-start nss

1 files changed, 286 insertions, 0 deletions

diff --git a/src/gns/nss/nss_gns.c b/src/gns/nss/nss_gns.c
new file mode 100644
index 000000000..054f20b13
--- /dev/null
+++ b/src/gns/nss/nss_gns.c
@@ -0,0 +1,286 @@
+/***
+    This file is part of nss-gns.
+
+    Parts taken from: nss.c in nss-mdns
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <nss.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#elif defined(NSS_IPV4_ONLY)
+#define _nss_mdns_gethostbyname2_r _nss_gns4_minimal_gethostbyname2_r
+#define _nss_mdns_gethostbyname_r  _nss_gns4_minimal_gethostbyname_r
+#define _nss_mdns_gethostbyaddr_r  _nss_gns4_minimal_gethostbyaddr_r
+#elif defined(NSS_IPV6_ONLY)
+#define _nss_mdns_gethostbyname2_r _nss_gns6_gethostbyname2_r
+#define _nss_mdns_gethostbyname_r  _nss_gns6_gethostbyname_r
+#define _nss_mdns_gethostbyaddr_r  _nss_gns6_gethostbyaddr_r
+#else
+#define _nss_mdns_gethostbyname2_r _nss_gns_gethostbyname2_r
+#define _nss_mdns_gethostbyname_r  _nss_gns_gethostbyname_r
+#define _nss_mdns_gethostbyaddr_r  _nss_gns_gethostbyaddr_r
+#endif
+
+/* Maximum number of entries to return */
+#define MAX_ENTRIES 16
+
+#define ALIGN(idx) do { \
+  if (idx % sizeof(void*)) \
+    idx += (sizeof(void*) - idx % sizeof(void*)); /* Align on 32 bit boundary */ \
+} while(0)
+
+struct userdata {
+    int count;
+    int data_len; /* only valid when doing reverse lookup */
+    union  {
+        ipv4_address_t ipv4[MAX_ENTRIES];
+        ipv6_address_t ipv6[MAX_ENTRIES];
+        char *name[MAX_ENTRIES];
+    } data;
+};
+
+#ifndef NSS_IPV6_ONLY
+static void ipv4_callback(const ipv4_address_t *ipv4, void *userdata) {
+    struct userdata *u = userdata;
+    assert(ipv4 && userdata);
+
+    if (u->count >= MAX_ENTRIES)
+        return;
+
+    u->data.ipv4[u->count++] = *ipv4;
+    u->data_len += sizeof(ipv4_address_t);
+}
+#endif
+
+#ifndef NSS_IPV4_ONLY
+static void ipv6_callback(const ipv6_address_t *ipv6, void *userdata) {
+    struct userdata *u = userdata;
+    assert(ipv6 && userdata);
+
+    if (u->count >= MAX_ENTRIES)
+        return;
+
+    u->data.ipv6[u->count++] = *ipv6;
+    u->data_len += sizeof(ipv6_address_t);
+}
+#endif
+
+static void name_callback(const char*name, void *userdata) {
+    struct userdata *u = userdata;
+    assert(name && userdata);
+
+    if (u->count >= MAX_ENTRIES)
+        return;
+
+    u->data.name[u->count++] = strdup(name);
+    u->data_len += strlen(name)+1;
+}
+
+static int ends_with(const char *name, const char* suffix) {
+    size_t ln, ls;
+    assert(name);
+    assert(suffix);
+
+    if ((ls = strlen(suffix)) > (ln = strlen(name)))
+        return 0;
+
+    return strcasecmp(name+ln-ls, suffix) == 0;
+}
+
+static int verify_name_allowed(const char *name) {
+    return ends_with(name, ".gnunet") || ends_with(name, ".zkey"); 
+}
+
+enum nss_status _nss_gns_gethostbyname2_r(
+    const char *name,
+    int af,
+    struct hostent * result,
+    char *buffer,
+    size_t buflen,
+    int *errnop,
+    int *h_errnop) {
+
+    struct userdata u;
+    enum nss_status status = NSS_STATUS_UNAVAIL;
+    int i;
+    size_t address_length, l, idx, astart;
+    void (*ipv4_func)(const ipv4_address_t *ipv4, void *userdata);
+    void (*ipv6_func)(const ipv6_address_t *ipv6, void *userdata);
+    int name_allowed;
+
+    if (af == AF_UNSPEC)
+#ifdef NSS_IPV6_ONLY
+        af = AF_INET6;
+#else
+        af = AF_INET;
+#endif
+
+#ifdef NSS_IPV4_ONLY
+    if (af != AF_INET) 
+#elif NSS_IPV6_ONLY
+    if (af != AF_INET6)
+#else        
