aboutsummaryrefslogtreecommitdiff
path: root/toys/pending/arp.c
blob: 7e7b8668adfb8612cda29fd13f218739201536b8 (plain)
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
/* arp.c - manipulate the system ARP cache
 *
 * Copyright 2014 Sandeep Sharma <sandeep.jack2756@gmail.com>
 * Copyright 2014 Kyungwan Han <asura321@gamil.com>
 * No Standard 

USE_ARP(NEWTOY(arp, "vi:nDsdap:A:H:[+Ap][!sd]", TOYFLAG_USR|TOYFLAG_BIN))

config ARP
  bool "arp"
  default n
  help
    Usage: arp 
    [-vn] [-H HWTYPE] [-i IF] -a [HOSTNAME]
    [-v]              [-i IF] -d HOSTNAME [pub]
    [-v]  [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [temp]
    [-v]  [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [netmask MASK] pub
    [-v]  [-H HWTYPE] [-i IF] -Ds HOSTNAME IFACE [netmask MASK] pub

    Manipulate ARP cache

    -a    Display (all) hosts
    -s    Set new ARP entry
    -d    Delete a specified entry
    -v    Verbose
    -n    Don't resolve names
    -i IF Network interface
    -D    Read <hwaddr> from given device
    -A,-p AF  Protocol family
    -H    HWTYPE Hardware address type

*/

#define FOR_arp
#include "toys.h"
#include <net/if_arp.h>

GLOBALS(
    char *hw_type;
    char *af_type_A;
    char *af_type_p;
    char *interface;
    
    int sockfd;
    char *device;
)

struct arpreq req; //Global request structure 

struct type {
  char *name;
  int val;
};

struct type hwtype[] = {
  {"ether", ARPHRD_ETHER }, 
  {"loop" ,ARPHRD_LOOPBACK},
  {"ppp" ,ARPHRD_PPP},
  {"infiniband" ,ARPHRD_INFINIBAND},
  {NULL, -1},
};

struct type aftype[] = {
  {"inet", AF_INET }, 
  {"inet6" ,AF_INET6},
  {"unspec" ,AF_UNSPEC},
  {NULL, -1},
};

struct type flag_type[] = {
  {"PERM", ATF_PERM }, 
  {"PUB" ,ATF_PUBL},
  {"DONTPUB" ,ATF_DONTPUB},
  {"TRAIL" ,ATF_USETRAILERS},
  {NULL, -1},
};

static int get_index(struct type arr[], char *name)
{
  int i;
  
  for (i = 0; arr[i].name; i++) 
    if (!strcmp(arr[i].name, name)) break;
  return arr[i].val;
}

static void resolve_host(char *host, struct sockaddr *sa)
{
  struct addrinfo hints, *res = NULL;
  int ret;

  memset(&hints, 0, sizeof hints);
  hints.ai_family = AF_INET;
  hints.ai_socktype = SOCK_STREAM;
  if ((ret = getaddrinfo(host, NULL, &hints, &res))) 
    perror_exit("%s", gai_strerror(ret));

  memcpy(sa, res->ai_addr, res->ai_addrlen);
  freeaddrinfo(res);
}

static void check_flags(int *i, char** argv)
{
  struct sockaddr sa;
  int flag = *i, j;
  struct flags {
    char *name;
    int or, flag;
  } f[] = {
    {"pub",  1 ,ATF_PUBL},
    {"priv", 0 ,~ATF_PUBL},
    {"trail", 1, ATF_USETRAILERS},
    {"temp", 0, ~ATF_PERM},
    {"dontpub",1, ATF_DONTPUB},
  };
  
  for (;*argv; argv++) {
    for (j = 0;  j < ARRAY_LEN(f); j++) { 
      if (!strcmp(*argv, f[j].name)) {
        (f[j].or) ?(flag |= f[j].flag):(flag &= f[j].flag);
        break;
      }
    }
    if (j > 4 && !strcmp(*argv, "netmask")) {
      if (!*++argv) error_exit("NULL netmask");
      if (strcmp(*argv, "255.255.255.255")) {
        resolve_host(toys.optargs[0], &sa);
        memcpy(&req.arp_netmask, &sa, sizeof(sa));
        flag |= ATF_NETMASK;
      } else argv++; 
    } else if (j > 4 && !strcmp(*argv, "dev")) {
      if (!*++argv) error_exit("NULL dev");
      TT.device = *argv;
    } else if (j > 4) error_exit("invalid arg");
  }
  *i = flag;
}

static int set_entry(void) 
{
  int flags = 0;
  
  if (!toys.optargs[1]) error_exit("bad syntax");

  if (!(toys.optflags & FLAG_D)) {
    char *ptr = toys.optargs[1];
    char *p = ptr, *hw_addr = req.arp_ha.sa_data;

    while (*hw_addr && (p-ptr) < 6) {
      int val, len;

      if (*hw_addr == ':') hw_addr++;
      if (!sscanf(hw_addr, "%2x%n", &val, &len)) break;
      hw_addr += len;
      *p++ = val;
    }

    if ((p-ptr) != 6 || *hw_addr)
      error_exit("bad hw addr '%s'", req.arp_ha.sa_data);
  } else {
    struct ifreq ifre;

