diff --git a/TODO b/TODO index 9a23ab5eb6..88a3b2cb45 100644 --- a/TODO +++ b/TODO @@ -26,6 +26,10 @@ Fedora 19: Features: +* nss-myhostname: investigate whether there's any point in also + resolving localhost6, localhost.localdomain, ip6-localhost or any of + the other names often seen in /etc/hosts + * see if we can fix https://bugs.freedesktop.org/show_bug.cgi?id=63672 without dropping the location cache entirely. @@ -47,14 +51,10 @@ Features: * timedatctl, localectl: possibly make some commands work without the daemon, for chroot situations... -* logind: consider making suspend inhibitor locks non-session specific, but keep suspend-key inhibitor locks session specific - * logind: add Suspend() bus calls which take timestamps to fix double suspend issues when somebody hits suspend and closes laptop quickly. * we need dynamic units -* nss-myhostname should also resolve 'localhost' so that /etc/hosts becomes optional. - * add s.th. like "systemctl set-log-level debug" * sd-login: allow enumerating machines and add inotify iface diff --git a/src/nss-myhostname/nss-myhostname.c b/src/nss-myhostname/nss-myhostname.c index 8699098b54..60e256d54f 100644 --- a/src/nss-myhostname/nss-myhostname.c +++ b/src/nss-myhostname/nss-myhostname.c @@ -32,7 +32,6 @@ #include "ifconf.h" #include "macro.h" -#include "util.h" /* Ensure that glibc's assert is used. We cannot use assert from macro.h, as * libnss_myhostname will be linked into arbitrary programs which will, in turn @@ -101,31 +100,46 @@ enum nss_status _nss_myhostname_gethostbyname4_r( 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; unsigned n_addresses = 0, n; + uint32_t local_address_ipv4; - if (gethostname(hn, sizeof(hn)-1) < 0) { - *errnop = errno; - *h_errnop = NO_RECOVERY; - return NSS_STATUS_UNAVAIL; + if (strcasecmp(name, "localhost") == 0) { + /* 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; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + } + + if (strcasecmp(name, hn) != 0) { + *errnop = ENOENT; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + /* If this fails, n_addresses is 0. Which is fine */ + ifconf_acquire_addresses(&addresses, &n_addresses); + + canonical = hn; + local_address_ipv4 = LOCALADDRESS_IPV4; } - if (strcasecmp(name, hn) != 0) { - *errnop = ENOENT; - *h_errnop = HOST_NOT_FOUND; - return NSS_STATUS_NOTFOUND; - } - - /* If this fails, n_addresses is 0. Which is fine */ - ifconf_acquire_addresses(&addresses, &n_addresses); - /* If this call fails we fill in 0 as scope. Which is fine */ - lo_ifi = if_nametoindex(LOOPBACK_INTERFACE); + lo_ifi = n_addresses <= 0 ? if_nametoindex(LOOPBACK_INTERFACE) : 0; - l = strlen(hn); + l = strlen(canonical); ms = ALIGN(l+1)+ALIGN(sizeof(struct gaih_addrtuple))*(n_addresses > 0 ? n_addresses : 2); if (buflen < ms) { *errnop = ENOMEM; @@ -136,7 +150,7 @@ enum nss_status _nss_myhostname_gethostbyname4_r( /* First, fill in hostname */ r_name = buffer; - memcpy(r_name, hn, l+1); + memcpy(r_name, canonical, l+1); idx = ALIGN(l+1); if (n_addresses <= 0) { @@ -156,7 +170,7 @@ enum nss_status _nss_myhostname_gethostbyname4_r( r_tuple->next = r_tuple_prev; r_tuple->name = r_name; r_tuple->family = AF_INET; - *(uint32_t*) r_tuple->addr = LOCALADDRESS_IPV4; + *(uint32_t*) r_tuple->addr = local_address_ipv4; r_tuple->scopeid = (uint32_t) lo_ifi; idx += ALIGN(sizeof(struct gaih_addrtuple)); @@ -194,31 +208,34 @@ enum nss_status _nss_myhostname_gethostbyname4_r( } static enum nss_status fill_in_hostent( - const char *hn, + const char *canonical, const char *additional, int af, + struct address *addresses, unsigned n_addresses, + uint32_t local_address_ipv4, struct hostent *result, char *buffer, size_t buflen, int *errnop, int *h_errnop, int32_t *ttlp, char **canonp) { - size_t l, idx, ms; - char *r_addr, *r_name, *r_aliases, *r_addr_list; + size_t l_canonical, l_additional, idx, ms; + char *r_addr, *r_name, *r_aliases, *r_alias = NULL, *r_addr_list; size_t alen; - struct address *addresses = NULL, *a; - unsigned n_addresses = 0, n, c; + struct address *a; + unsigned n, c; alen = PROTO_ADDRESS_SIZE(af); - ifconf_acquire_addresses(&addresses, &n_addresses); - for (a = addresses, n = 0, c = 0; n < n_addresses; a++, n++) if (af == a->family) c++; - l = strlen(hn); - ms = ALIGN(l+1)+ + l_canonical = strlen(canonical); + l_additional = additional ? strlen(additional) : 0; + ms = ALIGN(l_canonical+1)+ + (additional ? ALIGN(l_additional+1) : 0) + sizeof(char*)+ + (additional ? sizeof(char*) : 0) + (c > 0 ? c : 1)*ALIGN(alen)+ (c > 0 ? c+1 : 2)*sizeof(char*); @@ -229,15 +246,27 @@ static enum nss_status fill_in_hostent( return NSS_STATUS_TRYAGAIN; } - /* First, fill in hostname */ + /* First, fill in hostnames */ r_name = buffer; - memcpy(r_name, hn, l+1); - idx = ALIGN(l+1); + memcpy(r_name, canonical, l_canonical+1); + idx = ALIGN(l_canonical+1); - /* Second, create (empty) aliases array */ + if (additional) { + r_alias = buffer + idx; + memcpy(r_alias, additional, l_additional+1); + idx += ALIGN(l_additional+1); + } + + /* Second, create aliases array */ r_aliases = buffer + idx; - *(char**) r_aliases = NULL; - idx += sizeof(char*); + if (additional) { + ((char**) r_aliases)[0] = r_alias; + ((char**) r_aliases)[1] = NULL; + idx += 2*sizeof(char*); + } else { + ((char**) r_aliases)[0] = NULL; + idx += sizeof(char*); + } /* Third, add addresses */ r_addr = buffer + idx; @@ -256,7 +285,7 @@ static enum nss_status fill_in_hostent( idx += c*ALIGN(alen); } else { if (af == AF_INET) - *(uint32_t*) r_addr = LOCALADDRESS_IPV4; + *(uint32_t*) r_addr = local_address_ipv4; else memcpy(r_addr, LOCALADDRESS_IPV6, 16); @@ -316,6 +345,10 @@ enum nss_status _nss_myhostname_gethostbyname3_r( char **canonp) { char hn[HOST_NAME_MAX+1] = {}; + struct address *addresses = NULL; + unsigned n_addresses = 0; + const char *canonical, *additional = NULL; + uint32_t local_address_ipv4; if (af == AF_UNSPEC) af = AF_INET; @@ -326,19 +359,39 @@ enum nss_status _nss_myhostname_gethostbyname3_r( return NSS_STATUS_UNAVAIL; } - if (gethostname(hn, sizeof(hn)-1) < 0) { - *errnop = errno; - *h_errnop = NO_RECOVERY; - return NSS_STATUS_UNAVAIL; + if (strcasecmp(name, "localhost") == 0) { + canonical = "localhost"; + local_address_ipv4 = htonl(INADDR_LOOPBACK); + } else { + if (gethostname(hn, sizeof(hn)-1) < 0) { + *errnop = errno; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + } + + if (strcasecmp(name, hn) != 0) { + *errnop = ENOENT; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + ifconf_acquire_addresses(&addresses, &n_addresses); + + canonical = hn; + additional = n_addresses <= 0 && af == AF_INET6 ? "localhost" : NULL; + local_address_ipv4 = LOCALADDRESS_IPV4; } - if (strcasecmp(name, hn) != 0) { - *errnop = ENOENT; - *h_errnop = HOST_NOT_FOUND; - return NSS_STATUS_NOTFOUND; - } - - return fill_in_hostent(hn, af, host, buffer, buflen, errnop, h_errnop, ttlp, canonp); + return fill_in_hostent( + canonical, additional, + af, + addresses, n_addresses, + local_address_ipv4, + host, + buffer, buflen, + errnop, h_errnop, + ttlp, + canonp); } enum nss_status _nss_myhostname_gethostbyname2_r( @@ -383,9 +436,11 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r( int32_t *ttlp) { char hn[HOST_NAME_MAX+1] = {}; - _cleanup_free_ struct address *addresses = NULL; + 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; if (len != PROTO_ADDRESS_SIZE(af)) { *errnop = EINVAL; @@ -398,10 +453,18 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r( if ((*(uint32_t*) addr) == LOCALADDRESS_IPV4) goto found; + if ((*(uint32_t*) addr) == htonl(INADDR_LOOPBACK)) { + canonical = "localhost"; + local_address_ipv4 = htonl(INADDR_LOOPBACK); + goto found; + } + } else if (af == AF_INET6) { - if (memcmp(addr, LOCALADDRESS_IPV6, 16) == 0) + if (memcmp(addr, LOCALADDRESS_IPV6, 16) == 0) { + additional = "localhost"; goto found; + } } else { *errnop = EAFNOSUPPORT; @@ -422,17 +485,34 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r( *errnop = ENOENT; *h_errnop = HOST_NOT_FOUND; + free(addresses); + return NSS_STATUS_NOTFOUND; found: - if (gethostname(hn, sizeof(hn)-1) < 0) { - *errnop = errno; - *h_errnop = NO_RECOVERY; + if (!canonical) { + if (gethostname(hn, sizeof(hn)-1) < 0) { + *errnop = errno; + *h_errnop = NO_RECOVERY; - return NSS_STATUS_UNAVAIL; + free(addresses); + + return NSS_STATUS_UNAVAIL; + } + + canonical = hn; } - return fill_in_hostent(hn, af, host, buffer, buflen, errnop, h_errnop, ttlp, NULL); + return fill_in_hostent( + canonical, additional, + af, + addresses, n_addresses, + local_address_ipv4, + host, + buffer, buflen, + errnop, h_errnop, + ttlp, + NULL); }