0';
            arg++;
        } 

        if (!strcasecmp(act, "mod_vlan_vid")) {
            struct ofp_action_vlan_vid *va = (struct ofp_action_vlan_vid *)ah;

            if (len < sizeof *va) {
                ofp_fatal(0, "Insufficient room for vlan vid action\n");
            }

            act_len = sizeof *va;
            va->type = htons(OFPAT_SET_VLAN_VID);
            va->vlan_vid = htons(str_to_int(arg));
        } else if (!strcasecmp(act, "mod_vlan_pcp")) {
            struct ofp_action_vlan_pcp *va = (struct ofp_action_vlan_pcp *)ah;

            if (len < sizeof *va) {
                ofp_fatal(0, "Insufficient room for vlan pcp action\n");
            }

            act_len = sizeof *va;
            va->type = htons(OFPAT_SET_VLAN_PCP);
            va->vlan_pcp = str_to_int(arg);
        } else if (!strcasecmp(act, "strip_vlan")) {
            ah->type = htons(OFPAT_STRIP_VLAN);
        } else if (!strcasecmp(act, "output")) {
            port = str_to_int(arg);
#ifdef SUPPORT_SNAT
        } else if (!strcasecmp(act, "nat")) {
            struct nx_action_snat *sa = (struct nx_action_snat *)ah;

            if (len < sizeof *sa) {
                ofp_fatal(0, "Insufficient room for SNAT action\n");
            }

            if (str_to_int(arg) > OFPP_MAX) {
                ofp_fatal(0, "Invalid nat port: %s\n", arg);
            }

            act_len = sizeof *sa;
            sa->type = htons(OFPAT_VENDOR);
            sa->vendor = htonl(NX_VENDOR_ID);
            sa->subtype = htons(NXAST_SNAT);
            sa->port = htons(str_to_int(arg));
#endif
        } else if (!strcasecmp(act, "TABLE")) {
            port = OFPP_TABLE;
        } else if (!strcasecmp(act, "NORMAL")) {
            port = OFPP_NORMAL;
        } else if (!strcasecmp(act, "FLOOD")) {
            port = OFPP_FLOOD;
        } else if (!strcasecmp(act, "ALL")) {
            port = OFPP_ALL;
        } else if (!strcasecmp(act, "CONTROLLER")) {
            struct ofp_action_output *ca = (struct ofp_action_output *)ah;

            if (act_len < sizeof *ca) {
                ofp_fatal(0, "Insufficient room for controller action\n");
            }

            act_len = sizeof *ca;
            ca->type = htons(OFPAT_OUTPUT);
            ca->port = htons(OFPP_CONTROLLER);

            /* Unless a numeric argument is specified, we send the whole
             * packet to the controller. */
            if (arg && (strspn(act, "0123456789") == strlen(act))) {
               ca->max_len= htons(str_to_int(arg));
            }
        } else if (!strcasecmp(act, "LOCAL")) {
            port = OFPP_LOCAL;
        } else if (strspn(act, "0123456789") == strlen(act)) {
            port = str_to_int(act);
        } else {
            ofp_fatal(0, "Unknown action: %s", act);
        }

        if (port != OFPP_MAX) {
            struct ofp_action_output *oa = (struct ofp_action_output *)p;

            if (act_len < sizeof *oa) {
                ofp_fatal(0, "Insufficient room for output action\n");
            }

            act_len = sizeof *oa;
            oa->type = htons(OFPAT_OUTPUT);
            oa->port = htons(port);
        }

        ah->len = htons(act_len);
        p += act_len;
        len -= act_len;
    }

    *actions_len -= len;
}

struct protocol {
    const char *name;
    uint16_t dl_type;
    uint8_t nw_proto;
};

static bool
parse_protocol(const char *name, const struct protocol **p_out)
{
    static const struct protocol protocols[] = {
        { "ip", ETH_TYPE_IP },
        { "arp", ETH_TYPE_ARP },
        { "icmp", ETH_TYPE_IP, IP_TYPE_ICMP },
        { "tcp", ETH_TYPE_IP, IP_TYPE_TCP },
        { "udp", ETH_TYPE_IP, IP_TYPE_UDP },
    };
    const struct protocol *p;

    for (p = protocols; p < &protocols[ARRAY_SIZE(protocols)]; p++) {
        if (!strcmp(p->name, name)) {
            *p_out = p;
            return true;
        }
    }
    *p_out = NULL;
    return false;
}

