/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON 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 ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#) Copyright (c) 1983, 1993 The Regents of the University of California.  All rights reserved.
 * @(#)logger.c 8.1 (Berkeley) 6/6/93
 * $FreeBSD: src/usr.bin/logger/logger.c,v 1.5.2.3 2001/09/06 17:38:57 ru Exp $
 * $DragonFly: src/usr.bin/logger/logger.c,v 1.4 2005/02/25 18:08:05 liamfoy Exp $
 */

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

#include <ctype.h>
#include <err.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define SYSLOG_NAMES
#include <syslog.h>

static int      decode(const char *, CODE *);
static int      pencode(char *);
static void     logmessage(int, const char *, const char *);
static void     usage(void);

struct socks {
    int sock;
    int addrlen;
    struct sockaddr_storage addr;
};

#ifdef INET6
int     family = PF_UNSPEC;     /* protocol family (IPv4, IPv6 or both) */
#else
int     family = PF_INET;       /* protocol family (IPv4 only) */
#endif
int     send_to_all = 0;        /* send message to all IPv4/IPv6 addresses */

/*
 * logger -- read and log utility
 *
 *      Reads from an input and arranges to write the result on the system
 *      log.
 */
int
main(int argc, char **argv)
{
        int ch, logflags, pri;
        char *tag, *host, buf[1024];

        tag = NULL;
        host = NULL;
        pri = LOG_USER | LOG_NOTICE;
        logflags = 0;
        unsetenv("TZ");
        while ((ch = getopt(argc, argv, "46Af:h:ip:st:")) != -1)
                switch(ch) {
                case '4':
                        family = PF_INET;
                        break;
#ifdef INET6
                case '6':
                        family = PF_INET6;
                        break;
#endif
                case 'A':
                        send_to_all++;
                        break;
                case 'f':               /* file to log */
                        if (freopen(optarg, "r", stdin) == NULL)
                                err(1, "%s", optarg);
                        break;
                case 'h':               /* hostname to deliver to */
                        host = optarg;
                        break;
                case 'i':               /* log process id also */
                        logflags |= LOG_PID;
                        break;
                case 'p':               /* priority */
                        pri = pencode(optarg);
                        break;
                case 's':               /* log to standard error */
                        logflags |= LOG_PERROR;
                        break;
                case 't':               /* tag */
                        tag = optarg;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        /* setup for logging */
        openlog(tag ? tag : getlogin(), logflags, 0);
        fclose(stdout);

        /* log input line if appropriate */
        if (argc > 0) {
                char *p, *endp;
                size_t len;

                for (p = buf, endp = buf + sizeof(buf) - 2; *argv;) {
                        len = strlen(*argv);
                        if (p + len > endp && p > buf) {
                                logmessage(pri, host, buf);
                                p = buf;
                        }
                        if (len > sizeof(buf) - 1)
                                logmessage(pri, host, *argv++);
                        else {
                                if (p != buf)
                                        *p++ = ' ';
                                bcopy(*argv++, p, len);
                                *(p += len) = '\0';
                        }
                }
                if (p != buf)
                        logmessage(pri, host, buf);
        } else
                while (fgets(buf, sizeof(buf), stdin) != NULL)
                        logmessage(pri, host, buf);
        exit(0);
}

/*
 *  Send the message to syslog, either on the local host, or on a remote host
 */
static void 
logmessage(int pri, const char *host, const char *buf)
{
        static struct socks *socks;
        static int nsock = 0;
        struct addrinfo hints, *res, *r;
        char *line;
        int maxs, len, sock, error, i, lsent = 0;

        if (host == NULL) {
                syslog(pri, "%s", buf);
                return;
        }

        if (nsock <= 0) {       /* set up socket stuff */
                /* resolve hostname */
                memset(&hints, 0, sizeof(hints));
                hints.ai_family = family;
                hints.ai_socktype = SOCK_DGRAM;
                error = getaddrinfo(host, "syslog", &hints, &res);
                if (error == EAI_SERVICE) {
                        warnx ("syslog/udp: unknown service");  /* not fatal */
                        error = getaddrinfo(host, "514", &hints, &res);
                }
                if (error)
                        errx(1, "%s: %s", gai_strerror(error), host);
                /* count max number of sockets we may open */
                for (maxs = 0, r = res; r; r = r->ai_next, maxs++);
                socks = malloc(maxs * sizeof(struct socks));
                if (!socks)
                        err(1, "couldn't allocate memory for sockets");
                for (r = res; r; r = r->ai_next) {
                        sock = socket(r->ai_family, r->ai_socktype,
                                      r->ai_protocol);
                        if (sock < 0)
                                continue;
                        memcpy(&socks[nsock].addr, r->ai_addr, r->ai_addrlen);
                        socks[nsock].addrlen = r->ai_addrlen;
                        socks[nsock++].sock = sock;
                }
                freeaddrinfo(res);
                if (nsock <= 0)
                        errx(1, "socket");
        }

        if ((len = asprintf(&line, "<%d>%s", pri, buf)) == -1)
                errx(1, "asprintf");

        for (i = 0; i < nsock; ++i) {
                lsent = sendto(socks[i].sock, line, len, 0,
                               (struct sockaddr *)&socks[i].addr,
                               socks[i].addrlen);
                if (lsent == len && !send_to_all)
                        break;
        }
        if (lsent != len)
                warnx("sendmsg");

        free(line);
}

/*
 *  Decode a symbolic name to a numeric value
 */
static int
pencode(char *s)
{
        char *save;
        int fac, lev;

        for (save = s; *s && *s != '.'; ++s);
        if (*s) {
                *s = '\0';
                fac = decode(save, facilitynames);
                if (fac < 0)
                        errx(1, "unknown facility name: %s", save);
                *s++ = '.';
        }
        else {
                fac = 0;
                s = save;
        }
        lev = decode(s, prioritynames);
        if (lev < 0)
                errx(1, "unknown priority name: %s", save);
        return ((lev & LOG_PRIMASK) | (fac & LOG_FACMASK));
}

int
decode(const char *name, CODE *codetab)
{
        CODE *c;

        if (isdigit(*name))
                return (atoi(name));

        for (c = codetab; c->c_name; c++)
                if (!strcasecmp(name, c->c_name))
                        return (c->c_val);

        return (-1);
}

static void
usage(void)
{
        fprintf(stderr, "usage: %s\n",
            "logger [-46Ais] [-f file] [-h host] [-p pri] [-t tag] [message ...]");
        exit(1);
}