/*
 * Copyright 2016 Google Inc. All rights reserved.
 *
 * Licensed 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.
 */

#include <getopt.h>
#include <inttypes.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>


struct string_match {
  char *vendor_class;
  char *species;
};

/* Function generated by gperf for the exact_match lookup table. */
extern const struct string_match *exact_match (const char *str,
    unsigned int len);


struct string_match substring_matches[] = {
  /*
   * Examples:
   *   AastraIPPhone55i
   *   AastraIPPhone57iCT
   *   AastraIPPhone6737i
   */
  {"AastraIPPhone", "Aastra IP Phone"},

  /* Examples:
   * AXIS,Network Camera,M3006,5.40.13
   * AXIS,Network Camera,P3346,5.20.1
   * AXIS,Thermal Network Camera,Q1931-E,5.55.4.1
   */
  {"AXIS,Network Camera", "AXIS Network Camera"},
  {"AXIS,Thermal Network Camera", "AXIS Network Camera"},

  /* Examples:
   * Canon MF620C Series
   */
  {"Canon MF", "Canon Printer"},

  /* Examples:
   * Cisco AP c1200
   * Cisco AP c1240
   */
  {"Cisco AP", "Cisco Wifi AP"},

  /* Examples:
   *   Cisco Systems, Inc. IP Phone CP-7961G
   *   Cisco Systems, Inc. IP Phone CP-8861
   */
  {"Cisco Systems, Inc. IP Phone", "Cisco IP Phone"},

  /* Examples:
   *   Cisco SPA504G
   *   Cisco SPA525G2
   *   CISCO SPA112
   *   ATA186-H6.0|V3.2.0|B041111A
   */
  {"Cisco SPA", "Cisco IP Phone"},
  {"CISCO SPA", "Cisco IP Phone"},
  {"ATA186", "Cisco IP Phone"},

  /* Examples:
   * CPQRIB3
   */
  {"CPQRIB", "Compaq Remote Insight"},

  /* Examples:
   * Dell Color MFP E525w
   */
  {"Dell Color MFP", "Dell Printer"},

  /* Examples:
   * digium_D40_1_4_2_0_63880
   */
  {"digium", "Digium IP Phone"},

  /* Examples:
   * FortiAP-FP321C-AC-Discovery
   * FortiAP-FP221B-AC-Discovery
   * FortiAP-FP321C
   * FortiWiFi-60D-POE
   */
  {"FortiAP", "Fortinet Wifi AP"},
  {"FortiWiFi", "Fortinet Wifi AP"},

  /* Examples:
   * Grandstream GXP1405 dslforum.org
   * Grandstream GXP2124 dslforum.org
   * Grandstream GXV3275 dslforum.org
   * Grandstream HT702 dslforum.org
   */
  {"Grandstream GXP", "Grandstream IP Phone"},
  {"Grandstream GXV", "Grandstream IP Phone"},
  {"Grandstream HT", "Grandstream VoIP adapter"},

  /* Examples:
   * iPECS IP Edge 5000i-24G
   */
  {"iPECS IP Edge", "iPECS IP PHONE"},

  /* Examples:
   * Juniper-ex2200-c-12p-2g
   */
  {"Juniper-ex", "Juniper router"},

  /* Examples:
   *   LINKSYS SPA-922
   *   LINKSYS SPA-942
   */
  {"LINKSYS SPA", "Linksys IP Phone"},

  /* Examples:
   * MotorolaAP.AP7131
   */
  {"MotorolaAP", "Motorola Wifi AP"},

  /* Examples:
   * NECDT700
   */
  {"NECDT", "NEC IP Phone"},

  /* Examples:
   *   6=qPolycomSoundPointIP-SPIP_1234567-12345-001
   *   6=tPolycomSoundStationIP-SSIP_12345678-12345-001
   */
  {"PolycomSoundPointIP", "Polycom IP Phone"},

  /* Examples:
   *   Polycom-SPIP335
   *   Polycom-SPIP550
   *   Polycom-SSIP7000
   *   Polycom-VVX310
   *   Polycom-VVX500
   *   Polycom-VVX600
   */
  {"Polycom-SPIP", "Polycom IP Phone"},
  {"Polycom-SSIP", "Polycom IP Phone"},
  {"Polycom-VVX", "Polycom IP Phone"},