struct field {
    const char *name;
    uint32_t wildcard;
    enum { F_U8, F_U16, F_MAC, F_IP } type;
    size_t offset, shift;
};

static bool
parse_field(const char *name, const struct field **f_out) 
{
#define F_OFS(MEMBER) offsetof(struct ofp_match, MEMBER)
    static const struct field fields[] = { 
        { "in_port", OFPFW_IN_PORT, F_U16, F_OFS(in_port) },
        { "dl_vlan", OFPFW_DL_VLAN, F_U16, F_OFS(dl_vlan) },
        { "dl_src", OFPFW_DL_SRC, F_MAC, F_OFS(dl_src) },
        { "dl_dst", OFPFW_DL_DST, F_MAC, F_OFS(dl_dst) },
        { "dl_type", OFPFW_DL_TYPE, F_U16, F_OFS(dl_type) },
        { "nw_src", OFPFW_NW_SRC_MASK, F_IP,
          F_OFS(nw_src), OFPFW_NW_SRC_SHIFT },
        { "nw_dst", OFPFW_NW_DST_MASK, F_IP,
          F_OFS(nw_dst), OFPFW_NW_DST_SHIFT },
        { "nw_proto", OFPFW_NW_PROTO, F_U8, F_OFS(nw_proto) },
        { "tp_src", OFPFW_TP_SRC, F_U16, F_OFS(tp_src) },
        { "tp_dst", OFPFW_TP_DST, F_U16, F_OFS(tp_dst) },
        { "icmp_type", OFPFW_ICMP_TYPE, F_U16, F_OFS(icmp_type) },
        { "icmp_code", OFPFW_ICMP_CODE, F_U16, F_OFS(icmp_code) }
    };
    const struct field *f;

    for (f = fields; f < &fields[ARRAY_SIZE(fields)]; f++) {
        if (!strcmp(f->name, name)) {
            *f_out = f;
            return true;
        }
    }
    *f_out = NULL;
    return false;
}

static void
str_to_flow(char *string, struct ofp_match *match, 
            struct ofp_action_header *actions, size_t *actions_len, 
            uint8_t *table_idx, uint16_t *out_port, uint16_t *priority, 
            uint16_t *idle_timeout, uint16_t *hard_timeout)
{

    char *name;
    uint32_t wildcards;

    if (table_idx) {
        *table_idx = 0xff;
    }
    if (out_port) {
        *out_port = OFPP_NONE;
    }
    if (priority) {
        *priority = OFP_DEFAULT_PRIORITY;
    }
    if (idle_timeout) {
        *idle_timeout = DEFAULT_IDLE_TIMEOUT;
    }
    if (hard_timeout) {
        *hard_timeout = OFP_FLOW_PERMANENT;
    }
    if (actions) {
        char *act_str = strstr(string, "action");
        if (!act_str) {
            ofp_fatal(0, "must specify an action");
        }
        *(act_str-1) = '\0';

        act_str = strchr(act_str, '=');
        if (!act_str) {
            ofp_fatal(0, "must specify an action");
        }

        act_str++;

        str_to_action(act_str, actions, actions_len);
    }
    memset(match, 0, sizeof *match);
    wildcards = OFPFW_ALL;
    for (name = strtok(string, "=, \t\r\n"); name;
         name = strtok(NULL, "=, \t\r\n")) {
        const struct protocol *p;

        if (parse_protocol(name, &p)) {
            wildcards &= ~OFPFW_DL_TYPE;
            match->dl_type = htons(p->dl_type);
            if (p->nw_proto) {
                wildcards &= ~OFPFW_NW_PROTO;
                match->nw_proto = p->nw_proto;
            }
        } else {
            const struct field *f;
            char *value;

            value = strtok(NULL, ", \t\r\n");
            if (!value) {
                ofp_fatal(0, "field %s missing value", name);
            }
        