    xstrncpy(ifre.ifr_name, toys.optargs[1], IFNAMSIZ);
    xioctl(TT.sockfd, SIOCGIFHWADDR, &ifre);
    if ((toys.optflags & FLAG_H) && (ifre.ifr_hwaddr.sa_family != ARPHRD_ETHER)) 
      error_exit("protocol type mismatch");
    memcpy(&req.arp_ha, &(ifre.ifr_hwaddr), sizeof(req.arp_ha));
  }

  flags = ATF_PERM | ATF_COM;
  if (toys.optargs[2]) check_flags(&flags, (toys.optargs+2));
  req.arp_flags = flags;
  xstrncpy(req.arp_dev, TT.device, sizeof(req.arp_dev));
  xioctl(TT.sockfd, SIOCSARP, &req);
  
  if (toys.optflags & FLAG_v) xprintf("Entry set for %s\n", toys.optargs[0]);
  return 0;
}

static int ip_to_host(struct sockaddr *sa, int flag) 
{
  int status = 0;
  char hbuf[NI_MAXHOST] = {0,}, sbuf[NI_MAXSERV] = {0,}; 
  socklen_t len = sizeof(struct sockaddr_in6);
  
  *toybuf = 0;
  if (!(status = getnameinfo(sa, len, hbuf, sizeof(hbuf), sbuf, 
          sizeof(sbuf), flag))) {
    strcpy(toybuf, hbuf);
    return 0;
  }
  return 1;
}

static int delete_entry(void)
{
  int flags;
  
  flags = ATF_PERM;
  if (toys.optargs[1]) check_flags(&flags, (toys.optargs+1));
  req.arp_flags = flags;
  xstrncpy(req.arp_dev, TT.device, sizeof(req.arp_dev));
  xioctl(TT.sockfd, SIOCDARP, &req);
  
  if (toys.optflags & FLAG_v) xprintf("Delete entry for  %s\n", toys.optargs[0]);
  return 0;
}

void arp_main(void)
{
  struct sockaddr sa;
  char ip[128], hw_addr[128], mask[12], dev[128], *host_ip = NULL, *buf;
  int h_type, type, flag, i, fd, entries = 0, disp = 0;

  TT.device = "";
  memset(&sa, 0, sizeof(sa));
  memset(&req, 0, sizeof(req));
  TT.sockfd = xsocket(AF_INET, SOCK_STREAM, 0);

  if ((toys.optflags & FLAG_A) || (toys.optflags & FLAG_p)) {
    if ((type = get_index(aftype, 
            (TT.af_type_A)?TT.af_type_A:TT.af_type_p)) != AF_INET) 
      error_exit((type != -1)?"only inet supported by kernel":"unknown family");
  } 

  req.arp_ha.sa_family = ARPHRD_ETHER;
  if (toys.optflags & FLAG_H) {
    if ((type = get_index(hwtype, TT.hw_type)) != ARPHRD_ETHER) 
      error_exit((type != -1)?"h/w type not supported":"unknown h/w type");
    req.arp_ha.sa_family = type;
  }

  if (((toys.optflags & FLAG_s) || toys.optflags & FLAG_d)) { 
    if (!toys.optargs[0]) error_exit("host name req");
    resolve_host(toys.optargs[0], &sa);
    memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
  }

  if ((toys.optflags & FLAG_s) && !set_entry()) return;
  if ((toys.optflags & FLAG_d) && !delete_entry()) return; 

  //show arp chache
  fd = xopenro("/proc/net/arp");
  buf = get_line(fd);
  free(buf); //skip first line

  if (toys.optargs[0]) {
    resolve_host(toys.optargs[0], &sa);
    ip_to_host(&sa, NI_NUMERICHOST);
    host_ip = xstrdup(toybuf);
  }

  while ((buf = get_line(fd))) {
    char *host_name = "?";
    
    if ((sscanf(buf, "%s 0x%x 0x%x %s %s %s\n", ip,
        &h_type, &flag, hw_addr, mask, dev )) != 6) break;
    entries++;
    if (((toys.optflags & FLAG_H) && (get_index(hwtype, TT.hw_type) != h_type))
     || ((toys.optflags & FLAG_i) && strcmp(TT.interface, dev))
     || (toys.optargs[0] && strcmp(host_ip, ip))) {
      free(buf);
      continue;
    }

    resolve_host(buf, &sa);
    if (!(toys.optflags & FLAG_n)) { 
      if (!ip_to_host(&sa, NI_NAMEREQD)) host_name = toybuf;
    } else ip_to_host(&sa, NI_NUMERICHOST);
    
    disp++;
    printf("%s (%s) at" , host_name, ip);

    for (i = 0; hwtype[i].name; i++) 
      if (hwtype[i].val & h_type) break;
    if (!hwtype[i].name) error_exit("unknown h/w type");

    if (!(flag & ATF_COM)) {
      if ((flag & ATF_PUBL)) printf(" *");
      else printf(" <incomplete>");
    } else printf(" %s [%s]", hw_addr, hwtype[i].name);

    if (flag & ATF_NETMASK) printf("netmask %s ", mask);

    for (i = 0; flag_type[i].name; i++) 
      if (flag_type[i].val & flag) printf(" %s", flag_type[i].name);

    printf(" on %s\n", dev);
    free(buf);
  }
  
  if (toys.optflags & FLAG_v) 
    xprintf("Entries: %d\tSkipped: %d\tFound: %d\n",
        entries, entries - disp, disp);
  if (!disp) xprintf("No Match found in %d entries\n", entries);
  
  if (CFG_TOYBOX_FREE) {
    free(host_ip);
    free(buf);
    xclose(fd);
  }
}