  /* Examples:
   * Rabbit2000-TCPIP:Z-World:Testfoo:1.1.3
   * Rabbit-TCPIP:Z-World:DHCP-Test:1.2.0
   */
  {"Rabbit-TCPIP", "Rabbit Microcontroller"},
  {"Rabbit2000-TCPIP", "Rabbit Microcontroller"},

  /* Examples:
   * ReadyNet_WRT500
   */
  {"ReadyNet_WRT", "ReadyNet Wifi AP"},

  /* Examples:
   * SAMSUNG SCX-6x45
   */
  {"SAMSUNG SCX", "Samsung Network MFP"},

  /* Examples:
   * SF200-24P
   * SG 200-08
   * SG 200-26
   * SG 300-10
   * SG 300-20
   * SG200-26
   * SG200-50P
   * SG300-10
   */
  {"SF200", "Cisco Managed Switch"},
  {"SG 200", "Cisco Managed Switch"},
  {"SG200", "Cisco Managed Switch"},
  {"SG 300", "Cisco Managed Switch"},
  {"SG300", "Cisco Managed Switch"},

  /* Examples:
   * snom-m3-SIP/02.11//18-Aug-10 15:36
   * snom320
   * snom710
   */
  {"snom", "Snom IP Phone"},

  /* Examples:
   * telsey-stb-f8
   */
  {"telsey-stb", "Telsey Media Player"},

  {NULL, NULL}
};


/* Copy a string with no funny schtuff allowed; only alphanumerics + space. */
static void no_mischief_strncpy(char *dst, const char *src, size_t n)
{
  size_t i;
  for (i = 0; i < n; ++i) {
    unsigned char s = src[i];
    int is_lower = (s >= 'a' && s <= 'z');
    int is_upper = (s >= 'A' && s <= 'Z');
    int is_digit = (s >= '0' && s <= '9');
    if (s == '\0') {
      dst[i] = '\0';
      break;
    } else if (is_lower || is_upper || is_digit) {
      dst[i] = s;
    } else if (s == ' ' || s == '\t') {
      dst[i] = ' ';
    } else {
      dst[i] = '_';
    }
  }

  dst[n - 1] = '\0';
}

/*
 * Check for vendor options pattern populated by a number of
 * printer manufacturers:
 *
 *   Mfg=DELL;Typ=Printer;Mod=Dell 2330dn Laser Printer;Ser=0123AB5;
 *   Mfg=FujiXerox;Typ=AIO;Mod=WorkCentre 6027;Ser=P1A234567
 *   Mfg=Hewlett Packard;Typ=Printer;Mod=HP LaserJet 400 M401n;Ser=ABCDE01234;
 *   mfg=Xerox;typ=MFP;mod=WorkCentre 3220;ser=ABC012345;loc=
 */
int check_for_printer(const char *vendor_class, char *species,
    size_t species_len)
{
  regex_t r_vendor, r_type, r_model;
  regmatch_t match[2];
  char *vendor = NULL, *type = NULL, *model = NULL;
  int rc = 1;

  if (regcomp(&r_vendor, "mfg=([^;]+)", REG_EXTENDED | REG_ICASE) ||
      regcomp(&r_type, "typ=([^;]+)", REG_EXTENDED | REG_ICASE) ||
      regcomp(&r_model, "mod=([^;]+)", REG_EXTENDED | REG_ICASE)) {
    fprintf(stderr, "%s: regcomp failed!\n", __FUNCTION__);
    exit(1);
  }

  if (regexec(&r_vendor, vendor_class, 2, match, 0) == 0) {
    int len = match[1].rm_eo - match[1].rm_so;
    vendor = strndup(vendor_class + match[1].rm_so, len);
  }

  if (regexec(&r_type, vendor_class, 2, match, 0) == 0) {
    int len = match[1].rm_eo - match[1].rm_so;
    type = strndup(vendor_class + match[1].rm_so, len);
  }

  if (regexec(&r_model, vendor_class, 2, match, 0) == 0) {
    int len = match[1].rm_eo - match[1].rm_so;
    model = strndup(vendor_class + match[1].rm_so, len);
  }

  if (vendor && type) {
    char buf[128];
    snprintf(buf, sizeof(buf), "%s %s", vendor, type);
    no_mischief_strncpy(species, buf, species_len);
    rc = 0;
  } else if (model) {
    no_mischief_strncpy(species, model, species_len);
    rc = 0;
  }

  if (vendor) free(vendor);
  if (type) free(type);
  if (model) free(model);

  return(rc);
}

/*
 * Check a few patterns from common vendors with lots of model
 * numbers.
 */
int check_specials(const char *vendor_class, char *species,
    size_t species_len)
{
  regex_t r_dellprinter, r_grandstream;

