/*
 * write.c
 *
 * Copyright (c) 2002 Archie L. Cobbs
 * All rights reserved.
 *
 * Subject to the following obligations and disclaimer of warranty, use and
 * redistribution of this software, in source or object code forms, with or
 * without modifications are expressly permitted by Archie L. Cobbs;
 * provided, however, that:
 * 1. Any and all reproductions of the source or object code must include the
 *    copyright notice above and the following disclaimer of warranties
 *
 * THIS SOFTWARE IS BEING PROVIDED BY ARCHIE L. COBBS AS IS", AND TO
 * THE MAXIMUM EXTENT PERMITTED BY LAW, ARCHIE L. COBBS MAKES NO
 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
 * ARCHIE L. COBBS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
 * IN NO EVENT SHALL ARCHIE L. COBBS BE LIABLE FOR ANY DAMAGES
 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ARCHIE L. COBBS IS ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/socket.h>

#include <err.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <netgraph/ng_message.h>
#include <netgraph/ng_socket.h>

#include "ngctl.h"

#define BUF_SIZE        8192

static int WriteCmd(int ac, char **av);

const struct ngcmd write_cmd = {
        WriteCmd,
        "write hook < -f file | byte ... >",
        "Send a data packet down the hook named by \"hook\".",
        "The data may be contained in a file, or may be described directly"
        " on the command line by supplying a sequence of bytes.",
        { "w" }
};

static int
WriteCmd(int ac, char **av)
{
        u_int32_t sagbuf[64];
        struct sockaddr_ng *sag = (struct sockaddr_ng *)sagbuf;
        u_char buf[BUF_SIZE];
        const char *hook;
        size_t hooklen;
        FILE *fp;
        u_int len;
        int byte;
        int i;

        /* Get arguments */
        if (ac < 3)
                return (CMDRTN_USAGE);
        hook = av[1];
        _Static_assert(sizeof(sagbuf) >=
            offsetof(struct sockaddr_ng, sg_data) + NG_HOOKSIZ,
            "sagbuf is too small for NG_HOOKSIZ");
        hooklen = strlcpy(sag->sg_data, hook, NG_HOOKSIZ);
        if (hooklen >= NG_HOOKSIZ) {
                warnx("hook name \"%s\" too long", hook);
                return (CMDRTN_ERROR);
        }

        /* Get data */
        if (strcmp(av[2], "-f") == 0) {
                if (ac != 4)
                        return (CMDRTN_USAGE);
                if ((fp = fopen(av[3], "r")) == NULL) {
                        warn("can't read file \"%s\"", av[3]);
                        return (CMDRTN_ERROR);
                }
                if ((len = fread(buf, 1, sizeof(buf), fp)) == 0) {
                        if (ferror(fp))
                                warn("can't read file \"%s\"", av[3]);
                        else
                                warnx("file \"%s\" is empty", av[3]);
                        fclose(fp);
                        return (CMDRTN_ERROR);
                }
                fclose(fp);
        } else {
                for (i = 2, len = 0; i < ac && len < sizeof(buf); i++, len++) {
                        if (sscanf(av[i], "%i", &byte) != 1 ||
                            byte < -128 || byte > 255) {
                                warnx("invalid byte \"%s\"", av[i]);
                                return (CMDRTN_ERROR);
                        }
                        buf[len] = (u_char)byte;
                }
                if (len == 0)
                        return (CMDRTN_USAGE);
        }

        /* Send data */
        sag->sg_len = 3 + hooklen;
        sag->sg_family = AF_NETGRAPH;
        if (sendto(dsock, buf, len, 0, (struct sockaddr *)sag,
            sag->sg_len) < 0) {
                warn("writing to hook \"%s\"", hook);
                return (CMDRTN_ERROR);
        }

        /* Done */
        return (CMDRTN_OK);
}