Add nameif, a small tool for logical network interface naming.

1 files changed, 302 insertions, 0 deletions

diff --git a/nameif.c b/nameif.c
new file mode 100644
index 0000000..8d79b50
--- /dev/null
+++ b/nameif.c
@@ -0,0 +1,302 @@
+/* 
+ * Name Interfaces based on MAC address.
+ * Writen 2000 by Andi Kleen.
+ * Subject to the Gnu Public License, version 2.  
+ * TODO: make it support token ring etc.
+ * $Id: nameif.c,v 1.1 2000/10/18 17:26:29 ak Exp $
+ */ 
+#ifndef _GNU_SOURCE 
+#define _GNU_SOURCE
+#endif
+#include <stdio.h>
+#include <getopt.h>
+#include <sys/syslog.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdarg.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <linux/sockios.h>
+#include <errno.h>
+#include "intl.h" 
+
+const char default_conf[] = "/etc/mactab"; 
+const char *fname = default_conf; 
+int use_syslog; 
+int ctl_sk = -1; 
+
+void err(char *msg) 
+{ 
+	if (use_syslog) { 
+		syslog(LOG_ERR,"%s: %m", msg); 
+	} else { 
+		perror(msg); 
+	} 
+	exit(1); 
+}
+
+void complain(char *fmt, ...) 
+{ 
+	va_list ap;
+	va_start(ap,fmt);
+	if (use_syslog) { 
+		vsyslog(LOG_ERR,fmt,ap);
+	} else {
+		vfprintf(stderr,fmt,ap);
+		fputc('\n',stderr); 
+	}
+	va_end(ap); 
+	exit(1);
+} 
+
+void warning(char *fmt, ...) 
+{ 
+	va_list ap;
+	va_start(ap,fmt);
+	if (use_syslog) { 
+		vsyslog(LOG_ERR,fmt,ap);
+	} else {
+		vfprintf(stderr,fmt,ap);
+		fputc('\n',stderr); 
+	}
+	va_end(ap); 
+} 
+
+int parsemac(char *str, unsigned char *mac)
+{ 
+	char *s; 
+	while ((s = strsep(&str, ":")) != NULL) { 
+		unsigned byte;
+		if (sscanf(s,"%x", &byte)!=1 || byte > 0xff) 
+			return -1;
+		*mac++ = byte; 
+	}  
+	return 0;
+} 
+
+void *xmalloc(unsigned sz)
+{ 
+	void *p = calloc(sz,1);
+	if (!p) errno=ENOMEM, err("xmalloc"); 
+	return p; 
+} 
+
+void opensock(void)
+{
+	if (ctl_sk < 0) 
+		ctl_sk = socket(PF_INET,SOCK_DGRAM,0); 
+}
+
+#ifndef ifr_newname
+#define ifr_newname ifr_ifru.ifru_slave
+#endif
+
+int  setname(char *oldname, char *newname)
+{
+	struct ifreq ifr;
+	opensock(); 
+	memset(&ifr,0,sizeof(struct ifreq));
+	strcpy(ifr.ifr_name, oldname); 
+	strcpy(ifr.ifr_newname, newname); 
+	return ioctl(ctl_sk, SIOCSIFNAME, &ifr);
+}
+
+int getmac(char *name, unsigned char *mac)
+{
+	int r;
+	struct ifreq ifr;
+	opensock(); 
+	memset(&ifr,0,sizeof(struct ifreq));
+	strcpy(ifr.ifr_name, name); 
+	r = ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);
+	memcpy(mac, ifr.ifr_hwaddr.sa_data, 6); 
+	return r; 
+}
+
+struct change { 
+	struct change *next,**pprev;
+	char ifname[IFNAMSIZ+1];
+	unsigned char mac[6];
+}; 
+struct change *clist;
+
+struct change *lookupmac(unsigned char *mac) 
+{ 
+	struct change *ch;
+	for (ch = clist;ch;ch = ch->next) 
+		if (!memcmp(ch->mac, mac, 6))
+			return ch;
+	return NULL; 
+} 
+
+int addchange(char *p, struct change *ch, char *pos)
+{
+	if (strchr(ch->ifname, ':'))
+		warning(_("alias device %s at %s probably has no mac"), 
+			ch->ifname, pos); 
+	if (parsemac(p,ch->mac) < 0) 
+		complain(_("cannot parse MAC `%s' at %s"), p, pos); 
+	if (clist) 
+		clist->pprev = &ch->next;
+	ch->next = clist;
