logresolve.c 10.2 KB
Newer Older
powelld's avatar
powelld committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329
/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * logresolve 2.0
 *
 * Tom Rathborne - tomr uunet.ca - http://www.uunet.ca/~tomr/
 * UUNET Canada, April 16, 1995
 *
 * Rewritten by David Robinson. (drtr ast.cam.ac.uk)
 * Rewritten again, and ported to APR by Colm MacCarthaigh
 *
 * Usage: logresolve [-s filename] [-c] < access_log > new_log
 *
 * Arguments:
 *    -s filename     name of a file to record statistics
 *    -c              check the DNS for a matching A record for the host.
 *
 * Notes:             (For historical interest)
 *
 * To generate meaningful statistics from an HTTPD log file, it's good
 * to have the domain name of each machine that accessed your site, but
 * doing this on the fly can slow HTTPD down.
 *
 * Compiling NCSA HTTPD with the -DMINIMAL_DNS flag turns IP#->hostname
 * resolution off. Before running your stats program, just run your log
 * file through this program (logresolve) and all of your IP numbers will
 * be resolved into hostnames (where possible).
 *
 * logresolve takes an HTTPD access log (in the COMMON log file format,
 * or any other format that has the IP number/domain name as the first
 * field for that matter), and outputs the same file with all of the
 * domain names looked up. Where no domain name can be found, the IP
 * number is left in.
 *
 * To minimize impact on your nameserver, logresolve has its very own
 * internal hash-table cache. This means that each IP number will only
 * be looked up the first time it is found in the log file.
 *
 * The -c option causes logresolve to apply the same check as httpd
 * compiled with -DMAXIMUM_DNS; after finding the hostname from the IP
 * address, it looks up the IP addresses for the hostname and checks
 * that one of these matches the original address.
 */

#include "apr.h"
#include "apr_lib.h"
#include "apr_hash.h"
#include "apr_getopt.h"
#include "apr_strings.h"
#include "apr_file_io.h"
#include "apr_network_io.h"

#if APR_HAVE_STDLIB_H
#include <stdlib.h>
#endif

#define READ_BUF_SIZE  128*1024
#define WRITE_BUF_SIZE 128*1024
#define LINE_BUF_SIZE  128*1024

static apr_file_t *errfile;
static const char *shortname = "logresolve";
static apr_hash_t *cache;

/* Statistics */
static int cachehits = 0;
static int cachesize = 0;
static int entries = 0;
static int resolves = 0;
static int withname = 0;
static int doublefailed = 0;
static int noreverse = 0;

/*
 * prints various statistics to output
 */
#define NL APR_EOL_STR
static void print_statistics (apr_file_t *output)
{
    apr_file_printf(output, "logresolve Statistics:" NL);
    apr_file_printf(output, "Entries: %d" NL, entries);
    apr_file_printf(output, "    With name   : %d" NL, withname);
    apr_file_printf(output, "    Resolves    : %d" NL, resolves);

    if (noreverse) {
        apr_file_printf(output, "    - No reverse : %d" NL,
                        noreverse);
    }

    if (doublefailed) {
        apr_file_printf(output, "    - Double lookup failed : %d" NL,
                        doublefailed);
    }

    apr_file_printf(output, "Cache hits      : %d" NL, cachehits);
    apr_file_printf(output, "Cache size      : %d" NL, cachesize);
}

/*
 * usage info
 */
static void usage(void)
{
    apr_file_printf(errfile,
    "%s -- Resolve IP-addresses to hostnames in Apache log files."           NL
    "Usage: %s [-s STATFILE] [-c]"                                           NL
                                                                             NL
    "Options:"                                                               NL
    "  -s   Record statistics to STATFILE when finished."                    NL
                                                                             NL
    "  -c   Perform double lookups when resolving IP addresses."             NL,
    shortname, shortname);
    exit(1);
}
#undef NL

int main(int argc, const char * const argv[])
{
    apr_file_t * outfile;
    apr_file_t * infile;
    apr_getopt_t * o;
    apr_pool_t * pool;
    apr_pool_t *pline;
    apr_status_t status;
    const char * arg;
    char * stats = NULL;
    char * inbuffer;
    char * outbuffer;
    char * line;
    int doublelookups = 0;

    if (apr_app_initialize(&argc, &argv, NULL) != APR_SUCCESS) {
        return 1;
    }
    atexit(apr_terminate);

    if (argc) {
        shortname = apr_filepath_name_get(argv[0]);
    }

    if (apr_pool_create(&pool, NULL) != APR_SUCCESS) {
        return 1;
    }
    apr_file_open_stderr(&errfile, pool);
    apr_getopt_init(&o, pool, argc, argv);

    while (1) {
        char opt;
        status = apr_getopt(o, "s:c", &opt, &arg);
        if (status == APR_EOF) {
            break;
        }
        else if (status != APR_SUCCESS) {
            usage();
        }
        else {
            switch (opt) {
            case 'c':
                if (doublelookups) {
                    usage();
                }
                doublelookups = 1;
                break;
            case 's':
                if (stats) {
                    usage();
                }
                stats = apr_pstrdup(pool, arg);
                break;
            } /* switch */
        } /* else */
    } /* while */

    apr_file_open_stdout(&outfile, pool);
    apr_file_open_stdin(&infile, pool);

