From 1e9634732a90ffe9bf3aeff4be92b5baa402599f Mon Sep 17 00:00:00 2001 From: ian Date: Sun, 19 Sep 1999 14:21:25 +0000 Subject: [PATCH] Argument parsing and configureation done and seems to work. --- ipif/service.c | 419 +++++++++++++++++++++++++++++++++---------------- ipif/x.gdb | 2 +- 2 files changed, 288 insertions(+), 133 deletions(-) diff --git a/ipif/service.c b/ipif/service.c index c1c1f71..b770623 100644 --- a/ipif/service.c +++ b/ipif/service.c @@ -4,17 +4,8 @@ * * This is invoked as root, directly from userv. * Its arguments are supposed to be, in order: - * / - * Specifies the base address and prefix to restrict the - * addresses used to. - * -:/[,...] - * The ranges specified by are checked until - * one is found which matches at least one gid in USERV_GID. - * Then the gid will have added to it and will then be - * masked so that it is long (higher set bits are - * discarded). The result is added to the base prefix. It is an - * error for no gid to match. Alternatively, if this argument - * is `*' then USERV_GID is not checked. + * + * Specifies address ranges and gids which own them. * -- Indicates that the remaining arguments are user-supplied * and therefore untrusted. * ,,, @@ -26,6 +17,18 @@ * List of additional routes to add for this interface. * May be the empty argument. * + * is either + * ,/[,] + * indicating that that gid may allocate addresses in + * the relevant subspace ( is ignored) + * or #... + * which is a comment + * or / or ./ or ../ + * which refers to a file which contains lines which + * are each + * or * + * which means that anything is permitted + * * Should be run from userv with no-disconnect-hup. */ @@ -34,36 +37,88 @@ #include #include #include +#include +#include +#include -#define NARGS 5 +#define NARGS 4 #define MAXEXROUTES 5 #define ATXTLEN 12 -static const char *proto; -static unsigned long baseprefix, basemask; +static const unsigned long gidmaxval= (unsigned long)((gid_t)-2); +static const char *const protos_ok[]= { "slip", "cslip", "adaptive", 0 }; + +static const char *configstr, *proto; static unsigned long localaddr, peeraddr, mtu; +static int localallow, peerallow, allallow; static int nexroutes; static struct exroute { unsigned long prefix, mask; + int allow; char prefixtxt[ATXTLEN], masktxt[ATXTLEN]; } exroutes[MAXEXROUTES]; -char localtxt[ATXTLEN]; -char peertxt[ATXTLEN]; +static char localtxt[ATXTLEN]; +static char peertxt[ATXTLEN]; + +static struct pplace { + struct pplace *parent; + const char *filename; + int lineno; +} *cpplace; + +static void fatal(const char *fmt, ...) + __attribute__((format(printf,1,2))); +static void fatal(const char *fmt, ...) { + va_list al; + va_start(al,fmt); -static void fatal(const char *msg) { - fprintf(stderr,"userv-ipif: service: fatal error: %s\n",msg); + fputs("userv-ipif service: fatal error: ",stderr); + vfprintf(stderr, fmt, al); + putc('\n',stderr); exit(8); } -static void sysfatal(const char *msg) { - fprintf(stderr,"userv-ipif: service: fatal system error: %s: %s\n", - msg, strerror(errno)); +static void sysfatal(const char *fmt, ...) + __attribute__((format(printf,1,2))); +static void sysfatal(const char *fmt, ...) { + va_list al; + int e; + + e= errno; + va_start(al,fmt); + + fputs("userv-ipif service: fatal