/*
- * userv service (or standalone program)
- * for per-user IP subranges.
+ * userv service (or standalone program) for per-user IP subranges.
+ *
+ * When invoked appropriately, it creates a point-to-point network
+ * interface with specified parameters. It arranges for packets sent out
+ * via that interface by the kernel to appear on its own stdout in SLIP or
+ * CSLIP encoding, and packets injected into its own stdin to be given to
+ * the kernel as if received on that interface. Optionally, additional
+ * routes can be set up to arrange for traffic for other address ranges to
+ * be routed through the new interface.
+ *
+ * This is the service program, which is invoked as root from userv (or may
+ * be invoked firectly).
+ *
+ * Its arguments are supposed to be, in order, as follows:
+ *
+ * The first two arguments are usually supplied by the userv
+ * configuration. See the file `ipif/ipif' in the source tree, which
+ * is installed in /etc/userv/services.d/ipif by `make install':
*
- * This is invoked as root, directly from userv.
- * Its arguments are supposed to be, in order:
* <config>
- * Specifies address ranges and gids which own them.
- * -- Indicates that the remaining arguments are user-supplied
- * and therefore untrusted.
+ *
+ * Specifies address ranges and gids which own them. The default
+ * configuration supplies /etc/userv/ipif-networks, which is then read
+ * for a list of entries, one per line.
+ *
+ * --
+ * Serves to separate the user-supplied and therefore untrusted
+ * arguments from the trusted first argument.
+ *
+ * The remaining arguments are supplied by the (untrusted) caller:
+ *
* <local-addr>,<peer-addr>,<mtu>,<proto>
+ *
* As for slattach. Supported protocols are slip, cslip, and
- * adaptive. Alternatively, set to `debug' to print debugging
- * info. <local-addr> is address of the interface on chiark;
- * <peer-addr> is the address of the point-to-point peer.
+ * adaptive. Alternatively, set to `debug' to print debugging info
+ * and exit. <local-addr> is address of the interface to be created
+ * on the local system; <peer-addr> is the address of the
+ * point-to-point peer. They must be actual addresses (not
+ * hostnames).
+ *
* <prefix>/<mask>,<prefix>/<mask>,...
- * List of additional routes to add for this interface.
- * May be the empty argument, or `-' if this is problematic.
*
- * <config> is either
- * <gid>,<prefix>/<len>[,<junk>]
- * indicating that that gid may allocate addresses in
- * the relevant subspace (<junk> is ignored)
- * or #...
- * which is a comment
- * or /<config-file-name> or ./<config-file-name> or ../<config-file-name>
- * which refers to a file which contains lines which
- * are each <config>
- * or *
- * which means that anything is permitted
- *
- * Should be run from userv with no-disconnect-hup.
+ * List of additional routes to add for this interface. routes will
+ * be set up on the local system arranging for packets for those
+ * networks to be sent via the created interface. <prefix> must be an
+ * IPv4 address, and mask must be an integer (dotted-quad masks are
+ * not supported). If no additional routes are to be set up, use `-'
+ * or supply an empty argument.
+ *
+ * Each <config> item - whether a line file such as
+ * /etc/userv/ipif-networks, or supplied on the service program
+ * command line - is one of:
+ *
+ * /<config-file-name>
+ * ./<config-file-name>
+ * ../<config-file-name>
+ *
+ * Reads a file which contains lines which are each <config>
+ * items.
+ *
+ * <gid>,[=]<prefix>/<len>[,<junk>]
+ *
+ * Indicates that <gid> may allocate addresses in the relevant address
+ * range (<junk> is ignored). <gid> must be numeric. To specify a
+ * single host address, you must specify a mask of /32. If `=' is
+ * specified then the specific subrange is only allowed for the local
+ * endpoint address, but not for remote addresses.
+ *
+ * *
+ * Means that anything is to be permitted. This should not appear in
+ * /etc/userv/ipif-networks, as that would permit any user on the
+ * system to create any interfaces with any addresses and routes
+ * attached. It is provided so that root can usefully invoke the ipif
+ * service program directly (not via userv), without needing to set up
+ * permissions in /etc/userv/ipif-networks.
+ *
+ * #...
+ *
+ * Comment. Blank lines are also ignored.
