fix #>&- syntax for closing fds
[oweals/busybox.git] / networking / nameif.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * nameif.c - Naming Interfaces based on MAC address for busybox.
4  *
5  * Written 2000 by Andi Kleen.
6  * Busybox port 2002 by Nick Fedchik <nick@fedchik.org.ua>
7  *                      Glenn McGrath
8  * Extended matching support 2008 by Nico Erfurth <masta@perlgolf.de>
9  *
10  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
11  */
12
13 #include "libbb.h"
14 #include <syslog.h>
15 #include <net/if.h>
16 #include <netinet/ether.h>
17 #include <linux/sockios.h>
18
19 #ifndef IFNAMSIZ
20 #define IFNAMSIZ 16
21 #endif
22
23 /* Taken from linux/sockios.h */
24 #define SIOCSIFNAME     0x8923  /* set interface name */
25
26 /* Octets in one Ethernet addr, from <linux/if_ether.h> */
27 #define ETH_ALEN        6
28
29 #ifndef ifr_newname
30 #define ifr_newname ifr_ifru.ifru_slave
31 #endif
32
33 typedef struct ethtable_s {
34         struct ethtable_s *next;
35         struct ethtable_s *prev;
36         char *ifname;
37         struct ether_addr *mac;
38 #if ENABLE_FEATURE_NAMEIF_EXTENDED
39         char *bus_info;
40         char *driver;
41 #endif
42 } ethtable_t;
43
44 #if ENABLE_FEATURE_NAMEIF_EXTENDED
45 /* Cut'n'paste from ethtool.h */
46 #define ETHTOOL_BUSINFO_LEN 32
47 /* these strings are set to whatever the driver author decides... */
48 struct ethtool_drvinfo {
49         uint32_t cmd;
50         char  driver[32]; /* driver short name, "tulip", "eepro100" */
51         char  version[32];  /* driver version string */
52         char  fw_version[32]; /* firmware version string, if applicable */
53         char  bus_info[ETHTOOL_BUSINFO_LEN];  /* Bus info for this IF. */
54         /* For PCI devices, use pci_dev->slot_name. */
55         char  reserved1[32];
56         char  reserved2[16];
57         uint32_t n_stats;  /* number of u64's from ETHTOOL_GSTATS */
58         uint32_t testinfo_len;
59         uint32_t eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
60         uint32_t regdump_len;  /* Size of data from ETHTOOL_GREGS (bytes) */
61 };
62 #define ETHTOOL_GDRVINFO  0x00000003 /* Get driver info. */
63 #endif
64
65
66 static void nameif_parse_selector(ethtable_t *ch, char *selector)
67 {
68         struct ether_addr *lmac;
69 #if ENABLE_FEATURE_NAMEIF_EXTENDED
70         int found_selector = 0;
71
72         while (*selector) {
73                 char *next;
74 #endif
75                 selector = skip_whitespace(selector);
76 #if ENABLE_FEATURE_NAMEIF_EXTENDED
77                 if (*selector == '\0')
78                         break;
79                 /* Search for the end .... */
80                 next = skip_non_whitespace(selector);
81                 if (*next)
82                         *next++ = '\0';
83                 /* Check for selectors, mac= is assumed */
84                 if (strncmp(selector, "bus=", 4) == 0) {
85                         ch->bus_info = xstrdup(selector + 4);
86                         found_selector++;
87                 } else if (strncmp(selector, "driver=", 7) == 0) {
88                         ch->driver = xstrdup(selector + 7);
89                         found_selector++;
90                 } else {
91 #endif
92                         lmac = xmalloc(ETH_ALEN);
93                         ch->mac = ether_aton_r(selector + (strncmp(selector, "mac=", 4) ? 0 : 4), lmac);
94                         if (ch->mac == NULL)
95                                 bb_error_msg_and_die("cannot parse %s", selector);
96 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
97                         found_selector++;
98                 };
99                 selector = next;
100         }
101         if (found_selector == 0)
102                 bb_error_msg_and_die("no selectors found for %s", ch->ifname);
103 #endif
104 }
105
106 static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
107 {
108         ethtable_t *ch;
109         if (strlen(ifname) >= IFNAMSIZ)
110                 bb_error_msg_and_die("interface name '%s' too long", ifname);
111         ch = xzalloc(sizeof(*ch));
112         ch->ifname = xstrdup(ifname);
113         nameif_parse_selector(ch, selector);
114         ch->next = *clist;
115         if (*clist)
116                 (*clist)->prev = ch;
117         *clist = ch;
118 }
119
120 #if ENABLE_FEATURE_CLEAN_UP
121 static void delete_eth_table(ethtable_t *ch)
122 {
123         free(ch->ifname);
124 #if ENABLE_FEATURE_NAMEIF_EXTENDED
125         free(ch->bus_info);