system error",stderr); + vfprintf(stderr, fmt, al); + fprintf(stderr,"%s\n", strerror(e)); exit(12); } + + +static void badusage(const char *fmt, ...) + __attribute__((format(printf,1,2))); +static void badusage(const char *fmt, ...) { + va_list al; + struct pplace *cpp; -static void badusage(void) { - fputs("userv-ipif: service: bad usage or permission denied\n",stderr); + if (cpplace) { + fprintf(stderr, + "userv-ipif service: %s:%d: ", + cpplace->filename, cpplace->lineno); + } else { + fputs("userv-ipif service: invalid usage: ",stderr); + } + va_start(al,fmt); + vfprintf(stderr, fmt, al); + putc('\n',stderr); + + if (cpplace) { + for (cpp=cpplace->parent; cpp; cpp=cpp->parent) { + fprintf(stderr, + "userv-ipif service: %s:%d: ... in file included from here\n", + cpp->filename, cpp->lineno); + } + } exit(16); } @@ -88,57 +143,39 @@ static unsigned long eat_number(const char **argp, const char *what, char *ep; int endchar; - if (!*argp) { fprintf(stderr,"missing number %s\n",what); badusage(); } + if (!*argp) { badusage("missing number %s\n",what); } rv= strtoul(*argp,&ep,0); if ((endchar= *ep)) { - if (!endchars) { fprintf(stderr,"junk after number %s\n",what); badusage(); } - if (!strchr(endchars,endchar)) { - fprintf(stderr,"invalid delimiter %c after number %s: expected %s (or none?)\n", - endchar,what,endchars); - badusage(); - } + if (!endchars) badusage("junk after number %s\n",what); + if (!strchr(endchars,endchar)) + badusage("invalid character or delimiter `%c' in or after number, %s:" + " expected %s (or none?)\n", endchar,what,endchars); *argp= ep+1; } else { *argp= 0; } if (endchar_r) *endchar_r= endchar; - if (rv < min || rv > max) { - fprintf(stderr,"number %s value %lu out of range %lu..%lu", - what, rv, min, max); - badusage(); - } + if (rv < min || rv > max) badusage("number %s value %lu out of range %lu..%lu", + what, rv, min, max); return rv; } -static void addrnet_mustbein(const char *what, - unsigned long prefix, unsigned long mask, - unsigned long mprefix, unsigned long mmask) { - if (!(~mask & mmask) && (prefix & mmask) == mprefix) return; - fprintf(stderr, "%s %08lx/%08lx not in required subspace %08lx/%08lx\n", - what, prefix, mask, mprefix, mmask); - badusage(); -} - static void addrnet_mustdiffer(const char *w1, unsigned long p1, unsigned long m1, const char *w2, unsigned long p2, unsigned long m2) { unsigned long mask; mask= m1&m2; if ((p1 & mask) != (p2 & mask)) return; - fprintf(stderr, "%s %08lx/%08lx overlaps/clashes with %s %08lx/%08lx", - w1,p1,m1, w2,p2,m2); - badusage(); + badusage("%s %08lx/%08lx overlaps/clashes with %s %08lx/%08lx", + w1,p1,m1, w2,p2,m2); } static unsigned long eat_addr(const char **argp, const char *what, - unsigned long mprefix, unsigned long mmask, const char *endchars, int *endchar_r) { char whatbuf[100]; unsigned long rv; int i; - assert(!