            if (table_idx && !strcmp(name, "table")) {
                *table_idx = atoi(value);
            } else if (out_port && !strcmp(name, "out_port")) {
                *out_port = atoi(value);
            } else if (priority && !strcmp(name, "priority")) {
                *priority = atoi(value);
            } else if (idle_timeout && !strcmp(name, "idle_timeout")) {
                *idle_timeout = atoi(value);
            } else if (hard_timeout && !strcmp(name, "hard_timeout")) {
                *hard_timeout = atoi(value);
            } else if (parse_field(name, &f)) {
                void *data = (char *) match + f->offset;
                if (!strcmp(value, "*") || !strcmp(value, "ANY")) {
                    wildcards |= f->wildcard;
                } else {
                    wildcards &= ~f->wildcard;
                    if (f->type == F_U8) {
                        *(uint8_t *) data = str_to_int(value);
                    } else if (f->type == F_U16) {
                        *(uint16_t *) data = htons(str_to_int(value));
                    } else if (f->type == F_MAC) {
                        str_to_mac(value, data);
                    } else if (f->type == F_IP) {
                        wildcards |= str_to_ip(value, data) << f->shift;
                    } else {
                        NOT_REACHED();
                    }
                }
            } else {
                ofp_fatal(0, "unknown keyword %s", name);
            }
        }
    }
    match->wildcards = htonl(wildcards);
}

static void do_dump_flows(const struct settings *s, int argc, char *argv[])
{
    struct ofp_flow_stats_request *req;
    uint16_t out_port;
    struct ofpbuf *request;

    req = alloc_stats_request(sizeof *req, OFPST_FLOW, &request);
    str_to_flow(argc > 2 ? argv[2] : "", &req->match, NULL, 0, 
                &req->table_id, &out_port, NULL, NULL, NULL);
    memset(&req->pad, 0, sizeof req->pad);
    req->out_port = htons(out_port);

    dump_stats_transaction(argv[1], request);
}

static void do_dump_aggregate(const struct settings *s, int argc, 
        char *argv[])
{
    struct ofp_aggregate_stats_request *req;
    struct ofpbuf *request;
    uint16_t out_port;

    req = alloc_stats_request(sizeof *req, OFPST_AGGREGATE, &request);
    str_to_flow(argc > 2 ? argv[2] : "", &req->match, NULL, 0,
                &req->table_id, &out_port, NULL, NULL, NULL);
    memset(&req->pad, 0, sizeof req->pad);
    req->out_port = htons(out_port);

    dump_stats_transaction(argv[1], request);
}

#ifdef SUPPORT_SNAT
static void do_add_snat(const struct settings *s, int argc, char *argv[])
{
    struct vconn *vconn;
    struct ofpbuf *buffer;
    struct nx_act_config *nac;
    size_t size;

    /* Parse and send. */
    size = sizeof *nac + sizeof nac->snat[0];
    nac = make_openflow(size, OFPT_VENDOR, &buffer);

    nac->header.vendor = htonl(NX_VENDOR_ID);
    nac->header.subtype = htonl(NXT_ACT_SET_CONFIG);

    nac->type = htons(NXAST_SNAT);
    nac->snat[0].command = NXSC_ADD;
    nac->snat[0].port = htons(str_to_int(argv[2]));
    nac->snat[0].mac_timeout = htons(0);
    str_to_ip(argv[3], &nac->snat[0].ip_addr_start);
    str_to_ip(argv[3], &nac->snat[0].ip_addr_end);

    open_vconn(argv[1], &vconn);
    send_openflow_buffer(vconn, buffer);
    vconn_close(vconn);
}

static void do_del_snat(const struct settings *s, int argc, char *argv[])
{
    struct vconn *vconn;
    struct ofpbuf *buffer;
    struct nx_act_config *nac;
    size_t size;

    /* Parse and send. */
    size = sizeof *nac + sizeof nac->snat[0];
    nac = make_openflow(size, OFPT_VENDOR, &buffer);

    nac->header.vendor = htonl(NX_VENDOR_ID);
    nac->header.subtype = htonl(NXT_ACT_SET_CONFIG);

    nac->type = htons(NXAST_SNAT);
    nac->snat[0].command = NXSC_DELETE;
    nac->snat[0].port = htons(str_to_int(argv[2]));
    nac->snat[0].mac_timeout = htons(0);

    open_vconn(argv[1], &vconn);
    send_openflow_buffer(vconn, buffer);
    vconn_close(vconn);
}
#endif /* SUPPORT_SNAT */

static void do_add_flow(const struct settings *s, int argc, char *argv[])
{
    struct vconn *vconn;
    struct ofpbuf *buffer;
    struct ofp_flow_mod *ofm;
    uint16_t priority, idle_timeout, hard_timeout;
    size_t size;
    size_t actions_len = MAX_ACT_LEN;

