chiark / gitweb /
nss-myhostname: various modernizations
authorLennart Poettering <lennart@poettering.net>
Thu, 10 Jul 2014 17:55:53 +0000 (19:55 +0200)
committerLennart Poettering <lennart@poettering.net>
Thu, 10 Jul 2014 18:12:34 +0000 (20:12 +0200)
src/nss-myhostname/ifconf.h
src/nss-myhostname/netlink.c
src/nss-myhostname/nss-myhostname.c

index cd598d2..92f03b2 100644 (file)
 #include <assert.h>
 #include <sys/socket.h>
 
+#include "socket-util.h"
+
 struct address {
         unsigned char family;
-        uint8_t address[16];
+        union in_addr_union address;
         unsigned char scope;
         int ifindex;
 };
 
-#define _public_ __attribute__ ((visibility("default")))
-#define _hidden_ __attribute__ ((visibility("hidden")))
-
-int ifconf_acquire_addresses(struct address **_list, unsigned *_n_list) _hidden_;
-
 static inline size_t PROTO_ADDRESS_SIZE(int proto) {
         assert(proto == AF_INET || proto == AF_INET6);
 
         return proto == AF_INET6 ? 16 : 4;
 }
 
-static inline int address_compare(const void *_a, const void *_b) {
-        const struct address *a = _a, *b = _b;
-
-        /* Order lowest scope first, IPv4 before IPv6, lowest interface index first */
-
-        if (a->scope < b->scope)
-                return -1;
-        if (a->scope > b->scope)
-                return 1;
-
-        if (a->family == AF_INET && b->family == AF_INET6)
-                return -1;
-        if (a->family == AF_INET6 && b->family == AF_INET)
-                return 1;
-
-        if (a->ifindex < b->ifindex)
-                return -1;
-        if (a->ifindex > b->ifindex)
-                return 1;
-
-        return 0;
-}
+int ifconf_acquire_addresses(struct address **_list, unsigned *_n_list);
index b4a464c..e9518e3 100644 (file)
 #include "sd-rtnl.h"
 #include "rtnl-util.h"
 #include "macro.h"
-
 #include "ifconf.h"
 
+static int address_compare(const void *_a, const void *_b) {
+        const struct address *a = _a, *b = _b;
+
+        /* Order lowest scope first, IPv4 before IPv6, lowest interface index first */
+
+        if (a->scope < b->scope)
+                return -1;
+        if (a->scope > b->scope)
+                return 1;
+
+        if (a->family == AF_INET && b->family == AF_INET6)
+                return -1;
+        if (a->family == AF_INET6 && b->family == AF_INET)
+                return 1;
+
+        if (a->ifindex < b->ifindex)
+                return -1;
+        if (a->ifindex > b->ifindex)
+                return 1;
+
+        return 0;
+}
+
 int ifconf_acquire_addresses(struct address **_list, unsigned *_n_list) {
-        _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
         _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
-        sd_rtnl_message *m;
+        _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
         _cleanup_free_ struct address *list = NULL;
-        struct address *new_list = NULL;
-        unsigned n_list = 0;
+        size_t n_list = 0, n_allocated = 0;
+        sd_rtnl_message *m;
         int r;
 
         r = sd_rtnl_open(&rtnl, 0);
@@ -46,18 +67,11 @@ int ifconf_acquire_addresses(struct address **_list, unsigned *_n_list) {
         r = sd_rtnl_call(rtnl, req, 0, &reply);
         if (r < 0)
                 return r;
-        m = reply;
 
-        do {
-                uint16_t type;
-                unsigned char scope;
+        for (m = reply; m; m = sd_rtnl_message_next(m)) {
+                struct address *a;
                 unsigned char flags;
-                unsigned char family;
-                int ifindex;
-                union {
-                        struct in_addr in;
-                        struct in6_addr in6;
-                } address;
+                uint16_t type;
 
                 r = sd_rtnl_message_get_errno(m);
                 if (r < 0)
@@ -70,72 +84,66 @@ int ifconf_acquire_addresses(struct address **_list, unsigned *_n_list) {
                 if (type != RTM_NEWADDR)
                         continue;
 
