diff options
| -rw-r--r-- | ChangeLog | 11 | ||||
| -rw-r--r-- | support/export/hostname.c | 52 | ||||
| -rw-r--r-- | support/include/misc.h | 1 | ||||
| -rw-r--r-- | utils/mountd/auth.c | 79 |
4 files changed, 77 insertions, 66 deletions
@@ -1,3 +1,14 @@ +2003-05-21 NeilBrown <neilb@cse.unsw.edu.au> + + * support/export/hostname.c(get_reliable_hostbyaddr): new function + to get host name from address with full checking of authenticity. + * support/include/misc.h: declare above function + * utils/mountd/auth.c(auth_authenticate_internal): remove all + logic for authenticating address. + * utils/mountd/auth.c(auth_authenticate): call new + get_reliable_hostbyaddr to to hostname lookup before calling _internal. + + 2003-03-30 NeilBrown <neilb@cse.unsw.edu.au> * tools/rpcgen/rpc_main.c(find_cpp): removed diff --git a/support/export/hostname.c b/support/export/hostname.c index 299fe99..f88e0a4 100644 --- a/support/export/hostname.c +++ b/support/export/hostname.c @@ -16,6 +16,7 @@ #include <netinet/in.h> #include <arpa/inet.h> #include <stdlib.h> +#include <xlog.h> #ifdef TEST #define xmalloc malloc #else @@ -216,6 +217,57 @@ matchhostname (const char *h1, const char *h2) return status; } + +/* Map IP to hostname, and then map back to addr to make sure it is a + * reliable hostname + */ +struct hostent * +get_reliable_hostbyaddr(const char *addr, int len, int type) +{ + struct hostent *hp; + + char **sp; + struct hostent *forward = NULL; + char *tmpname; + + hp = gethostbyaddr(addr, len , type); + if (!hp) + return hp; + + /* must make sure the hostent is authorative. */ + + hp = hostent_dup (hp); + tmpname = xstrdup((hp)->h_name); + if (tmpname) { + forward = gethostbyname(tmpname); + free(tmpname); + } + if (forward) { + /* now make sure the "addr" is in the list */ + for (sp = forward->h_addr_list ; *sp ; sp++) { + if (memcmp(*sp, addr, forward->h_length)==0) + break; + } + + if (!*sp) { + /* it was a FAKE */ + xlog(L_WARNING, "Fake hostname %s for %s - forward lookup doesn't match reverse", + forward->h_name, inet_ntoa(*(struct in_addr*)addr)); + return NULL; + } + free (hp); + hp = hostent_dup (forward); + } + else { + /* never heard of it. misconfigured DNS? */ + xlog(L_WARNING, "Fake hostname %s for %s - forward lookup doesn't exist", + forward->h_name, inet_ntoa(*(struct in_addr*)addr)); + return NULL; + } + return hp; +} + + #ifdef TEST void print_host (struct hostent *hp) diff --git a/support/include/misc.h b/support/include/misc.h index a3cdcfd..7d099d0 100644 --- a/support/include/misc.h +++ b/support/include/misc.h @@ -20,5 +20,6 @@ int matchhostname(const char *h1, const char *h2); struct hostent; struct hostent *hostent_dup(struct hostent *hp); struct hostent *get_hostent (const char *addr, int len, int type); +struct hostent *get_reliable_hostbyaddr(const char *addr, int len, int type); #endif /* MISC_H */ diff --git a/utils/mountd/auth.c b/utils/mountd/auth.c index d88c46f..eb9cdeb 100644 --- a/utils/mountd/auth.c +++ b/utils/mountd/auth.c @@ -25,15 +25,10 @@ enum auth_error no_entry, not_exported, illegal_port, - faked_hostent, - no_forward_dns, success }; static void auth_fixpath(char *path); -static nfs_export* auth_authenticate_internal - (char *what, struct sockaddr_in *caller, char *path, - struct hostent **hpp, enum auth_error *error); static char *export_file = NULL; void @@ -66,56 +61,12 @@ auth_reload() static nfs_export * auth_authenticate_internal(char *what, struct sockaddr_in *caller, - char *path, struct hostent **hpp, + char *path, struct hostent *hp, enum auth_error *error) { - struct in_addr addr = caller->sin_addr; nfs_export *exp; - if (path[0] != '/') { - *error = bad_path; - return NULL; - } - auth_fixpath(path); - - if (!(*hpp = gethostbyaddr((const char *)&addr, sizeof(addr), AF_INET))) - *hpp = get_hostent((const char *)&addr, sizeof(addr), - AF_INET); - else { - /* must make sure the hostent is authorative. */ - char **sp; - struct hostent *forward = NULL; - char *tmpname; - - *hpp = hostent_dup (*hpp); - tmpname = xstrdup((*hpp)->h_name); - if (tmpname) { - forward = gethostbyname(tmpname); - free(tmpname); - } - if (forward) { - /* now make sure the "addr" is in the list */ - for (sp = forward->h_addr_list ; *sp ; sp++) { - if (memcmp(*sp, &addr, forward->h_length)==0) - break; - } - - if (!*sp) { - /* it was a FAKE */ - *error = faked_hostent; - return NULL; - } - free (*hpp); - *hpp = hostent_dup (forward); - } - else { - /* never heard of it. misconfigured DNS? */ - *error = no_forward_dns; - return NULL; - } - } - - if (!(exp = export_find(*hpp, path))) { + if (!(exp = export_find(hp, path))) { *error = no_entry; return NULL; } @@ -154,15 +105,20 @@ auth_authenticate(char *what, struct sockaddr_in *caller, char *path) strncpy(epath, path, sizeof (epath) - 1); epath[sizeof (epath) - 1] = '\0'; + auth_fixpath(epath); /* strip duplicate '/' etc */ + + hp = get_reliable_hostbyaddr((const char*)&caller->sin_addr, sizeof(struct in_addr), + AF_INET); + if (!hp) + hp = get_hostent((const char*)&caller->sin_addr, sizeof(struct in_addr), + AF_INET); + if (!hp) + return exp; /* Try the longest matching exported pathname. */ while (1) { - if (hp) { - free (hp); - hp = NULL; - } exp = auth_authenticate_internal(what, caller, epath, - &hp, &error); + hp, &error); if (exp || (error != not_exported && error != no_entry)) break; /* We have to treat the root, "/", specially. */ @@ -171,6 +127,7 @@ auth_authenticate(char *what, struct sockaddr_in *caller, char *path) if (p == epath) p++; *p = '\0'; } + free(hp); switch (error) { case bad_path: @@ -198,16 +155,6 @@ auth_authenticate(char *what, struct sockaddr_in *caller, char *path) what, hp->h_name, path, epath, ntohs(caller->sin_port)); break; - case faked_hostent: - xlog(L_WARNING, "refused %s request from %s (%s) for %s (%s): DNS forward lookup does't match with reverse", - what, inet_ntoa(addr), hp->h_name, path, epath); - break; - - case no_forward_dns: - xlog(L_WARNING, "refused %s request from %s (%s) for %s (%s): no DNS forward lookup", - what, inet_ntoa(addr), hp->h_name, path, epath); - break; - case success: xlog(L_NOTICE, "authenticated %s request from %s:%d for %s (%s)", what, hp->h_name, ntohs(caller->sin_port), path, epath); |