    /* Parse and send. */
    size = sizeof *ofm + actions_len;
    ofm = make_openflow(size, OFPT_FLOW_MOD, &buffer);
    str_to_flow(argv[2], &ofm->match, &ofm->actions[0], &actions_len, 
                NULL, NULL, &priority, &idle_timeout, &hard_timeout);
    ofm->command = htons(OFPFC_ADD);
    ofm->idle_timeout = htons(idle_timeout);
    ofm->hard_timeout = htons(hard_timeout);
    ofm->buffer_id = htonl(UINT32_MAX);
    ofm->priority = htons(priority);
    ofm->reserved = htonl(0);

    /* xxx Should we use the ofpbuf library? */
    buffer->size -= MAX_ACT_LEN - actions_len;

    open_vconn(argv[1], &vconn);
    send_openflow_buffer(vconn, buffer);
    vconn_close(vconn);
}

static void do_add_flows(const struct settings *s, int argc, char *argv[])
{
    struct vconn *vconn;
    FILE *file;
    char line[1024];

    file = fopen(argv[2], "r");
    if (file == NULL) {
        ofp_fatal(errno, "%s: open", argv[2]);
    }

    open_vconn(argv[1], &vconn);
    while (fgets(line, sizeof line, file)) {
        struct ofpbuf *buffer;
        struct ofp_flow_mod *ofm;
        uint16_t priority, idle_timeout, hard_timeout;
        size_t size;
        size_t actions_len = MAX_ACT_LEN;

        char *comment;

        /* Delete comments. */
        comment = strchr(line, '#');
        if (comment) {
            *comment = '\0';
        }

        /* Drop empty lines. */
        if (line[strspn(line, " \t\n")] == '\0') {
            continue;
        }

        /* Parse and send. */
        size = sizeof *ofm + actions_len;
        ofm = make_openflow(size, OFPT_FLOW_MOD, &buffer);
        str_to_flow(line, &ofm->match, &ofm->actions[0], &actions_len, 
                    NULL, NULL, &priority, &idle_timeout, &hard_timeout);
        ofm->command = htons(OFPFC_ADD);
        ofm->idle_timeout = htons(idle_timeout);
        ofm->hard_timeout = htons(hard_timeout);
        ofm->buffer_id = htonl(UINT32_MAX);
        ofm->priority = htons(priority);
        ofm->reserved = htonl(0);

        /* xxx Should we use the ofpbuf library? */
        buffer->size -= MAX_ACT_LEN - actions_len;

        send_openflow_buffer(vconn, buffer);
    }
    vconn_close(vconn);
    fclose(file);
}

static void do_mod_flows(const struct settings *s, int argc, char *argv[])
{
    uint16_t priority, idle_timeout, hard_timeout;
    struct vconn *vconn;
    struct ofpbuf *buffer;
    struct ofp_flow_mod *ofm;
    size_t size;
    size_t actions_len = MAX_ACT_LEN;

    /* Parse and send. */
    size = sizeof *ofm + actions_len;
    ofm = make_openflow(size, OFPT_FLOW_MOD, &buffer);
    str_to_flow(argv[2], &ofm->match, &ofm->actions[0], &actions_len, 
                NULL, NULL, &priority, &idle_timeout, &hard_timeout);
    if (s->strict) {
        ofm->command = htons(OFPFC_MODIFY_STRICT);
    } else {
        ofm->command = htons(OFPFC_MODIFY);
    }
    ofm->idle_timeout = htons(idle_timeout);
    ofm->hard_timeout = htons(hard_timeout);
    ofm->buffer_id = htonl(UINT32_MAX);
    ofm->priority = htons(priority);
    ofm->reserved = htonl(0);

    /* xxx Should we use the buffer library? */
    buffer->size -= MAX_ACT_LEN - actions_len;

    open_vconn(argv[1], &vconn);
    send_openflow_buffer(vconn, buffer);
    vconn_close(vconn);
}

static void do_del_flows(const struct settings *s, int argc, char *argv[])
{
    struct vconn *vconn;
    uint16_t priority;
    uint16_t out_port;
    struct ofpbuf *buffer;
    struct ofp_flow_mod *ofm;
    size_t size;