-                r = sd_rtnl_message_addr_get_scope(m, &scope);
+                r = sd_rtnl_message_addr_get_flags(m, &flags);
                 if (r < 0)
                         return r;
 
-                if (scope == RT_SCOPE_HOST || scope == RT_SCOPE_NOWHERE)
+                if (flags & IFA_F_DEPRECATED)
                         continue;
 
-                r = sd_rtnl_message_addr_get_flags(m, &flags);
+                if (!GREEDY_REALLOC(list, n_allocated, n_list+1))
+                        return -ENOMEM;
+
+                a = list + n_list;
+
+                r = sd_rtnl_message_addr_get_scope(m, &a->scope);
                 if (r < 0)
                         return r;
 
-                if (flags & IFA_F_DEPRECATED)
+                if (a->scope == RT_SCOPE_HOST || a->scope == RT_SCOPE_NOWHERE)
                         continue;
 
-                r = sd_rtnl_message_addr_get_family(m, &family);
+                r = sd_rtnl_message_addr_get_family(m, &a->family);
                 if (r < 0)
                         return r;
 
-                switch (family) {
+                switch (a->family) {
+
                 case AF_INET:
-                        r = sd_rtnl_message_read_in_addr(m, IFA_LOCAL, &address.in);
+                        r = sd_rtnl_message_read_in_addr(m, IFA_LOCAL, &a->address.in);
                         if (r < 0) {
-                                r = sd_rtnl_message_read_in_addr(m, IFA_ADDRESS, &address.in);
+                                r = sd_rtnl_message_read_in_addr(m, IFA_ADDRESS, &a->address.in);
                                 if (r < 0)
                                         continue;
                         }
                         break;
+
                 case AF_INET6:
-                        r = sd_rtnl_message_read_in6_addr(m, IFA_LOCAL, &address.in6);
+                        r = sd_rtnl_message_read_in6_addr(m, IFA_LOCAL, &a->address.in6);
                         if (r < 0) {
-                                r = sd_rtnl_message_read_in6_addr(m, IFA_ADDRESS, &address.in6);
+                                r = sd_rtnl_message_read_in6_addr(m, IFA_ADDRESS, &a->address.in6);
                                 if (r < 0)
                                         continue;
                         }
                         break;
+
                 default:
                         continue;
                 }
 
-                r = sd_rtnl_message_addr_get_ifindex(m, &ifindex);
+                r = sd_rtnl_message_addr_get_ifindex(m, &a->ifindex);
                 if (r < 0)
                         return r;
 
-                new_list = realloc(list, (n_list+1) * sizeof(struct address));
-                if (!new_list)
-                        return -ENOMEM;
-                else
-                        list = new_list;
-
-                assert_cc(sizeof(address) <= 16);
-
-                list[n_list].family = family;
-                list[n_list].scope = scope;
-                memcpy(list[n_list].address, &address, sizeof(address));
-                list[n_list].ifindex = ifindex;
-
                 n_list++;
-
-        } while ((m = sd_rtnl_message_next(m)));
+        };
 
         if (n_list)
                 qsort(list, n_list, sizeof(struct address), address_compare);
 
-        *_n_list = n_list;
         *_list = list;
         list = NULL;
+        *_n_list = n_list;
 
         return 0;
 }
index 60e256d..9320e69 100644 (file)
@@ -98,32 +98,39 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
                 int *errnop, int *h_errnop,
                 int32_t *ttlp) {
 
-        unsigned lo_ifi;
-        char hn[HOST_NAME_MAX+1] = {};
-        const char *canonical = NULL;
-        size_t l, idx, ms;
-        char *r_name;
         struct gaih_addrtuple *r_tuple, *r_tuple_prev = NULL;
-        struct address *addresses = NULL, *a;
+        _cleanup_free_ struct address *addresses = NULL;
+        _cleanup_free_ char *hn = NULL;
+        const char *canonical = NULL;
         unsigned n_addresses = 0, n;
         uint32_t local_address_ipv4;
+        struct address *a;
+        size_t l, idx, ms;
+        char *r_name;
+        int lo_ifi;
 