(~mmask & mprefix)); - for (rv=0, i=0; i<4; i++) { @@ -147,12 +184,10 @@ static unsigned long eat_addr(const char **argp, const char *what, rv |= eat_number(argp,whatbuf, 0,255, i<3 ? "." : endchars, endchar_r); } - addrnet_mustbein(what,rv,~0UL, mprefix,mmask); return rv; } static void eat_prefixmask(const char **argp, const char *what, - unsigned long mprefix, unsigned long mmask, const char *endchars, int *endchar_r, unsigned long *prefix_r, unsigned long *mask_r, int *len_r) { /* mask_r and len_r may be 0 */ @@ -160,71 +195,170 @@ static void eat_prefixmask(const char **argp, const char *what, int len; unsigned long prefix, mask; - prefix= eat_addr(argp,what, 0,0, "/",0); + prefix= eat_addr(argp,what, "/",0); sprintf(whatbuf,"%s length",what); len= eat_number(argp,whatbuf, 0,32, endchars,endchar_r); mask= (~0UL << (32-len)); - if (prefix & ~mask) { - fprintf(stderr,"%s prefix %08lx not fully contained in mask %08lx\n", - what,prefix,mask); - badusage(); - } - addrnet_mustbein(what,prefix,mask, mprefix,mmask); + if (prefix & ~mask) badusage("%s prefix %08lx not fully contained in mask %08lx\n", + what,prefix,mask); *prefix_r= prefix; if (mask_r) *mask_r= mask; if (len_r) *len_r= len; } + +static int addrnet_isin(unsigned long prefix, unsigned long mask, + unsigned long mprefix, unsigned long mmask) { + return !(~mask & mmask) && (prefix & mmask) == mprefix; +} -int main(int argc, const char *const *argv) { - static unsigned long gidmaxval= (unsigned long)((gid_t)-2); - static const char *const protos_ok[]= { "slip", "cslip", "adaptive", 0 }; - unsigned long gidmin, gidmax, gidadd; - int baselen; - unsigned long routeaddr, routemask, tgid; - const char *carg, *gidlist; - const char *const *cprotop; - int gidlen, i; - char erwhatbuf[100], erwhatbuf2[100]; +static void permit(unsigned long pprefix, unsigned long pmask) { + int i, any; - if (argc < NARGS+1) { fputs("too few arguments\n",stderr); badusage(); } - if (argc > NARGS+1) { fputs("too many arguments\n",stderr); badusage(); } + assert(!(pprefix & ~pmask)); - carg= *++argv; - eat_prefixmask(&carg,"base", 0UL,0UL, 0,0, &baseprefix, &basemask, &baselen); + if (!proto) fputs("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; iparent) { + if (!strcmp(cpp->filename,filename)) + badusage("recursive configuration file `%s'",filename); + } + + file= fopen(filename,"r"); + if (!file) + badusage("cannot open configuration file `%s': %s", filename, strerror(errno)); + + if (!proto) printf("config file `%s':\n",filename); + + npp.parent= cpplace; + npp.filename= filename; + npp.lineno= 0; + cpplace= &npp; + + while (fgets(buf, sizeof(buf), file)) { + npp.lineno++; + l= strlen(buf); + if (!l) continue; + + truncated= (buf[l-1] != '\n'); + while (l>0 && isspace((unsigned char) buf[l-1])) l--; + if (!l) continue; + buf[l]= 0; + + if (truncated) { + while ((c= getc(file)) != EOF && c != '\n'); + if (c == EOF) break; + } + + pconfig(buf,truncated); + } + if (ferror(file)) + badusage("failed while reading configuration file: %s", strerror(errno)); + + cpplace= npp.parent; +} + +static void pconfig(const char *configstr, int truncated) { + unsigned long fgid, tgid, pprefix, pmask; + int plen; + char ptxt[ATXTLEN]; + const char *gidlist; + + switch (configstr[0]) { + case '*': + if (strcmp(configstr,"*")) badusage("`*' directive must be only thing on line"); + permit(0UL,0UL); + return; + + case '#': + return; + + case '/': case '.': + if (truncated) badusage("filename too long (`%.100s...')",configstr); + pfile(configstr); + return; + + default: + if (!isdigit((unsigned char)configstr[0])) + badusage("unknown configuration directive"); + + fgid= eat_number(&configstr,"gid", 0,gidmaxval, ",",0); + eat_prefixmask(&configstr,"permitted-prefix", ",",0, &pprefix,&pmask,&plen); + if (!configstr && truncated) badusage("gid,prefix/len,... spec too long"); + + if (!proto) printf(" %5lu,%s/%d: ", fgid, ip2txt(pprefix,ptxt), plen); + + gidlist= getenv("USERV_GID"); + if (!gidlist) fatal("USERV_GID not set"); for (;;) { - if (!