126         free(ch->driver);
127 #endif
128         free(ch->mac);
129         free(ch);
130 };
131 #else
132 void delete_eth_table(ethtable_t *ch);
133 #endif
134
135 int nameif_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
136 int nameif_main(int argc, char **argv)
137 {
138         ethtable_t *clist = NULL;
139         const char *fname = "/etc/mactab";
140         int ctl_sk;
141         ethtable_t *ch;
142         parser_t *parser;
143         char *token[2];
144
145         if (1 & getopt32(argv, "sc:", &fname)) {
146                 openlog(applet_name, 0, LOG_LOCAL0);
147                 /* Why not just "="? I assume logging to stderr
148                  * can't hurt. 2>/dev/null if you don't like it: */
149                 logmode |= LOGMODE_SYSLOG;
150         }
151         argc -= optind;
152         argv += optind;
153
154         if (argc & 1)
155                 bb_show_usage();
156
157         if (argc) {
158                 while (*argv) {
159                         char *ifname = xstrdup(*argv++);
160                         prepend_new_eth_table(&clist, ifname, *argv++);
161                 }
162         } else {
163                 parser = config_open(fname);
164                 while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL))
165                         prepend_new_eth_table(&clist, token[0], token[1]);
166                 config_close(parser);
167         }
168
169         ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
170         parser = config_open2("/proc/net/dev", xfopen_for_read);
171
172         while (clist && config_read(parser, token, 2, 2, "\0: \t", PARSE_NORMAL)) {
173                 struct ifreq ifr;
174 #if  ENABLE_FEATURE_NAMEIF_EXTENDED
175                 struct ethtool_drvinfo drvinfo;
176 #endif
177                 if (parser->lineno < 2)
178                         continue; /* Skip the first two lines */
179
180                 /* Find the current interface name and copy it to ifr.ifr_name */
181                 memset(&ifr, 0, sizeof(struct ifreq));
182                 strncpy_IFNAMSIZ(ifr.ifr_name, token[0]);
183
184 #if ENABLE_FEATURE_NAMEIF_EXTENDED
185                 /* Check for driver etc. */
186                 memset(&drvinfo, 0, sizeof(struct ethtool_drvinfo));
187                 drvinfo.cmd = ETHTOOL_GDRVINFO;
188                 ifr.ifr_data = (caddr_t) &drvinfo;
189                 /* Get driver and businfo first, so we have it in drvinfo */
190                 ioctl(ctl_sk, SIOCETHTOOL, &ifr);
191 #endif
192                 ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
193
194                 /* Search the list for a matching device */
195                 for (ch = clist; ch; ch = ch->next) {
196 #if ENABLE_FEATURE_NAMEIF_EXTENDED
197                         if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
198                                 continue;
199                         if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
200                                 continue;
201 #endif
202                         if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
203                                 continue;
204                         /* if we came here, all selectors have matched */
205                         break;
206                 }
207                 /* Nothing found for current interface */
208                 if (!ch)
209                         continue;
210
211                 if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
212                         strcpy(ifr.ifr_newname, ch->ifname);
213                         ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
214                                         "cannot change ifname %s to %s",
215                                         ifr.ifr_name, ch->ifname);
216                 }
217                 /* Remove list entry of renamed interface */
218                 if (ch->prev != NULL)
219                         ch->prev->next = ch->next;
220                 else
221                         clist = ch->next;
222                 if (ch->next != NULL)
223                         ch->next->prev = ch->prev;
224                 if (ENABLE_FEATURE_CLEAN_UP)
225                         delete_eth_table(ch);
226         }
227         if (ENABLE_FEATURE_CLEAN_UP) {
228                 for (ch = clist; ch; ch = ch->next)
229                         delete_eth_table(ch);
230                 config_close(parser);
231         };
232
233         return 0;
234 }