X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=userv-utils.git;a=blobdiff_plain;f=ipif%2Fservice.c;h=eacfc63c1ce4d9782d7823716ec5b71281c55f13;hp=0a29f0695d4dfb21850c1ce943b2b7153c56a638;hb=f2add8c1b19c46ff78655278643c3c2851db7566;hpb=22fd0ebe07ae9f634cd5ab01dbc2e6506bc99b65 diff --git a/ipif/service.c b/ipif/service.c index 0a29f06..eacfc63 100644 --- a/ipif/service.c +++ b/ipif/service.c @@ -30,11 +30,11 @@ * * The remaining arguments are supplied by the (untrusted) caller: * - * ,,, + * ,,[,[][,[]]] * - * As for slattach. Supported protocols are slip, cslip, and - * adaptive. Alternatively, set to `debug' to print debugging info - * and exit. is address of the interface to be created + * As for slattach. The only supported protocol is slip. + * Alternatively, set to `debug' to print debugging info and + * exit. is address of the interface to be created * on the local system; is the address of the * point-to-point peer. They must be actual addresses (not * hostnames). @@ -48,9 +48,9 @@ * not supported). If no additional routes are to be set up, use `-' * or supply an empty argument. * - * Each item - whether a line file such as - * /etc/userv/ipif-networks, or supplied on the service program - * command line - is one of: + * Each item - whether a line in a file such as + * /etc/userv/ipif-networks, or the single trusted argument supplied + * on the service program command line - is one of: * * / * ./ @@ -82,6 +82,9 @@ * 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. @@ -91,12 +94,17 @@ * The service program should be run from userv with no-disconnect-hup. */ /* - * Copyright (C) 1999-2000,2003 Ian Jackson * This file is part of ipif, part of userv-utils * + * Copyright 1996-2013 Ian Jackson + * Copyright 1998 David Damerell + * Copyright 1999,2003 + * Chancellor Masters and Scholars of the University of Cambridge + * Copyright 2010 Tony Finch + * * 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 + * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but @@ -105,10 +113,7 @@ * 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. - * - * $Id$ + * along with userv-utils; if not, see http://www.gnu.org/licenses/. */ #include @@ -123,6 +128,7 @@ #include #include #include +#include #include #include @@ -143,13 +149,15 @@ #define ATXTLEN 16 static const unsigned long gidmaxval= (unsigned long)((gid_t)-2); -static const char *const protos_ok[]= { "slip", "cslip", "adaptive", 0 }; +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 int localallow, peerallow, allallow; +static int localallow, peerallow, ifnameallow, allallow; +static char *ifnamepat; static int nexroutes; static struct exroute { unsigned long prefix, mask; @@ -321,6 +329,34 @@ static void eat_prefixmask(const char **argp, const char *what, 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; @@ -445,6 +481,7 @@ static void pconfig(const char *configstr, int truncated) { case '*': permit_begin(); permit_range(0UL,0UL,1,0); + ifnameallow= 1; return; case '#': @@ -543,15 +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; - - if (!strcmp(carg,"debug")) { + + char *protostr= eat_optionalstr(&carg,"protocol","slip"); + if (!strcmp(protostr,"debug")) { proto= 0; } else { for (cprotop= protos_ok; - (proto= *cprotop) && strcmp(proto,carg); + (proto= *cprotop) && strcmp(proto,protostr); cprotop++); if (!proto) fatal("invalid protocol"); } + + ifnamepat= eat_optionalstr(&carg,"ifname pattern",default_ifnamepat); addrnet_mustdiffer("local-addr",localaddr,~0UL, "peer-addr",peeraddr,~0UL); @@ -597,6 +637,14 @@ static void checkpermit(void) { 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"); } @@ -635,7 +683,7 @@ static int task(const char *desc) { if (!pid) return 1; for (;;) { - pidr= waitpid(pid,&status,WNOHANG); + pidr= waitpid(pid,&status,0); if (pidr!=(pid_t)-1) break; if (errno==EINTR) continue; sysfatal("waitpid for task"); @@ -643,31 +691,29 @@ static int task(const char *desc) { assert(pidr==pid); if (WIFEXITED(status)) { - fprintf(stderr, - "userv-ipif service: %s unexpectedly exited with exit status %d\n", + if (WEXITSTATUS(status)) + fatal("userv-ipif service: %s exited with error exit status %d\n", desc, WEXITSTATUS(status)); } else if (WIFSIGNALED(status)) { - fprintf(stderr, - "userv-ipif service: %s unexpectedly killed by signal %s%s\n", - desc, strsignal(WTERMSIG(status)), - WCOREDUMP(status) ? " (core dumped)" : ""); + fatal("userv-ipif service: %s died due to signal %s%s\n", + desc, strsignal(WTERMSIG(status)), + WCOREDUMP(status) ? " (core dumped)" : ""); } else { - fprintf(stderr, "userv-ipif service: %s unexpectedly terminated" - " with unknown status code %d\n", desc, status); + fatal("userv-ipif service: %s unexpectedly terminated" + " with unknown status code %d\n", desc, status); } return 0; } 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; - assert(sizeof(ifr.ifr_name) >= sizeof(ifnamepat)); + assert(sizeof(ifr.ifr_name) >= strlen(ifnamepat)+1); strcpy(ifr.ifr_name, ifnamepat); tunfd= open("/dev/net/tun", O_RDWR); @@ -696,7 +742,7 @@ static void netconfigure(void) { sprintf(mtutxt,"%lu",mtu); execlp("ifconfig", "ifconfig", ifname, localtxt, - "netmask","255.255.255.255", "-broadcast", "pointopoint",peertxt, + "netmask","255.255.255.255", "pointopoint",peertxt, "-broadcast", "mtu",mtutxt, "up", (char*)0); sysfatal("cannot exec ifconfig"); } @@ -720,11 +766,13 @@ static void setnonblock(int fd) { } static void rx_packet(const uint8_t *packet, int len) { + if (!len) + return; for (;;) { int r= write(tunfd, packet, len); if (r<0) { if (errno==EINTR) continue; - if (errno==EAGAIN) return; /* oh well */ + if (errno==EAGAIN || errno==ENOMEM) return; /* oh well */ sysfatal("error writing packet to tun (transmitting)"); } assert(r==len); @@ -791,6 +839,9 @@ static void tx_packet(uint8_t *output_buf, const uint8_t *ip, int inlen) { else if (c==SLIP_ESC) { *op++= SLIP_ESC; *op++= SLIP_ESC_ESC; } else *op++= c; } + *op++= SLIP_END; + assert(op <= output_buf + mtu*2+2); + output_waiting= op - output_buf; } @@ -816,6 +867,10 @@ static void copydata(void) { * Output packets we buffer, so we poll only as appropriate for those. */ + /* Start by transmitting one END byte to say we're ready. */ + output_buf[0]= SLIP_END; + output_waiting= 1; + for (;;) { if (output_waiting) { r= write(1, output_buf, output_waiting); @@ -855,7 +910,7 @@ static void copydata(void) { r= read(0, input_buf + input_waiting, want); if (r>0) { input_waiting += r; - assert(r < sizeof(input_buf)); + assert(input_waiting <= sizeof(input_buf)); more_rx_data(input_buf, rx_packet_buf); } else if (r==0) { terminate(0);