+	ch->pprev = &clist;
+	clist = ch;
+	return 0; 
+}
+
+void readconf(void)
+{
+	char *line; 
+	size_t linel; 
+	int linenum; 
+	FILE *ifh;
+	char *p;
+	int n;
+
+	ifh = fopen(fname, "r");
+	if (!ifh) 
+		complain(_("opening configuration file %s: %s"),fname,strerror(errno)); 
+
+	line = NULL; 
+	linel = 0;
+	linenum = 1; 
+	while (getdelim(&line, &linel, '\n', ifh) > 0) {
+		struct change *ch = xmalloc(sizeof(struct change)); 
+		char pos[20]; 
+
+		sprintf(pos, _("line %d"), linenum); 
+
+		if ((p = strchr(line,'#')) != NULL)
+			*p = '\0';
+		p = line; 
+		while (isspace(*p))
+			++p; 
+		if (*p == '\0')
+			continue; 
+		n = strcspn(p, " \t"); 
+		if (n > IFNAMSIZ) 
+			complain(_("interface name too long at line %d"), line);  
+		memcpy(ch->ifname, p, n); 
+		ch->ifname[n] = 0; 
+		p += n; 
+		p += strspn(p, " \t"); 
+		n = strspn(p, "0123456789ABCDEFabcdef:"); 
+		p[n] = 0; 
+		addchange(p, ch, pos);
+		linenum++;
+	}   
+	fclose(ifh); 
+}
+
+struct option lopt[] = { 
+	{"syslog", 0, NULL, 's' },
+	{"config-file", 1, NULL, 'c' },
+	{"help", 0, NULL, '?' }, 
+	{NULL}, 
+}; 
+
+void usage(void)
+{
+	fprintf(stderr, _("usage: nameif [-c configurationfile] [-s] {ifname macaddress}")); 
+	exit(1); 
+}
+
+int main(int ac, char **av) 
+{ 
+	FILE *ifh; 
+	char *p;
+	int n;
+	int linenum; 
+	char *line = NULL;
+	size_t linel = 0;
+
+	for (;;) {
+		int c = getopt_long(ac,av,"c:s",lopt,NULL);
+		if (c == -1) break;
+		switch (c) { 
+		default:
+		case '?':
+			usage(); 
+		case 'c':
+			fname = optarg;
+			break;
+		case 's':
+			use_syslog = 1;
+			break;
+		}
+	}
+
+	if (use_syslog) 
+		openlog("nameif",0,LOG_LOCAL0);
+		
+	while (optind < ac) { 
+		struct change *ch = xmalloc(sizeof(struct change)); 
+		char pos[30];
+
+		if ((ac-optind) & 1) 
+			usage();
+		if (strlen(av[optind])+1>IFNAMSIZ) 
+			complain(_("interface name `%s' too long"), av[optind]);
+		strcpy(ch->ifname, av[optind]); 
+		optind++; 
+		sprintf(pos,_("argument %d"),optind); 
+		addchange(av[optind], ch, pos); 
+		optind++; 
+	} 
+
+	if (!clist || fname != default_conf) 
+		readconf(); 
+
+	ifh = fopen("/proc/net/dev", "r"); 
+	if (!ifh)  complain(_("open of /proc/net/dev: %s"), strerror(errno)); 
+
+
+	linenum = 0;
+	while (getdelim(&line, &linel, '\n', ifh) > 0) {
+		struct change *ch; 
+		unsigned char mac[6];
+
+		if (linenum++ < 2) 
+			continue;
+			
+		p = line; 
+		while (isspace(*p)) 
+			++p;
+		n = strcspn(p, ": \t");  
+		p[n] = 0; 
+		
+		if (n > IFNAMSIZ-1) 
+			complain(_("interface name `%s' too long"), p); 
+			
+		if (getmac(p, mac) < 0) 
+			continue;
+			
+		ch = lookupmac(mac); 
+		if (!ch) 
+			continue;
+			
+		*ch->pprev = ch->next;
+		if (strcmp(p, ch->ifname)) { 
+			if (setname(p, ch->ifname) < 0)  
+				complain(_("cannot change name of %s to %s: %s"),
+						p, ch->ifname, strerror(errno)); 
+		} 
+		free(ch);
+	} 
+	fclose(ifh); 
+	
+	while (clist) { 
+		struct change *ch = clist;
+		clist = clist->next;
+		warning(_("interface '%s' not found"), ch->ifname); 
+		free(ch); 
+	}
+
+	if (use_syslog)
+		closelog();
+	return 0;
+} 
+