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ipif: Permit specifying interface name, if * is allowed
[userv-utils.git]
/
ipif
/
service.c
diff --git
a/ipif/service.c
b/ipif/service.c
index df039269cf19297b2f09dceba9a0866ca88e39d4..eacfc63c1ce4d9782d7823716ec5b71281c55f13 100644
(file)
--- a/
ipif/service.c
+++ b/
ipif/service.c
@@
-30,7
+30,7
@@
*
* The remaining arguments are supplied by the (untrusted) caller:
*
*
* The remaining arguments are supplied by the (untrusted) caller:
*
- * <local-addr>,<peer-addr>,<mtu>
,<proto>
+ * <local-addr>,<peer-addr>,<mtu>
[,[<proto>][,[<ifnamepat>]]]
*
* As for slattach. The only supported protocol is slip.
* Alternatively, set to `debug' to print debugging info and
*
* As for slattach. The only supported protocol is slip.
* Alternatively, set to `debug' to print debugging info and
@@
-82,6
+82,9
@@
* service program directly (not via userv), without needing to set up
* permissions in /etc/userv/ipif-networks.
*
* service program directly (not via userv), without needing to set up
* permissions in /etc/userv/ipif-networks.
*
+ * Only `*' permits interface name patterns other than the default
+ * value of `userv%d'.
+ *
* #...
*
* Comment. Blank lines are also ignored.
* #...
*
* Comment. Blank lines are also ignored.
@@
-125,6
+128,7
@@
#include <unistd.h>
#include <stdint.h>
#include <poll.h>
#include <unistd.h>
#include <stdint.h>
#include <poll.h>
+#include <stddef.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/wait.h>
@@
-147,11
+151,13
@@
static const unsigned long gidmaxval= (unsigned long)((gid_t)-2);
static const char *const protos_ok[]= { "slip", 0 };
static const int signals[]= { SIGHUP, SIGINT, SIGTERM, 0 };
static const unsigned long gidmaxval= (unsigned long)((gid_t)-2);
static const char *const protos_ok[]= { "slip", 0 };
static const int signals[]= { SIGHUP, SIGINT, SIGTERM, 0 };
+static const char default_ifnamepat[]= "userv%d";
static const char *configstr, *proto;
static unsigned long localaddr, peeraddr, mtu;
static int localpming, peerpming;
static const char *configstr, *proto;
static unsigned long localaddr, peeraddr, mtu;
static int localpming, peerpming;
-static int localallow, peerallow, allallow;
+static int localallow, peerallow, ifnameallow, allallow;
+static char *ifnamepat;
static int nexroutes;
static struct exroute {
unsigned long prefix, mask;
static int nexroutes;
static struct exroute {
unsigned long prefix, mask;
@@
-323,6
+329,34
@@
static void eat_prefixmask(const char **argp, const char *what,
if (len_r) *len_r= len;
}
if (len_r) *len_r= len;
}
+static char *eat_optionalstr(const char **argp,
+ const char *what,
+ const char *def) {
+ ptrdiff_t len;
+ const char *start= *argp;
+ if (!start) {
+ len = 0;
+ } else {
+ const char *comma= strchr(start, ',');
+ if (comma) {
+ len= comma - start;
+ *argp= comma + 1;
+ } else {
+ len= strlen(start);
+ *argp= 0;
+ }
+ }
+ if (!len) {
+ start= def;
+ len= strlen(def);
+ }
+ char *r = malloc(len+1);
+ if (!r) sysfatal("malloc for command line string");
+ memcpy(r,start,len);
+ r[len]= 0;
+ return r;
+}
+
static int addrnet_isin(unsigned long prefix, unsigned long mask,
unsigned long mprefix, unsigned long mmask) {
return !(~mask & mmask) && (prefix & mmask) == mprefix;
static int addrnet_isin(unsigned long prefix, unsigned long mask,
unsigned long mprefix, unsigned long mmask) {
return !(~mask & mmask) && (prefix & mmask) == mprefix;
@@
-447,6
+481,7
@@
static void pconfig(const char *configstr, int truncated) {
case '*':
permit_begin();
permit_range(0UL,0UL,1,0);
case '*':
permit_begin();
permit_range(0UL,0UL,1,0);
+ ifnameallow= 1;
return;
case '#':
return;
case '#':
@@
-545,15
+580,18
@@
static void parseargs(int argc, const char *const *argv) {
peeraddr= eat_addr(&carg,"peer-addr", ",",0);
mtu= eat_number(&carg,"mtu", 576,65536, ",",0);
localallow= peerallow= 0;
peeraddr= eat_addr(&carg,"peer-addr", ",",0);
mtu= eat_number(&carg,"mtu", 576,65536, ",",0);
localallow= peerallow= 0;
-
- if (!strcmp(carg,"debug")) {
+
+ char *protostr= eat_optionalstr(&carg,"protocol","slip");
+ if (!strcmp(protostr,"debug")) {
proto= 0;
} else {
for (cprotop= protos_ok;
proto= 0;
} else {
for (cprotop= protos_ok;
- (proto= *cprotop) && strcmp(proto,
carg
);
+ (proto= *cprotop) && strcmp(proto,
protostr
);
cprotop++);
if (!proto) fatal("invalid protocol");
}
cprotop++);
if (!proto) fatal("invalid protocol");
}
+
+ ifnamepat= eat_optionalstr(&carg,"ifname pattern",default_ifnamepat);
addrnet_mustdiffer("local-addr",localaddr,~0UL, "peer-addr",peeraddr,~0UL);
addrnet_mustdiffer("local-addr",localaddr,~0UL, "peer-addr",peeraddr,~0UL);
@@
-599,6
+637,14
@@
static void checkpermit(void) {
sprintf(erwhatbuf, "route#%d", i);
checkallow(exroutes[i].allow, erwhatbuf, exroutes[i].prefixtxt, exroutes[i].masktxt);
}
sprintf(erwhatbuf, "route#%d", i);
checkallow(exroutes[i].allow, erwhatbuf, exroutes[i].prefixtxt, exroutes[i].masktxt);
}
+ if (!strcmp(ifnamepat,default_ifnamepat))
+ ifnameallow= 1;
+ if (!ifnameallow) {
+ fprintf(stderr,
+ "userv-ipif service: access denied for interface name %s\n",
+ ifnamepat);
+ allallow= 0;
+ }
if (!allallow) fatal("access denied");
}
if (!allallow) fatal("access denied");
}
@@
-661,14
+707,13
@@
static int task(const char *desc) {
}
static void createif(void) {
}
static void createif(void) {
- static const char ifnamepat[]= "userv%d";
struct ifreq ifr;
int r;
memset(&ifr,0,sizeof(ifr));
ifr.ifr_flags= IFF_TUN | IFF_NO_PI;
struct ifreq ifr;
int r;
memset(&ifr,0,sizeof(ifr));
ifr.ifr_flags= IFF_TUN | IFF_NO_PI;
- assert(sizeof(ifr.ifr_name) >= s
izeof(ifnamepat)
);
+ assert(sizeof(ifr.ifr_name) >= s
trlen(ifnamepat)+1
);
strcpy(ifr.ifr_name, ifnamepat);
tunfd= open("/dev/net/tun", O_RDWR);
strcpy(ifr.ifr_name, ifnamepat);
tunfd= open("/dev/net/tun", O_RDWR);