-        if (strcasecmp(name, "localhost") == 0) {
+        assert(name);
+        assert(pat);
+        assert(buffer);
+        assert(errnop);
+        assert(h_errnop);
+
+        if (is_localhost(name)) {
                 /* We respond to 'localhost', so that /etc/hosts
                  * is optional */
 
                 canonical = "localhost";
                 local_address_ipv4 = htonl(INADDR_LOOPBACK);
         } else {
-                /* We respond to our local host name */
-
-                if (gethostname(hn, sizeof(hn)-1) < 0) {
-                        *errnop = errno;
+                hn = gethostname_malloc();
+                if (!hn) {
+                        *errnop = ENOMEM;
                         *h_errnop = NO_RECOVERY;
-                        return NSS_STATUS_UNAVAIL;
+                        return NSS_STATUS_TRYAGAIN;
                 }
 
-                if (strcasecmp(name, hn) != 0) {
+                /* We respond to our local host name, our our hostname suffixed with a single dot. */
+                if (!streq(name, hn) && !streq_ptr(startswith(name, hn), ".")) {
                         *errnop = ENOENT;
                         *h_errnop = HOST_NOT_FOUND;
                         return NSS_STATUS_NOTFOUND;
@@ -140,11 +147,10 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
         lo_ifi = n_addresses <= 0 ? if_nametoindex(LOOPBACK_INTERFACE) : 0;
 
         l = strlen(canonical);
-        ms = ALIGN(l+1)+ALIGN(sizeof(struct gaih_addrtuple))*(n_addresses > 0 ? n_addresses : 2);
+        ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * (n_addresses > 0 ? n_addresses : 2);
         if (buflen < ms) {
                 *errnop = ENOMEM;
                 *h_errnop = NO_RECOVERY;
-                free(addresses);
                 return NSS_STATUS_TRYAGAIN;
         }
 
@@ -184,7 +190,7 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
                 r_tuple->name = r_name;
                 r_tuple->family = a->family;
                 r_tuple->scopeid = a->ifindex;
-                memcpy(r_tuple->addr, a->address, 16);
+                memcpy(r_tuple->addr, &a->address, 16);
 
                 idx += ALIGN(sizeof(struct gaih_addrtuple));
                 r_tuple_prev = r_tuple;
@@ -202,8 +208,6 @@ enum nss_status _nss_myhostname_gethostbyname4_r(
         if (ttlp)
                 *ttlp = 0;
 
-        free(addresses);
-
         return NSS_STATUS_SUCCESS;
 }
 
@@ -224,6 +228,12 @@ static enum nss_status fill_in_hostent(
         struct address *a;
         unsigned n, c;
 
+        assert(canonical);
+        assert(result);
+        assert(buffer);
+        assert(errnop);
+        assert(h_errnop);
+
         alen = PROTO_ADDRESS_SIZE(af);
 
         for (a = addresses, n = 0, c = 0; n < n_addresses; a++, n++)
@@ -234,15 +244,14 @@ static enum nss_status fill_in_hostent(
         l_additional = additional ? strlen(additional) : 0;
         ms = ALIGN(l_canonical+1)+
                 (additional ? ALIGN(l_additional+1) : 0) +
-                sizeof(char*)+
+                sizeof(char*) +
                 (additional ? sizeof(char*) : 0) +
-                (c > 0 ? c : 1)*ALIGN(alen)+
-                (c > 0 ? c+1 : 2)*sizeof(char*);
+                (c > 0 ? c : 1) * ALIGN(alen)+
+                (c > 0 ? c+1 : 2) * sizeof(char*);
 
         if (buflen < ms) {
                 *errnop = ENOMEM;
                 *h_errnop = NO_RECOVERY;
-                free(addresses);
                 return NSS_STATUS_TRYAGAIN;
         }
 
@@ -277,7 +286,7 @@ static enum nss_status fill_in_hostent(
                         if (af != a->family)
                                 continue;
 