    /* Parse and send. */
    size = sizeof *ofm;
    ofm = make_openflow(size, OFPT_FLOW_MOD, &buffer);
    str_to_flow(argc > 2 ? argv[2] : "", &ofm->match, NULL, 0, NULL, 
                &out_port, &priority, NULL, NULL);
    if (s->strict) {
        ofm->command = htons(OFPFC_DELETE_STRICT);
    } else {
        ofm->command = htons(OFPFC_DELETE);
    }
    ofm->idle_timeout = htons(0);
    ofm->hard_timeout = htons(0);
    ofm->buffer_id = htonl(UINT32_MAX);
    ofm->out_port = htons(out_port);
    ofm->priority = htons(priority);
    ofm->reserved = htonl(0);

    open_vconn(argv[1], &vconn);
    send_openflow_buffer(vconn, buffer);
    vconn_close(vconn);
}

static void
do_monitor(const struct settings *s, int argc UNUSED, char *argv[])
{
    struct vconn *vconn;
    const char *name;

    /* If the user specified, e.g., "nl:0", append ":1" to it to ensure that
     * the connection will subscribe to listen for asynchronous messages, such
     * as packet-in messages. */
    if (!strncmp(argv[1], "nl:", 3) && strrchr(argv[1], ':') == &argv[1][2]) {
        name = xasprintf("%s:1", argv[1]);
    } else {
        name = argv[1];
    }
    open_vconn(argv[1], &vconn);
    for (;;) {
        struct ofpbuf *b;
        run(vconn_recv_block(vconn, &b), "vconn_recv");
        ofp_print(stderr, b->data, b->size, 2);
        ofpbuf_delete(b);
    }
}

static void
do_dump_ports(const struct settings *s, int argc, char *argv[])
{
    dump_trivial_stats_transaction(argv[1], OFPST_PORT);
}

static void
do_probe(const struct settings *s, int argc, char *argv[])
{
    struct ofpbuf *request;
    struct vconn *vconn;
    struct ofpbuf *reply;

    make_openflow(sizeof(struct ofp_header), OFPT_ECHO_REQUEST, &request);
    open_vconn(argv[1], &vconn);
    run(vconn_transact(vconn, request, &reply), "talking to %s", argv[1]);
    if (reply->size != request->size) {
        ofp_fatal(0, "reply does not match request");
    }
    ofpbuf_delete(reply);
    vconn_close(vconn);
}

static void
do_mod_port(const struct settings *s, int argc, char *argv[])
{
    struct ofpbuf *request, *reply;
    struct ofp_switch_features *osf;
    struct ofp_port_mod *opm;
    struct vconn *vconn;
    char *endptr;
    int n_ports;
    int port_idx;
    int port_no;
    

    /* Check if the argument is a port index.  Otherwise, treat it as
     * the port name. */
    port_no = strtol(argv[2], &endptr, 10);
    if (port_no == 0 && endptr == argv[2]) {
        port_no = -1;
    }

    /* Send a "Features Request" to get the information we need in order 
     * to modify the port. */
    make_openflow(sizeof(struct ofp_header), OFPT_FEATURES_REQUEST, &request);
    open_vconn(argv[1], &vconn);
    run(vconn_transact(vconn, request, &reply), "talking to %s", argv[1]);

    osf = reply->data;
    n_ports = (reply->size - sizeof *osf) / sizeof *osf->ports;

    for (port_idx = 0; port_idx < n_ports; port_idx++) {
        if (port_no != -1) {
            /* Check argument as a port index */
            if (osf->ports[port_idx].port_no == htons(port_no)) {
                break;
            }
        } else {
            /* Check argument as an interface name */
            if (!strncmp((char *)osf->ports[port_idx].name, argv[2], 
                        sizeof osf->ports[0].name)) {
                break;
            }

        }
    }
    if (port_idx == n_ports) {
        ofp_fatal(0, "couldn't find monitored port: %s", argv[2]);
    }

    opm = make_openflow(sizeof(struct ofp_port_mod), OFPT_PORT_MOD, &request);
    opm->port_no = osf->ports[port_idx].port_no;
    memcpy(opm->hw_addr, osf->ports[port_idx].hw_addr, sizeof opm->hw_addr);
    opm->config = htonl(0);
    opm->mask = htonl(0);
    opm->advertise = htonl(0);

    printf("modifying port: %s\n", osf->ports[port_idx].name);

