nwrap: Try different backends in gethostbyaddr

Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/src/nss_wrapper.c b/src/nss_wrapper.c
index 1bcd3b1b72daf83c2598d1269cc583fd0fd61d55..269701079eb7e7e7d0ea984ca5bc4be286b5ee35 100644 (file)
--- a/src/nss_wrapper.c
+++ b/src/nss_wrapper.c
@@ -395,6 +395,10 @@ struct nwrap_module_nss_fns {
        NSS_STATUS (*_nss_getgrent_r)(struct group *result, char *buffer,
                                      size_t buflen, int *errnop);
        NSS_STATUS (*_nss_endgrent)(void);
+       NSS_STATUS (*_nss_gethostbyaddr_r)(const void *addr, socklen_t addrlen,
+                                          int af, struct hostent *result,
+                                          char *buffer, size_t buflen,
+                                          int *errnop, int *h_errnop);
 };
 
 struct nwrap_backend {
@@ -440,6 +444,9 @@ struct nwrap_ops {
                                         struct group *grdst, char *buf,
                                         size_t buflen, struct group **grdstp);
        void            (*nw_endgrent)(struct nwrap_backend *b);
+       struct hostent *(*nw_gethostbyaddr)(struct nwrap_backend *b,
+                                           const void *addr,
+                                           socklen_t len, int type);
 };
 
 /* Public prototypes */
@@ -485,6 +492,9 @@ static int nwrap_files_getgrent_r(struct nwrap_backend *b,
                                  struct group *grdst, char *buf,
                                  size_t buflen, struct group **grdstp);
 static void nwrap_files_endgrent(struct nwrap_backend *b);
+static struct hostent *nwrap_files_gethostbyaddr(struct nwrap_backend *b,
+                                                const void *addr,
+                                                socklen_t len, int type);
 
 /* prototypes for module backend */
 
@@ -522,6 +532,9 @@ static void nwrap_module_setgrent(struct nwrap_backend *b);
 static void nwrap_module_endgrent(struct nwrap_backend *b);
 static int nwrap_module_initgroups(struct nwrap_backend *b,
                                   const char *user, gid_t group);
+static struct hostent *nwrap_module_gethostbyaddr(struct nwrap_backend *b,
+                                                 const void *addr,
+                                                 socklen_t len, int type);
 
 struct nwrap_ops nwrap_files_ops = {
        .nw_getpwnam    = nwrap_files_getpwnam,
@@ -541,6 +554,7 @@ struct nwrap_ops nwrap_files_ops = {
        .nw_getgrent    = nwrap_files_getgrent,
        .nw_getgrent_r  = nwrap_files_getgrent_r,
        .nw_endgrent    = nwrap_files_endgrent,
+       .nw_gethostbyaddr       = nwrap_files_gethostbyaddr,
 };
 
 struct nwrap_ops nwrap_module_ops = {
@@ -561,6 +575,7 @@ struct nwrap_ops nwrap_module_ops = {
        .nw_getgrent    = nwrap_module_getgrent,
        .nw_getgrent_r  = nwrap_module_getgrent_r,
        .nw_endgrent    = nwrap_module_endgrent,
+       .nw_gethostbyaddr       = nwrap_module_gethostbyaddr,
 };
 
 struct nwrap_libc {
@@ -1475,6 +1490,8 @@ static struct nwrap_module_nss_fns *nwrap_load_module_fns(struct nwrap_backend *
                nwrap_load_module_fn(b, "getgrent_r");
        *(void **)(&fns->_nss_endgrent) =
                nwrap_load_module_fn(b, "endgrent");
+       *(void **)(&fns->_nss_gethostbyaddr_r) =
+               nwrap_load_module_fn(b, "gethostbyaddr_r");
 
        return fns;
 }
@@ -3785,7 +3802,8 @@ static int nwrap_files_getaddrinfo(const char *name,
        return rc;
 }
 
-static struct hostent *nwrap_files_gethostbyaddr(const void *addr,
+static struct hostent *nwrap_files_gethostbyaddr(struct nwrap_backend *b,
+                                                const void *addr,
                                                 socklen_t len, int type)
 {
        struct hostent *he;
@@ -3795,6 +3813,7 @@ static struct hostent *nwrap_files_gethostbyaddr(const void *addr,
        size_t i;
        bool ok;
 