  /*
   * Dell printers. Examples:
   * Dell C1760nw Color Printer
   * Dell C2660dn Color Laser
   * Dell 2155cn Color MFP
   */
  if (regcomp(&r_dellprinter, "^Dell \\S+ Color (Printer|Laser|MFP)",
        REG_EXTENDED | REG_ICASE | REG_NOSUB)) {
    fprintf(stderr, "%s: regcomp failed!\n", __FUNCTION__);
    exit(1);
  }
  if (regexec(&r_dellprinter, vendor_class, 0, NULL, 0) == 0) {
    snprintf(species, species_len, "Dell Printer");
    return(0);
  }

  /*
   * Grandstream Voice over IP adapters. Examples:
   * HT500 dslforum.org
   * HT7XX dslforum.org
   */
  if (regcomp(&r_grandstream, "^HT.* dslforum.org",
        REG_EXTENDED | REG_ICASE | REG_NOSUB)) {
    fprintf(stderr, "%s: regcomp failed!\n", __FUNCTION__);
    exit(1);
  }
  if (regexec(&r_grandstream, vendor_class, 0, NULL, 0) == 0) {
    snprintf(species, species_len, "Grandstream VoIP adapter");
    return(0);
  }

  /*
   * Grandstream IP phones. Examples:
   * DP7XX dslforum.org
   */
  if (regcomp(&r_grandstream, "^DP.* dslforum.org",
        REG_EXTENDED | REG_ICASE | REG_NOSUB)) {
    fprintf(stderr, "%s: regcomp failed!\n", __FUNCTION__);
    exit(1);
  }
  if (regexec(&r_grandstream, vendor_class, 0, NULL, 0) == 0) {
    snprintf(species, species_len, "Grandstream IP phone");
    return(0);
  }

  return(1);
}


int lookup_vc(const char *vendor_class, char *species, size_t species_len)
{
  const struct string_match *p;
  int slen = strlen(vendor_class);

  if ((p = exact_match(vendor_class, slen)) != NULL) {
    no_mischief_strncpy(species, p->species, species_len);
    return(0);
  }

  p = &substring_matches[0];
  while (p->vendor_class != NULL) {
    if (strstr(vendor_class, p->vendor_class) != NULL) {
      no_mischief_strncpy(species, p->species, species_len);
      return(0);
    }
    p++;
  }

  if (check_for_printer(vendor_class, species, species_len) == 0) {
    return(0);
  }

  if (check_specials(vendor_class, species, species_len) == 0) {
    return(0);
  }

  return(1);
}


void usage(const char *progname)
{
  fprintf(stderr, "usage: %s -v vendor_string -l label\n", progname);
  exit(1);
}


int main(int argc, char **argv)
{
  struct option long_options[] = {
    {"label",   required_argument, 0, 'l'},
    {"vendor",  required_argument, 0, 'v'},
    {0,         0,                 0, 0},
  };
  int c;
  const char *label = NULL;
  const char *vendor = NULL;
  char species[80];

  setlinebuf(stdout);
  alarm(30);
  while ((c = getopt_long(argc, argv, "l:v:", long_options, NULL)) != -1) {
    switch (c) {
    case 'l':
      label = optarg;
      break;
    case 'v':
      vendor = optarg;
      break;
    default:
      usage(argv[0]);
    }
  }

  if (optind < argc || vendor == NULL || label == NULL)
    usage(argv[0]);

  memset(species, 0, sizeof(species));
  if (lookup_vc(vendor, species, sizeof(species)) == 0) {
    printf("dhcpv %s %s\n", label, species);
  }
  exit(0);
}