    if (!strncasecmp(argv[3], MOD_PORT_CMD_UP, sizeof MOD_PORT_CMD_UP)) {
        opm->mask |= htonl(OFPPC_PORT_DOWN);
    } else if (!strncasecmp(argv[3], MOD_PORT_CMD_DOWN, 
                sizeof MOD_PORT_CMD_DOWN)) {
        opm->mask |= htonl(OFPPC_PORT_DOWN);
        opm->config |= htonl(OFPPC_PORT_DOWN);
    } else if (!strncasecmp(argv[3], MOD_PORT_CMD_FLOOD, 
                sizeof MOD_PORT_CMD_FLOOD)) {
        opm->mask |= htonl(OFPPC_NO_FLOOD);
    } else if (!strncasecmp(argv[3], MOD_PORT_CMD_NOFLOOD, 
                sizeof MOD_PORT_CMD_NOFLOOD)) {
        opm->mask |= htonl(OFPPC_NO_FLOOD);
        opm->config |= htonl(OFPPC_NO_FLOOD);
    } else {
        ofp_fatal(0, "unknown mod-port command '%s'", argv[3]);
    }

    send_openflow_buffer(vconn, request);

    ofpbuf_delete(reply);
    vconn_close(vconn);
}

static void
do_ping(const struct settings *s, int argc, char *argv[])
{
    size_t max_payload = 65535 - sizeof(struct ofp_header);
    unsigned int payload;
    struct vconn *vconn;
    int i;

    payload = argc > 2 ? atoi(argv[2]) : 64;
    if (payload > max_payload) {
        ofp_fatal(0, "payload must be between 0 and %zu bytes", max_payload);
    }

    open_vconn(argv[1], &vconn);
    for (i = 0; i < 10; i++) {
        struct timeval start, end;
        struct ofpbuf *request, *reply;
        struct ofp_header *rq_hdr, *rpy_hdr;

        rq_hdr = make_openflow(sizeof(struct ofp_header) + payload,
                               OFPT_ECHO_REQUEST, &request);
        random_bytes(rq_hdr + 1, payload);

        gettimeofday(&start, NULL);
        run(vconn_transact(vconn, ofpbuf_clone(request), &reply), "transact");
        gettimeofday(&end, NULL);

        rpy_hdr = reply->data;
        if (reply->size != request->size
            || memcmp(rpy_hdr + 1, rq_hdr + 1, payload)
            || rpy_hdr->xid != rq_hdr->xid
            || rpy_hdr->type != OFPT_ECHO_REPLY) {
            printf("Reply does not match request.  Request:\n");
            ofp_print(stdout, request, request->size, 2);
            printf("Reply:\n");
            ofp_print(stdout, reply, reply->size, 2);
        }
        printf("%d bytes from %s: xid=%08"PRIx32" time=%.1f ms\n",
               reply->size - sizeof *rpy_hdr, argv[1], rpy_hdr->xid,
                   (1000*(double)(end.tv_sec - start.tv_sec))
                   + (.001*(end.tv_usec - start.tv_usec)));
        ofpbuf_delete(request);
        ofpbuf_delete(reply);
    }
    vconn_close(vconn);
}

static void
do_benchmark(const struct settings *s, int argc, char *argv[])
{
    size_t max_payload = 65535 - sizeof(struct ofp_header);
    struct timeval start, end;
    unsigned int payload_size, message_size;
    struct vconn *vconn;
    double duration;
    int count;
    int i;

    payload_size = atoi(argv[2]);
    if (payload_size > max_payload) {
        ofp_fatal(0, "payload must be between 0 and %zu bytes", max_payload);
    }
    message_size = sizeof(struct ofp_header) + payload_size;

    count = atoi(argv[3]);

    printf("Sending %d packets * %u bytes (with header) = %u bytes total\n",
           count, message_size, count * message_size);

    open_vconn(argv[1], &vconn);
    gettimeofday(&start, NULL);
    for (i = 0; i < count; i++) {
        struct ofpbuf *request, *reply;
        struct ofp_header *rq_hdr;

        rq_hdr = make_openflow(message_size, OFPT_ECHO_REQUEST, &request);
        memset(rq_hdr + 1, 0, payload_size);
        run(vconn_transact(vconn, request, &reply), "transact");
        ofpbuf_delete(reply);
    }
    gettimeofday(&end, NULL);
    vconn_close(vconn);