+       (void) b; /* unused */
        (void) len; /* unused */
 
        ok = nwrap_files_cache_reload(nwrap_he_global.cache);
@@ -3831,15 +3850,23 @@ static int nwrap_gethostbyaddr_r(const void *addr, socklen_t len, int type,
                                 char *buf, size_t buflen,
                                 struct hostent **result, int *h_errnop)
 {
-       *result = nwrap_files_gethostbyaddr(addr, len, type);
+       size_t i;
+       for (i=0; i < nwrap_main_global->num_backends; i++) {
+               struct nwrap_backend *b = &nwrap_main_global->backends[i];
+               *result = b->ops->nw_gethostbyaddr(b, addr, len, type);
+               if (*result != NULL) {
+                       break;
+               }
+       }
+
        if (*result != NULL) {
                memset(buf, '\0', buflen);
                *ret = **result;
                return 0;
-       } else {
-               *h_errnop = h_errno;
-               return -1;
        }
+
+       *h_errnop = h_errno;
+       return -1;
 }
 
 int gethostbyaddr_r(const void *addr, socklen_t len, int type,
@@ -4336,6 +4363,47 @@ static void nwrap_module_endgrent(struct nwrap_backend *b)
        b->fns->_nss_endgrent();
 }
 
+static struct hostent *nwrap_module_gethostbyaddr(struct nwrap_backend *b,
+                                                 const void *addr,
+                                                 socklen_t len, int type)
+{
+       static struct hostent he;
+       static char *buf = NULL;
+       static size_t buflen = 1000;
+       NSS_STATUS status;
+
+       if (b->fns->_nss_gethostbyaddr_r == NULL) {
+               return NULL;
+       }
+
+       if (buf == NULL) {
+               buf = (char *)malloc(buflen);
+               if (buf == NULL) {
+                       return NULL;
+               }
+       }
+again:
+       status = b->fns->_nss_gethostbyaddr_r(addr, len, type, &he,
+                                             buf, buflen, &errno, &h_errno);
+       if (status == NSS_STATUS_TRYAGAIN) {
+               buflen *= 2;
+               buf = (char *)realloc(buf, buflen);
+               if (buf == NULL) {
+                       return NULL;
+               }
+               goto again;
+       }
+       if (status == NSS_STATUS_NOTFOUND) {
+               SAFE_FREE(buf);
+               return NULL;
+       }
+       if (status != NSS_STATUS_SUCCESS) {
+               SAFE_FREE(buf);
+               return NULL;
+       }
+       return &he;
+}
+
 /****************************************************************************
  *   GETPWNAM
  ***************************************************************************/
@@ -5185,7 +5253,18 @@ struct hostent *gethostbyname2(const char *name, int af)
 static struct hostent *nwrap_gethostbyaddr(const void *addr,
                                           socklen_t len, int type)
 {
-       return nwrap_files_gethostbyaddr(addr, len, type);
+       size_t i;
+       struct hostent *he = NULL;
+
+       for (i=0; i < nwrap_main_global->num_backends; i++) {
+               struct nwrap_backend *b = &nwrap_main_global->backends[i];
+               he = b->ops->nw_gethostbyaddr(b, addr, len, type);
+               if (he != NULL) {
+                       return he;
+               }
+       }
+
+       return NULL;
 }
 
 struct hostent *gethostbyaddr(const void *addr,
@@ -5531,6 +5610,7 @@ static int nwrap_getnameinfo(const struct sockaddr *sa, socklen_t salen,
        socklen_t addrlen;
        uint16_t port;
        sa_family_t type;
+       size_t i;
 
        if (sa == NULL || salen < sizeof(sa_family_t)) {
                return EAI_FAMILY;
@@ -5585,7 +5665,13 @@ static int nwrap_getnameinfo(const struct sockaddr *sa, socklen_t salen,
        if (host != NULL) {
                he = NULL;
                if ((flags & NI_NUMERICHOST) == 0) {
-                       he = nwrap_files_gethostbyaddr(addr, addrlen, type);
+                       for (i=0; i < nwrap_main_global->num_backends; i++) {
+                               struct nwrap_backend *b = &nwrap_main_global->backends[i];
+                               he = b->ops->nw_gethostbyaddr(b, addr, addrlen, type);
+                               if (he != NULL) {
+                                       break;
+                               }
+                       }
                        if ((flags & NI_NAMEREQD) && (he == NULL || he->h_name == NULL))
                                return EAI_NONAME;
                }