*carg) fatal("no gid authorised"); - gidmin= eat_number(&carg,"gid-min", 0,gidmaxval, "-",0); - gidmax= eat_number(&carg,"gid-max", gidmin,gidmaxval, ":",0); - gidadd= eat_number(&carg,"gid-add", 0,gidmaxval, "/",0); - gidlen= eat_number(&carg,"gid-len", 0,32-baselen, 0,0); - - gidlist= getenv("USERV_GID"); - if (!gidlist) fatal("USERV_GID not set"); - while (gidlist) { - tgid= eat_number(&gidlist,"userv_gid", 0,gidmaxval, " ",0); - if (tgid >= gidmin && tgid <= gidmax) goto gid_found; + if (!gidlist) { + if (!proto) printf("no matching gid\n"); + return; } + tgid= eat_number(&gidlist,"userv-gid", 0,gidmaxval, " ",0); + if (tgid == fgid) break; } - gid_found: - tgid += gidadd; - tgid &= ((1UL << gidlen) - 1); - baselen += gidlen; - baseprefix |= (tgid << (32-baselen)); - basemask = (~0UL << (32-baselen)); - } else { - tgid= 0; + permit(pprefix,pmask); + return; } +} + +static void checkallow(int allow, const char *what, + const char *prefixtxt, const char *masktxt) { + if (allow) return; + fprintf(stderr,"userv-ipif service: access denied for %s, %s/%s\n", + what, prefixtxt, masktxt); + allallow= 0; +} + +static void parseargs(int argc, const char *const *argv) { + unsigned long routeaddr, routemask; + const char *carg; + const char *const *cprotop; + int i; + char erwhatbuf[100], erwhatbuf2[100]; + + if (argc < NARGS+1) { badusage("too few arguments"); } + if (argc > NARGS+1) { badusage("too many arguments"); } + + configstr= *++argv; carg= *++argv; + if (strcmp(carg,"--")) badusage("separator argument `--' not found, got `%s'",carg); - localaddr= eat_addr(&carg,"local-addr", baseprefix,basemask, ",",0); - peeraddr= eat_addr(&carg,"peer-addr", baseprefix,basemask, ",",0); + carg= *++argv; + localaddr= eat_addr(&carg,"local-addr", ",",0); + peeraddr= eat_addr(&carg,"peer-addr", ",",0); mtu= eat_number(&carg,"mtu", 576,65536, ",",0); + localallow= peerallow= 0; if (!strcmp(carg,"debug")) { proto= 0; @@ -239,55 +373,76 @@ int main(int argc, const char *const *argv) { carg= *++argv; for (nexroutes=0; - *carg; - carg++, nexroutes++) { - if (nexroutes == MAXEXROUTES) { - fprintf(stderr,"only %d extra routes allowed\n",MAXEXROUTES); - fatal("too many extra routes"); - } - sprintf(erwhatbuf,"route %d",nexroutes+1); + carg; + nexroutes++) { + if (nexroutes == MAXEXROUTES) + fatal("too many extra routes (only %d allowed)",MAXEXROUTES); + sprintf(erwhatbuf,"route#%d",nexroutes); - eat_prefixmask(&carg,erwhatbuf, baseprefix,basemask, ",",0, &routeaddr,&routemask,0); - addrnet_mustdiffer(erwhatbuf,routeaddr,routemask, "local-addr",localaddr,~0UL); - addrnet_mustdiffer(erwhatbuf,routeaddr,routemask, "peer-addr",peeraddr,~0UL); + eat_prefixmask(&carg,erwhatbuf, ",",0, &routeaddr,&routemask,0); + if (routemask == ~0UL) { + addrnet_mustdiffer(erwhatbuf,routeaddr,routemask, "local-addr",localaddr,~0UL); + addrnet_mustdiffer(erwhatbuf,routeaddr,routemask, "peer-addr",peeraddr,~0UL); + } for (i=0; i