src/servmgmt.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2011 Daniel Borkmann.
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #include <stdio.h>
   9 #include <stdint.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <limits.h>
  13
  14 #include "die.h"
  15 #include "compiler.h"
  16 #include "locking.h"
  17 #include "xmalloc.h"
  18 #include "curvetun.h"
  19 #include "xstring.h"
  20 #include "curve.h"
  21 #include "servmgmt.h"
  22 #include "crypto_box_curve25519xsalsa20poly1305.h"
  23 #include "crypto_auth_hmacsha512256.h"
  24
  25 #define crypto_box_pub_key_size crypto_box_curve25519xsalsa20poly1305_PUBLICKEYBYTES
  26
  27 /* Config line format: alias;serverip|servername;port;udp|tcp;pubkey\n */
  28
  29 struct server_store {
  30         char alias[256];
  31         char host[256];
  32         char port[6]; /* 5 + \0 */
  33         int udp;
  34         unsigned char publickey[crypto_box_pub_key_size];
  35         struct curve25519_proto proto_inf;
  36         unsigned char auth_token[crypto_auth_hmacsha512256_KEYBYTES];
  37         struct server_store *next;
  38 };
  39
  40 static struct server_store *store = NULL;
  41
  42 static struct server_store *selected = NULL;
  43
  44 static struct rwlock store_lock;
  45
  46 static struct server_store *server_store_alloc(void)
  47 {
  48         return xzmalloc(sizeof(struct server_store));
  49 }
  50
  51 static void server_store_free(struct server_store *ss)
  52 {
  53         if (!ss)
  54                 return;
  55         memset(ss, 0, sizeof(struct server_store));
  56         xfree(ss);
  57 }
  58
  59 void parse_userfile_and_generate_serv_store_or_die(char *homedir)
  60 {
  61         FILE *fp;
  62         char path[PATH_MAX], buff[1024], *alias, *host, *port, *udp, *key;
  63         unsigned char pkey[crypto_box_pub_key_size];
  64         int line = 1, __udp = 0, ret;
  65         struct server_store *elem;
  66
  67         memset(path, 0, sizeof(path));
  68         slprintf(path, sizeof(path), "%s/%s", homedir, FILE_SERVERS);
  69
  70         rwlock_init(&store_lock);
  71         rwlock_wr_lock(&store_lock);
  72
  73         fp = fopen(path, "r");
  74         if (!fp)
  75                 panic("Cannot open server file!\n");
  76         memset(buff, 0, sizeof(buff));
  77
  78         /* TODO: this is huge crap. needs to be rewritten! */
  79         while (fgets(buff, sizeof(buff), fp) != NULL) {
  80                 buff[sizeof(buff) - 1] = 0;
  81                 /* A comment. Skip this line */
  82                 if (buff[0] == '#' || buff[0] == '\n') {
  83                         memset(buff, 0, sizeof(buff));
  84                         line++;
  85                         continue;
  86                 }
  87                 alias = skips(buff);
  88                 host = alias;
  89                 while (*host != ';' &&
  90                        *host != '\0' &&
  91                        *host != ' ' &&
  92                        *host != '\t')
  93                         host++;
  94                 if (*host != ';')
  95                         panic("Parse error! No alias found in l.%d!\n", line);
  96                 *host = '\0';
  97                 host++;
  98                 if (*host == '\n')
  99                         panic("Parse error! No host found in l.%d!\n", line);
 100                 port = host;
 101                 while (*port != ';' &&
 102                        *port != '\0' &&
 103                        *port != ' ' &&
 104                        *port != '\t')
 105                         port++;
 106                 if (*port != ';')
 107                         panic("Parse error! No host found in l.%d!\n", line);
 108                 *port = '\0';
 109                 port++;
 110                 if (*port == '\n')
 111                         panic("Parse error! No port found in l.%d!\n", line);
 112                 udp = port;
 113                 while (*udp != ';' &&
 114                        *udp != '\0' &&
 115                        *udp != ' ' &&
 116                        *udp != '\t')
 117                         udp++;
 118                 if (*udp != ';')
 119                         panic("Parse error! No port found in l.%d!\n", line);
 120                 *udp = '\0';
 121                 udp++;
 122                 if (*udp == '\n')
 123                         panic("Parse error! No udp|tcp found in l.%d!\n", line);
 124                 if (udp[0] == 'u' && udp[1] == 'd' && udp[2] == 'p')
 125                         __udp = 1;
 126                 else if (udp[0] == 't' && udp[1] == 'c' && udp[2] == 'p')
 127                         __udp = 0;
 128                 else
 129                         panic("Parse error! No udp|tcp found in l.%d!\n", line);
 130                 udp += 3;
 131                 if (*udp != ';')
 132                         panic("Parse error! No key found in l.%d!\n", line);
 133                 *udp = '\0';
 134                 udp++;
 135                 if (*udp == '\n')
 136                         panic("Parse error! No key found in l.%d!\n", line);
 137                 key = udp;
 138                 key[strlen(key) - 1] = 0;
 139                 memset(pkey, 0, sizeof(pkey));
 140                 if (!curve25519_pubkey_hexparse_32(pkey, sizeof(pkey),
 141                                                    key, strlen(key)))
 142                         panic("Parse error! No key found in l.%d!\n", line);
 143
 144                 if (strlen(alias) + 1 > sizeof(elem->alias))
 145                         panic("Alias too long in l.%d!\n", line);
