diff options
| -rw-r--r-- | lib/libc/net/rcmd.c | 149 |
1 files changed, 94 insertions, 55 deletions
diff --git a/lib/libc/net/rcmd.c b/lib/libc/net/rcmd.c index e0310031b0e..3db3d86400b 100644 --- a/lib/libc/net/rcmd.c +++ b/lib/libc/net/rcmd.c @@ -57,9 +57,11 @@ static char *rcsid = "$NetBSD: rcmd.c,v 1.12 1995/06/03 22:33:34 mycroft Exp $"; #include <stdio.h> #include <ctype.h> #include <string.h> +#include <syslog.h> int __ivaliduser __P((FILE *, u_long, const char *, const char *)); -static int __icheckhost __P((u_long, const char *)); +static int __icheckhost __P((u_int32_t, const char *)); +static char *__gethostloop __P((u_int32_t)); int rcmd(ahost, rport, locuser, remuser, cmd, fd2p) @@ -253,7 +255,7 @@ ruserok(rhost, superuser, ruser, luser) char **ap; int i; #define MAXADDRS 35 - u_long addrs[MAXADDRS + 1]; + u_int32_t addrs[MAXADDRS + 1]; if ((hp = gethostbyname(rhost)) == NULL) return (-1); @@ -262,7 +264,7 @@ ruserok(rhost, superuser, ruser, luser) addrs[i] = 0; for (i = 0; i < MAXADDRS && addrs[i]; i++) - if (iruserok(addrs[i], superuser, ruser, luser) == 0) + if (iruserok((u_long)addrs[i], superuser, ruser, luser) == 0) return (0); return (-1); } @@ -352,9 +354,9 @@ again: * Returns 0 if ok, -1 if not ok. */ int -__ivaliduser(hostf, raddr, luser, ruser) +__ivaliduser(hostf, raddrl, luser, ruser) FILE *hostf; - u_long raddr; + u_long raddrl; const char *luser, *ruser; { register char *user, *p; @@ -362,9 +364,9 @@ __ivaliduser(hostf, raddr, luser, ruser) char buf[MAXHOSTNAMELEN + 128]; /* host + login */ const char *auser, *ahost; int hostok, userok; - char rhost[MAXHOSTNAMELEN]; - struct hostent *hp; + char *rhost = (char *)-1; char domain[MAXHOSTNAMELEN]; + u_int32_t raddr = (u_int32_t)raddrl; getdomainname(domain, sizeof(domain)); @@ -372,7 +374,8 @@ __ivaliduser(hostf, raddr, luser, ruser) p = buf; /* Skip lines that are too long. */ if (strchr(p, '\n') == NULL) { - while ((ch = getc(hostf)) != '\n' && ch != EOF); + while ((ch = getc(hostf)) != '\n' && ch != EOF) + ; continue; } while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { @@ -397,25 +400,24 @@ __ivaliduser(hostf, raddr, luser, ruser) auser = *user ? user : luser; ahost = buf; - if ((hp = gethostbyaddr((char *) &raddr, - sizeof(raddr), AF_INET)) == NULL) { - abort(); - return -1; - } - (void) strncpy(rhost, hp->h_name, sizeof(rhost)); - rhost[sizeof(rhost) - 1] = '\0'; - + /* + * innetgr() must lookup a hostname (we do not attempt + * to change the semantics so that netgroups may have + * #.#.#.# addresses in the list.) + */ if (ahost[0] == '+') switch (ahost[1]) { case '\0': hostok = 1; break; - case '@': - hostok = innetgr(&ahost[2], rhost, NULL, - domain); + if (rhost == (char *)-1) + rhost = __gethostloop(raddr); + hostok = 0; + if (rhost) + hostok = innetgr(&ahost[2], rhost, + NULL, domain); break; - default: hostok = __icheckhost(raddr, &ahost[1]); break; @@ -425,12 +427,14 @@ __ivaliduser(hostf, raddr, luser, ruser) case '\0': hostok = -1; break; - case '@': - hostok = -innetgr(&ahost[2], rhost, NULL, - domain); + if (rhost == (char *)-1) + rhost = __gethostloop(raddr); + hostok = 0; + if (rhost) + hostok = -innetgr(&ahost[2], rhost, + NULL, domain); break; - default: hostok = -__icheckhost(raddr, &ahost[1]); break; @@ -444,14 +448,12 @@ __ivaliduser(hostf, raddr, luser, ruser) case '\0': userok = 1; break; - case '@': userok = innetgr(&auser[2], NULL, ruser, - domain); + domain); break; - default: - userok = strcmp(ruser, &auser[1]) == 0; + userok = strcmp(ruser, &auser[1]) ? 