+ *
+ * NB: Permission is granted if _any_ config entry matches the request.
+ *
+ * The service program should be run from userv with no-disconnect-hup.
+ */
+/*
+ * Copyright (C) 1999-2000 Ian Jackson
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with userv-utils; if not, write to the Free Software
+ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * $Id$
*/
#include <stdio.h>
#define NARGS 4
#define MAXEXROUTES 5
-#define ATXTLEN 12
+#define ATXTLEN 16
static const unsigned long gidmaxval= (unsigned long)((gid_t)-2);
static const char *const protos_ok[]= { "slip", "cslip", "adaptive", 0 };
sprintf(whatbuf,"%s length",what);
len= eat_number(argp,whatbuf, 0,32, endchars,endchar_r);
- mask= (~0UL << (32-len));
+ mask= len ? (~0UL << (32-len)) : 0UL;
if (prefix & ~mask) badusage("%s prefix %08lx not fully contained in mask %08lx",
what,prefix,mask);
*prefix_r= prefix;
}
-static void permit(unsigned long pprefix, unsigned long pmask) {
+static void permit(unsigned long pprefix, unsigned long pmask, int localonly) {
int i, any;
assert(!(pprefix & ~pmask));
+ any= 0;
- if (!proto) fputs("permits",stdout);
+ if (!proto) fputs(localonly ? "permits-l" : "permits",stdout);
if (addrnet_isin(localaddr,~0UL, pprefix,pmask)) {
if (!proto) fputs(" local-addr",stdout);
any= localallow= 1;
}
- if (addrnet_isin(peeraddr,~0UL, pprefix,pmask)) {
- if (!proto) fputs(" peer-addr",stdout);
- any= peerallow= 1;
- }
- for (i=0; i<nexroutes; i++) {
- if (addrnet_isin(exroutes[i].prefix,exroutes[i].mask, pprefix,pmask)) {
- if (!proto) printf(" route#%d",i);
- any= exroutes[i].allow= 1;
+ if (!localonly) {
+ if (addrnet_isin(peeraddr,~0UL, pprefix,pmask)) {
+ if (!proto) fputs(" peer-addr",stdout);
+ any= peerallow= 1;
+ }
+ for (i=0; i<nexroutes; i++) {
+ if (addrnet_isin(exroutes[i].prefix,exroutes[i].mask, pprefix,pmask)) {
+ if (!proto) printf(" route#%d",i);
+ any= exroutes[i].allow= 1;
+ }
}
}
if (!proto) {
- if (!any) fputs(" nothing!",stderr);
+ if (!any) fputs(" nothing",stdout);
putchar('\n');
}
}
static void pconfig(const char *configstr, int truncated) {
unsigned long fgid, tgid, pprefix, pmask;
- int plen;
+ int plen, localonly;
char ptxt[ATXTLEN];
const char *gidlist;
switch (configstr[0]) {
case '*':
if (strcmp(configstr,"*")) badusage("`*' directive must be only thing on line");
- permit(0UL,0UL);
+ permit(0UL,0UL,0);
return;
case '#':
badusage("unknown configuration directive");
fgid= eat_number(&configstr,"gid", 0,gidmaxval, ",",0);
+ if (configstr[0] == '=') {
+ localonly= 1;
+ configstr++;
+ } else {
+ localonly= 0;
+ }
eat_prefixmask(&configstr,"permitted-prefix", ",",0, &pprefix,&pmask,&plen);
if (!configstr && truncated) badusage("gid,prefix/len,... spec too long");
tgid= eat_number(&gidlist,"userv-gid", 0,gidmaxval, " ",0);
if (tgid == fgid) break;
}
- permit(pprefix,pmask);
+ permit(pprefix,pmask,localonly);
return;
}
}
}
setsigmask(&fullset);
l= strlen(ifnbuf);
- if (l<0 || ifnbuf[l-1] != '\n') fatal("slattach gave strange output `%s'",ifnbuf);
+ if (l<=0 || ifnbuf[l-1] != '\n') fatal("slattach gave strange output `%s'",ifnbuf);
ifnbuf[l-1]= 0;
for (k=l; k>0 && ifnbuf[k-1]!=' '; k--);
ifname= ifnbuf+k;
~ian / userv-utils.git / blobdiff