+    if (af != AF_INET && af != AF_INET6)
+#endif        
+    {    
+        *errnop = EINVAL;
+        *h_errnop = NO_RECOVERY;
+
+        goto finish;
+    }
+
+    address_length = af == AF_INET ? sizeof(ipv4_address_t) : sizeof(ipv6_address_t);
+    if (buflen <
+        sizeof(char*)+    /* alias names */
+        strlen(name)+1)  {   /* official name */
+        
+        *errnop = ERANGE;
+        *h_errnop = NO_RECOVERY;
+        status = NSS_STATUS_TRYAGAIN;
+        
+        goto finish;
+    }
+    
+    u.count = 0;
+    u.data_len = 0;
+
+#ifdef NSS_IPV6_ONLY
+    ipv4_func = NULL;
+#else
+    ipv4_func = af == AF_INET ? ipv4_callback : NULL;
+#endif
+
+#ifdef NSS_IPV4_ONLY
+    ipv6_func = NULL;
+#else
+    ipv6_func = af == AF_INET6 ? ipv6_callback : NULL;
+#endif
+
+#ifdef ENABLE_GNS
+    name_allowed = verify_name_allowed(name);
+    
+    if (gns_works && name_allowed) {
+        int r;
+
+        if ((r = gns_resolve_name(af, name, data)) < 0)
+            gns_works = 0;
+        else if (r == 0) {
+            if (af == AF_INET && ipv4_func)
+                ipv4_func((ipv4_address_t*) data, &u);
+            if (af == AF_INET6 && ipv6_func)
+                ipv6_func((ipv6_address_t*)data, &u);
+        } else
+            status = NSS_STATUS_NOTFOUND;
+    }
+
+#endif /* ENABLE_GNS */
+
+    if (u.count == 0) {
+        *errnop = ETIMEDOUT;
+        *h_errnop = HOST_NOT_FOUND;
+        goto finish;
+    }
+    
+    /* Alias names */
+    *((char**) buffer) = NULL;
+    result->h_aliases = (char**) buffer;
+    idx = sizeof(char*);
+    
+    /* Official name */
+    strcpy(buffer+idx, name); 
+    result->h_name = buffer+idx;
+    idx += strlen(name)+1;
+
+    ALIGN(idx);
+    
+    result->h_addrtype = af;
+    result->h_length = address_length;
+    
+    /* Check if there's enough space for the addresses */
+    if (buflen < idx+u.data_len+sizeof(char*)*(u.count+1)) {
+        *errnop = ERANGE;
+        *h_errnop = NO_RECOVERY;
+        status = NSS_STATUS_TRYAGAIN;
+        goto finish;
+    }
+
+    /* Addresses */
+    astart = idx;
+    l = u.count*address_length;
+    memcpy(buffer+astart, &u.data, l);
+    /* address_length is a multiple of 32bits, so idx is still aligned
+     * correctly */
+    idx += l;
+
+    /* Address array address_lenght is always a multiple of 32bits */
+    for (i = 0; i < u.count; i++)
+        ((char**) (buffer+idx))[i] = buffer+astart+address_length*i;
+    ((char**) (buffer+idx))[i] = NULL;
+    result->h_addr_list = (char**) (buffer+idx);
+
+    status = NSS_STATUS_SUCCESS;
+    
+finish:
+    return status;
+}
+
+enum nss_status _nss_gns_gethostbyname_r (
+    const char *name,
+    struct hostent *result,
+    char *buffer,
+    size_t buflen,
+    int *errnop,
+    int *h_errnop) {
+
+    return _nss_gns_gethostbyname2_r(
+        name,
+        AF_UNSPEC,
+        result,
+        buffer,
+        buflen,
+        errnop,
+        h_errnop);
+}
+
+enum nss_status _nss_gns_gethostbyaddr_r(
+    const void* addr,
+    int len,
+    int af,
+    struct hostent *result,
+    char *buffer,
+    size_t buflen,
+    int *errnop,
+    int *h_errnop) {
+
+    /* we dont do this */
+    
+    struct userdata u;
+    enum nss_status status = NSS_STATUS_UNAVAIL;
+    int r;
+    size_t address_length, idx, astart;
+    
+    *errnop = EINVAL;
+    *h_errnop = NO_RECOVERY;
+
+    u.count = 0;
+    u.data_len = 0;
+
+    /* Check for address types */
+
+    *h_errnop = NO_RECOVERY;
+
+    status = NSS_STATUS_NOTFOUND;
+    return status;
+}
+