0 : 1; break; } else if (auser[0] == '-') @@ -459,59 +461,96 @@ __ivaliduser(hostf, raddr, luser, ruser) case '\0': userok = -1; break; - case '@': userok = -innetgr(&auser[2], NULL, ruser, - domain); + domain); break; - default: - userok = -(strcmp(ruser, &auser[1]) == 0); + userok = strcmp(ruser, &auser[1]) ? 0 : -1; break; } else - userok = strcmp(ruser, auser) == 0; + userok = strcmp(ruser, auser) ? 0 : 1; /* Check if one component did not match */ if (hostok == 0 || userok == 0) continue; /* Check if we got a forbidden pair */ - if (userok == -1 || hostok == -1) - return -1; + if (userok <= -1 || hostok <= -1) + return (-1); /* Check if we got a valid pair */ - if (hostok == 1 && userok == 1) - return 0; + if (hostok >= 1 && userok >= 1) + return (0); } - return -1; + return (-1); } /* - * Returns "true" if match, 0 if no match. + * Returns "true" if match, 0 if no match. If we do not find any + * semblance of an A->PTR->A loop, allow a simple #.#.#.# match to work. */ static int __icheckhost(raddr, lhost) - u_long raddr; + u_int32_t raddr; const char *lhost; { register struct hostent *hp; - register u_long laddr; register char **pp; + struct in_addr in; + + hp = gethostbyname(lhost); + if (hp != NULL) { + /* Spin through ip addresses. */ + for (pp = hp->h_addr_list; *pp; ++pp) + if (!bcmp(&raddr, *pp, sizeof(raddr))) + return (1); + } - /* Try for raw ip address first. */ - if (isdigit(*lhost) && (long)(laddr = inet_addr(lhost)) != -1) - return (raddr == laddr); - - /* Better be a hostname. */ - if ((hp = gethostbyname(lhost)) == NULL) - return (0); - - /* Spin through ip addresses. */ - for (pp = hp->h_addr_list; *pp; ++pp) - if (!bcmp(&raddr, *pp, sizeof(u_long))) - return (1); - - /* No match. */ + in.s_addr = raddr; + if (strcmp(lhost, inet_ntoa(in)) == 0) + return (1); return (0); } + +/* + * Return the hostname associated with the supplied address. + * Do a reverse lookup as well for security. If a loop cannot + * be found, pack the result of inet_ntoa() into the string. + */ +static char * +__gethostloop(raddr) + u_int32_t raddr; +{ + static char remotehost[MAXHOSTNAMELEN]; + struct hostent *hp; + struct in_addr in; + + hp = gethostbyaddr((char *) &raddr, sizeof(raddr), AF_INET); + if (hp == NULL) + return (NULL); + + /* + * Look up the name and check that the supplied + * address is in the list + */ + strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1); + remotehost[sizeof(remotehost) - 1] = '\0'; + hp = gethostbyname(remotehost); + if (hp == NULL) + return (NULL); + + for (; hp->h_addr_list[0] != NULL; hp->h_addr_list++) + if (!bcmp(hp->h_addr_list[0], (caddr_t)&raddr, sizeof(raddr))) + return (remotehost); + + /* + * either the DNS adminstrator has made a configuration + * mistake, or someone has attempted to spoof us + */ + in.s_addr = raddr; + syslog(LOG_NOTICE, "rcmd: address %s not listed for host %s", + inet_ntoa(in), hp->h_name); + return (NULL); +} |