    duration = ((1000*(double)(end.tv_sec - start.tv_sec))
                + (.001*(end.tv_usec - start.tv_usec)));
    printf("Finished in %.1f ms (%.0f packets/s) (%.0f bytes/s)\n",
           duration, count / (duration / 1000.0),
           count * message_size / (duration / 1000.0));
}

static void
do_execute(const struct settings *s, int argc, char *argv[])
{
    struct vconn *vconn;
    struct ofpbuf *request;
    struct nicira_header *nicira;
    struct nx_command_reply *ncr;
    uint32_t xid;
    int i;

    nicira = make_openflow(sizeof *nicira, OFPT_VENDOR, &request);
    xid = nicira->header.xid;
    nicira->vendor = htonl(NX_VENDOR_ID);
    nicira->subtype = htonl(NXT_COMMAND_REQUEST);
    ofpbuf_put(request, argv[2], strlen(argv[2]));
    for (i = 3; i < argc; i++) {
        ofpbuf_put_zeros(request, 1);
        ofpbuf_put(request, argv[i], strlen(argv[i]));
    }
    update_openflow_length(request);

    open_vconn(argv[1], &vconn);
    run(vconn_send_block(vconn, request), "send");

    for (;;) {
        struct ofpbuf *reply;
        uint32_t status;

        run(vconn_recv_xid(vconn, xid, &reply), "recv_xid");
        if (reply->size < sizeof *ncr) {
            ofp_fatal(0, "reply is too short (%zu bytes < %zu bytes)",
                      reply->size, sizeof *ncr);
        }
        ncr = reply->data;
        if (ncr->nxh.header.type != OFPT_VENDOR
            || ncr->nxh.vendor != htonl(NX_VENDOR_ID)
            || ncr->nxh.subtype != htonl(NXT_COMMAND_REPLY)) {
            ofp_fatal(0, "reply is invalid");
        }

        status = ntohl(ncr->status);
        if (status & NXT_STATUS_STARTED) {
            /* Wait for a second reply. */
            continue;
        } else if (status & NXT_STATUS_EXITED) {
            fprintf(stderr, "process terminated normally with exit code %d",
                    status & NXT_STATUS_EXITSTATUS);
        } else if (status & NXT_STATUS_SIGNALED) {
            fprintf(stderr, "process terminated by signal %d",
                    status & NXT_STATUS_TERMSIG);
        } else if (status & NXT_STATUS_ERROR) {
            fprintf(stderr, "error executing command");
        } else {
            fprintf(stderr, "process terminated for unknown reason");
        }
        if (status & NXT_STATUS_COREDUMP) {
            fprintf(stderr, " (core dumped)");
        }
        putc('\n', stderr);

        fwrite(ncr + 1, reply->size - sizeof *ncr, 1, stdout);
        break;
    }
}

static void do_help(const struct settings *s, int argc UNUSED, 
        char *argv[] UNUSED)
{
    usage();
}

static struct command all_commands[] = {
#ifdef HAVE_NETLINK
    { "adddp", 1, 1, do_add_dp },
    { "deldp", 1, 1, do_del_dp },
    { "addif", 2, INT_MAX, do_add_port },
    { "delif", 2, INT_MAX, do_del_port },
#endif

    { "show", 1, 1, do_show },
    { "status", 1, 2, do_status },

    { "help", 0, INT_MAX, do_help },
    { "monitor", 1, 1, do_monitor },
    { "dump-desc", 1, 1, do_dump_desc },
    { "dump-tables", 1, 1, do_dump_tables },
    { "dump-flows", 1, 2, do_dump_flows },
    { "dump-aggregate", 1, 2, do_dump_aggregate },
#ifdef SUPPORT_SNAT
    { "add-snat", 3, 3, do_add_snat },
    { "del-snat", 2, 2, do_del_snat },
#endif
    { "add-flow", 2, 2, do_add_flow },
    { "add-flows", 2, 2, do_add_flows },
    { "mod-flows", 2, 2, do_mod_flows },
    { "del-flows", 1, 2, do_del_flows },
    { "dump-ports", 1, 1, do_dump_ports },
    { "mod-port", 3, 3, do_mod_port },
    { "probe", 1, 1, do_probe },
    { "ping", 1, 2, do_ping },
    { "benchmark", 3, 3, do_benchmark },
    { "execute", 2, INT_MAX, do_execute },
    { NULL, 0, 0, NULL },
};