-                        memcpy(r_addr + i*ALIGN(alen), a->address, alen);
+                        memcpy(r_addr + i*ALIGN(alen), &a->address, alen);
                         i++;
                 }
 
@@ -330,8 +339,6 @@ static enum nss_status fill_in_hostent(
         if (canonp)
                 *canonp = r_name;
 
-        free(addresses);
-
         return NSS_STATUS_SUCCESS;
 }
 
@@ -344,11 +351,17 @@ enum nss_status _nss_myhostname_gethostbyname3_r(
                 int32_t *ttlp,
                 char **canonp) {
 
-        char hn[HOST_NAME_MAX+1] = {};
-        struct address *addresses = NULL;
-        unsigned n_addresses = 0;
+        _cleanup_free_ struct address *addresses = NULL;
         const char *canonical, *additional = NULL;
+        _cleanup_free_ char *hn = NULL;
         uint32_t local_address_ipv4;
+        unsigned n_addresses = 0;
+
+        assert(name);
+        assert(host);
+        assert(buffer);
+        assert(errnop);
+        assert(h_errnop);
 
         if (af == AF_UNSPEC)
                 af = AF_INET;
@@ -359,17 +372,18 @@ enum nss_status _nss_myhostname_gethostbyname3_r(
                 return NSS_STATUS_UNAVAIL;
         }
 
-        if (strcasecmp(name, "localhost") == 0) {
+        if (is_localhost(name)) {
                 canonical = "localhost";
                 local_address_ipv4 = htonl(INADDR_LOOPBACK);
         } else {
-                if (gethostname(hn, sizeof(hn)-1) < 0) {
-                        *errnop = errno;
+                hn = gethostname_malloc();
+                if (!hn) {
+                        *errnop = ENOMEM;
                         *h_errnop = NO_RECOVERY;
-                        return NSS_STATUS_UNAVAIL;
+                        return NSS_STATUS_TRYAGAIN;
                 }
 
-                if (strcasecmp(name, hn) != 0) {
+                if (!streq(name, hn) && !streq_ptr(startswith(name, hn), ".")) {
                         *errnop = ENOENT;
                         *h_errnop = HOST_NOT_FOUND;
                         return NSS_STATUS_NOTFOUND;
@@ -435,12 +449,18 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r(
                 int *errnop, int *h_errnop,
                 int32_t *ttlp) {
 
-        char hn[HOST_NAME_MAX+1] = {};
-        struct address *addresses = NULL;
-        struct address *a;
-        unsigned n_addresses = 0, n;
-        uint32_t local_address_ipv4 = LOCALADDRESS_IPV4;
         const char *canonical = NULL, *additional = NULL;
+        uint32_t local_address_ipv4 = LOCALADDRESS_IPV4;
+        _cleanup_free_ struct address *addresses = NULL;
+        _cleanup_free_ char *hn = NULL;
+        unsigned n_addresses = 0, n;
+        struct address *a;
+
+        assert(addr);
+        assert(host);
+        assert(buffer);
+        assert(errnop);
+        assert(h_errnop);
 
         if (len != PROTO_ADDRESS_SIZE(af)) {
                 *errnop = EINVAL;
@@ -478,26 +498,22 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r(
                 if (af != a->family)
                         continue;
 
-                if (memcmp(addr, a->address, PROTO_ADDRESS_SIZE(af)) == 0)
+                if (memcmp(addr, &a->address, PROTO_ADDRESS_SIZE(af)) == 0)
                         goto found;
         }
 
         *errnop = ENOENT;
         *h_errnop = HOST_NOT_FOUND;
 
-        free(addresses);
-
         return NSS_STATUS_NOTFOUND;
 
 found:
         if (!canonical) {
-                if (gethostname(hn, sizeof(hn)-1) < 0) {
-                        *errnop = errno;
+                hn = gethostname_malloc();
+                if (!hn) {
+                        *errnop = ENOMEM;
                         *h_errnop = NO_RECOVERY;
-
-                        free(addresses);
-
-                        return NSS_STATUS_UNAVAIL;
+                        return NSS_STATUS_TRYAGAIN;
                 }
 
                 canonical = hn;