 146                 if (strlen(host) + 1 > sizeof(elem->host))
 147                         panic("Host too long in l.%d!\n", line);
 148                 if (strlen(port) + 1 > sizeof(elem->port))
 149                         panic("Port too long in l.%d!\n", line);
 150                 if (strstr(alias, " ") || strstr(alias, "\t"))
 151                         panic("Alias consists of whitespace in l.%d!\n", line);
 152                 if (strstr(host, " ") || strstr(host, "\t"))
 153                         panic("Host consists of whitespace in l.%d!\n", line);
 154                 if (strstr(port, " ") || strstr(port, "\t"))
 155                         panic("Port consists of whitespace in l.%d!\n", line);
 156
 157                 elem = server_store_alloc();
 158                 elem->next = store;
 159                 elem->udp = __udp;
 160                 strlcpy(elem->alias, alias, sizeof(elem->alias));
 161                 strlcpy(elem->host, host, sizeof(elem->host));
 162                 strlcpy(elem->port, port, sizeof(elem->port));
 163                 memcpy(elem->publickey, pkey, sizeof(elem->publickey));
 164                 memcpy(elem->auth_token, elem->publickey, sizeof(elem->auth_token));
 165                 ret = curve25519_proto_init(&elem->proto_inf,
 166                                             elem->publickey,
 167                                             sizeof(elem->publickey),
 168                                             homedir, 0);
 169                 if (ret)
 170                         panic("Cannot init curve25519 proto on server!\n");
 171                 store = elem;
 172                 memset(buff, 0, sizeof(buff));
 173                 line++;
 174         }
 175
 176         fclose(fp);
 177         if (store == NULL)
 178                 panic("No registered servers found!\n");
 179         rwlock_unlock(&store_lock);
 180 }
 181
 182 void dump_serv_store(void)
 183 {
 184         int i;
 185         struct server_store *elem;
 186
 187         rwlock_rd_lock(&store_lock);
 188         elem = store;
 189         while (elem) {
 190                 printf("[%s] -> %s:%s via %s -> ", elem->alias,
 191                        elem->host, elem->port,
 192                        elem->udp ? "udp" : "tcp");
 193                 for (i = 0; i < sizeof(elem->publickey); ++i)
 194                         if (i == (sizeof(elem->publickey) - 1))
 195                                 printf("%02x\n", (unsigned char)
 196                                        elem->publickey[i]);
 197                         else
 198                                 printf("%02x:", (unsigned char)
 199                                        elem->publickey[i]);
 200                 elem = elem->next;
 201         }
 202         rwlock_unlock(&store_lock);
 203 }
 204
 205 void destroy_serv_store(void)
 206 {
 207         struct server_store *elem, *nelem = NULL;
 208
 209         rwlock_wr_lock(&store_lock);
 210         selected = NULL;
 211         elem = store;
 212         while (elem) {
 213                 nelem = elem->next;
 214                 elem->next = NULL;
 215                 server_store_free(elem);
 216                 elem = nelem;
 217         }
 218         rwlock_unlock(&store_lock);
 219         rwlock_destroy(&store_lock);
 220 }
 221
 222 void get_serv_store_entry_by_alias(char *alias, size_t len,
 223                                    char **host, char **port, int *udp)
 224 {
 225         struct server_store *elem;
 226
 227         rwlock_rd_lock(&store_lock);
 228         elem = store;
 229         if (!alias) {
 230                 while (elem && elem->next)
 231                         elem = elem->next;
 232                 if (elem) {
 233                         (*host) = elem->host;
 234                         (*port) = elem->port;
 235                         (*udp) = elem->udp;
 236                         selected = elem;
 237                 } else {
 238                         rwlock_unlock(&store_lock);
 239                         goto nothing;
 240                 }
 241         } else {
 242                 while (elem) {
 243                         if (!strncmp(elem->alias, alias,
 244                                      min(len, strlen(elem->alias) + 1)))
 245                                 break;
 246                         elem = elem->next;
 247                 }
 248                 if (elem) {
 249                         (*host) = elem->host;
 250                         (*port) = elem->port;
 251                         (*udp) = elem->udp;
 252                         selected = elem;
 253                 } else {
 254                         rwlock_unlock(&store_lock);
 255                         goto nothing;
 256                 }
 257         }
 258         rwlock_unlock(&store_lock);
 259         return;
 260 nothing:
 261         (*host) = NULL;
 262         (*port) = NULL;
 263         (*udp) = -1;
 264 }
 265
 266 struct curve25519_proto *get_serv_store_entry_proto_inf(void)
 267 {
 268         struct curve25519_proto *ret = NULL;
 269         rwlock_rd_lock(&store_lock);
 270         if (selected)
 271                 ret = &selected->proto_inf;
 272         rwlock_unlock(&store_lock);
 273         return ret;
 274 }
 275
 276 unsigned char *get_serv_store_entry_auth_token(void)
 277 {
 278         unsigned char *ret = NULL;
 279         rwlock_rd_lock(&store_lock);
 280         if (selected)
 281                 ret = selected->auth_token;
 282         rwlock_unlock(&store_lock);
 283         return ret;
 284 }
 285