experiment5.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <unistd.h>
   4 #include <string.h>
   5
   6 typedef struct line LINE;
   7
   8 struct line {
   9     unsigned long int mac;
  10     unsigned long int ip;
  11     char *fqdn;
  12     LINE *next;
  13 };
  14
  15 LINE *first = NULL;
  16 LINE *last  = NULL;
  17 LINE *array   = NULL;
  18
  19 int listlen = 0;
  20
  21 int add(unsigned long int mac, unsigned long int ip, char *fqdn) {
  22     LINE *new = malloc(sizeof(LINE));
  23     new->mac = mac;
  24     new->ip  = ip;
  25     new->fqdn = fqdn;
  26     new->next = NULL;
  27
  28     if (!first)
  29         first = new;
  30     else
  31         last->next = new;
  32
  33     last = new;
  34
  35     return 0;
  36 }
  37
  38 int add_line(char *line) {
  39     if (strncmp(line, "dhcp-host=", 10) == 0 &&
  40                 line[12] == ':' && line[15] == ':' && line[18] == ':' && line[21] == ':' && line[24] == ':' &&
  41                 line[27] == ',') {
  42         char *ip, *nextip;
  43         char macstring[4];
  44         LINE *new = malloc(sizeof(LINE));
  45
  46         if (new == NULL) return -1;
  47
  48         listlen++;
  49         macstring[2] = '\0';
  50         macstring[3] = '\0';
  51
  52         new->mac = 0;
  53         new->ip  = 0;
  54         new->next= NULL;
  55
  56         strncpy(macstring, &line[19], 2);
  57         new->mac += (strtoul(macstring, NULL, 16) * (unsigned long int)(256 * 256));
  58         strncpy(macstring, &line[22], 2);
  59         new->mac += (strtoul(macstring, NULL, 16) * (unsigned long int)(256));
  60         strncpy(macstring, &line[25], 2);
  61         new->mac += (strtoul(macstring, NULL, 16));
  62
  63         ip = strchr(&line[28], ',');
  64         new->fqdn = strndup(&line[28], ip - &line[28]);
  65         ip++;
  66
  67         macstring[1] = '\0'; macstring[2] = '\0';
  68         strncpy(macstring, ip, (nextip = strchr(ip, '.')) - ip);
  69         new->ip += (strtoul(macstring, NULL, 10) * (unsigned long int)(256 * 256 * 256));
  70 //        printf("%s %lu\n",  macstring, new->ip);
  71         ip = nextip + 1;
  72
  73         macstring[1] = '\0'; macstring[2] = '\0';
  74         strncpy(macstring, ip, (nextip = strchr(ip, '.')) - ip);
  75         new->ip += (strtoul(macstring, NULL, 10) * (unsigned long int)(256 * 256));
  76 //        printf("%s %lu\n",  macstring, (strtoul(macstring, NULL, 10) * (unsigned long int)(256 * 256)));
  77         ip = nextip + 1;
  78
  79         macstring[1] = '\0'; macstring[2] = '\0';
  80         strncpy(macstring, ip, (nextip = strchr(ip, '.')) - ip);
  81         new->ip += (strtoul(macstring, NULL, 10) * (unsigned long int)(256));
  82 //        printf("%s %lu\n",  macstring, strtoul(macstring, NULL, 10) * (unsigned long int)(256));
  83         ip = nextip + 1;
  84
  85         macstring[1] = '\0'; macstring[2] = '\0';
  86         strncpy(macstring, ip, (nextip = strchr(ip, ',')) - ip);
  87         new->ip += (strtoul(macstring, NULL, 10));
  88 //        printf("%s %lu\n",  macstring, strtoul(macstring, NULL, 10));
  89
  90 //        printf("%06lX %s %lu %lu\n", new->mac, new->fqdn, new->mac, new->ip);
  91 //            dhcp-host=00:1E:C9:B3:B3:85,xen001.xen,172.16.103.1,24h
  92 //
  93
  94         if (!first)
  95             first = new;
  96         else
  97             last->next = new;
  98
  99         last = new;
 100
 101         return 0;
 102     }
 103
 104     return -1;
 105 }
 106
 107 int print_forget() {
 108     LINE *step = first;
 109     while (step) {
 110         int a, b, c, d;
 111         char mac[9];
 112         mac[8] = '\0';
 113         LINE *this = step;
 114
 115         snprintf(mac, 8, "%06lX", this->mac);
 116         strncpy(&mac[6], &mac[4], 2);
 117         strncpy(&mac[3], &mac[2], 2);
 118         mac[2] = ':';
 119         mac[5] = ':';
 120
 121         ldiv_t ip = ldiv(this->ip, (256*256*256));
 122         a = ip.quot;
 123         ip = ldiv(ip.rem, (256*256));
 124         b = ip.quot;
 125         ip = ldiv(ip.rem, (256));
 126         c = ip.quot;
 127         d = ip.rem;
 128
 129         printf("dhcp-host=00:16:3E:%s,%s,%d.%d.%d.%d,24h\n", mac, this->fqdn, a, b, c, d);
 130
 131
 132         free(this->fqdn);
 133
 134         step = this->next;
 135         free(this);
 136     }
 137
 138     return 0;
 139 }
 140
 141 int ll_array() {
 142     int i = 0;
 143     array = malloc(sizeof(LINE) * listlen);
 144
 145     LINE *step = first;
 146     while (step) {
 147         array[i].mac  = step->mac;
 148         array[i].ip  = step->ip;
 149         array[i].fqdn = step->fqdn;
 150         step = step->next;
 151         i++;
 152     }
 153
 154     return 0;
 155 }
 156
 157 static int bymac(const void *a, const void *b) {
 158     LINE *temp1 = (LINE *) a;
 159     LINE *temp2 = (LINE *) b;
 160
 161     return temp1->mac - temp2->mac;
 162 }
 163
 164 static int byip(const void *a, const void *b) {
 165     LINE *temp1 = (LINE *) a;
 166     LINE *temp2 = (LINE *) b;
 167
 168     return temp1->ip - temp2->ip;
 169 }
 170
 171 static unsigned long int nextmac() {
 172     int i;
 173     for (i = 0; i < (listlen - 1); i++) {
 174         if (array[i+1].mac != array[i].mac + 1) return array[i].mac + 1;
 175     }
 176     return array[listlen - 1].mac + 1;
 177 }
 178
 179 static unsigned long int nextip() {
 180     int i;
 181     for (i = 0; i < (listlen - 1); i++) {
 182         if (array[i+1].ip != array[i].ip + 1) return array[i].ip + 1;
 183     }
 184     return array[listlen - 1].ip + 1;
 185 }
 186
 187 int main() {
 188     unsigned long int new_mac, new_ip;
 189     char line[1024];
 190     FILE *fd;
 191     if ((fd = fopen("/mnt/netapp/ipservices/dv28.conf", "r")) != NULL) {
 192         while (!feof(fd)) {
 193             if (fgets(line, 1024, fd) > 0)
 194                 add_line(line);
 195         }
 196         fclose(fd);
 197     }
 198
 199     if (listlen > 0) {
 200         ll_array();
 201
 202         qsort(array, listlen, sizeof(LINE), bymac);
 203         new_mac = nextmac();
 204
 205         qsort(array, listlen, sizeof(LINE), byip);
 206         new_ip = nextip();
 207     }
 208
 209     add(new_mac, new_ip, strdup("test.xen"));
 210
 211     print_forget();
 212
 213     free(array);
 214
 215     return 0;
 216 }