    /* Allocate two new 10k file buffers */
    if (   (outbuffer = apr_palloc(pool, WRITE_BUF_SIZE)) == NULL
        || (inbuffer  = apr_palloc(pool, READ_BUF_SIZE))  == NULL
        || (line      = apr_palloc(pool, LINE_BUF_SIZE))  == NULL) {
        return 1;
    }

    /* Set the buffers */
    apr_file_buffer_set(infile, inbuffer, READ_BUF_SIZE);
    apr_file_buffer_set(outfile, outbuffer, WRITE_BUF_SIZE);

    cache = apr_hash_make(pool);
    if (apr_pool_create(&pline, pool) != APR_SUCCESS) {
        return 1;
    }

    while (apr_file_gets(line, LINE_BUF_SIZE, infile) == APR_SUCCESS) {
        char *hostname;
        char *space;
        apr_sockaddr_t *ip;
        apr_sockaddr_t *ipdouble;
        char dummy[] = " " APR_EOL_STR;

        if (line[0] == '\0') {
            continue;
        }

        /* Count our log entries */
        entries++;

        /* Check if this could even be an IP address */
        if (!apr_isxdigit(line[0]) && line[0] != ':') {
            withname++;
            apr_file_puts(line, outfile);
            continue;
        }

        /* Terminate the line at the next space */
        if ((space = strchr(line, ' ')) != NULL) {
            *space = '\0';
        }
        else {
            space = dummy;
        }

        /* See if we have it in our cache */
        hostname = (char *) apr_hash_get(cache, line, APR_HASH_KEY_STRING);
        if (hostname) {
            apr_file_printf(outfile, "%s %s", hostname, space + 1);
            cachehits++;
            continue;
        }

        /* Parse the IP address */
        status = apr_sockaddr_info_get(&ip, line, APR_UNSPEC, 0, 0, pline);
        if (status != APR_SUCCESS) {
            /* Not an IP address */
            withname++;
            *space = ' ';
            apr_file_puts(line, outfile);
            continue;
        }

        /* This does not make much sense, but historically "resolves" means
         * "parsed as an IP address". It does not mean we actually resolved
         * the IP address into a hostname.
         */
        resolves++;

        /* From here on our we cache each result, even if it was not
         * successful
         */
        cachesize++;

        /* Try and perform a reverse lookup */
        status = apr_getnameinfo(&hostname, ip, 0) != APR_SUCCESS;
        if (status || hostname == NULL) {
            /* Could not perform a reverse lookup */
            *space = ' ';
            apr_file_puts(line, outfile);
            noreverse++;

            /* Add to cache */
            *space = '\0';
            apr_hash_set(cache, line, APR_HASH_KEY_STRING,
                         apr_pstrdup(apr_hash_pool_get(cache), line));
            continue;
        }

        /* Perform a double lookup */
        if (doublelookups) {
            /* Do a forward lookup on our hostname, and see if that matches our
             * original IP address.
             */
            status = apr_sockaddr_info_get(&ipdouble, hostname, ip->family, 0,
                                           0, pline);
            if (status == APR_SUCCESS ||
                memcmp(ipdouble->ipaddr_ptr, ip->ipaddr_ptr, ip->ipaddr_len)) {
                /* Double-lookup failed  */
                *space = ' ';
                apr_file_puts(line, outfile);
                doublefailed++;

                /* Add to cache */
                *space = '\0';
                apr_hash_set(cache, line, APR_HASH_KEY_STRING,
                             apr_pstrdup(apr_hash_pool_get(cache), line));
                continue;
            }
        }

        /* Outout the resolved name */
        apr_file_printf(outfile, "%s %s", hostname, space + 1);

        /* Store it in the cache */
        apr_hash_set(cache, line, APR_HASH_KEY_STRING,
                     apr_pstrdup(apr_hash_pool_get(cache), hostname));

        apr_pool_clear(pline);
    }

    /* Flush any remaining output */
    apr_file_flush(outfile);

    if (stats) {
        apr_file_t *statsfile;
        if (apr_file_open(&statsfile, stats,
                          APR_FOPEN_WRITE | APR_FOPEN_CREATE | APR_FOPEN_TRUNCATE,
                          APR_OS_DEFAULT, pool) != APR_SUCCESS) {
            apr_file_printf(errfile, "%s: Could not open %s for writing.",
                            shortname, stats);
            return 1;
        }
        print_statistics(statsfile);
        apr_file_close(statsfile);
    }

    return 0;
}