X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fnss-myhostname%2Fnss-myhostname.c;h=4a5bf759a9a2ae6921e13c5997d8fe61ed64abb2;hp=8699098b5478407c3a7d3a07d9773a413f5e6e58;hb=d2df88ffbac8858214adb9daaf7a93122fe26a50;hpb=1e335af70f29d1a1e9c132338aa35b8971934441 diff --git a/src/nss-myhostname/nss-myhostname.c b/src/nss-myhostname/nss-myhostname.c index 8699098b5..4a5bf759a 100644 --- a/src/nss-myhostname/nss-myhostname.c +++ b/src/nss-myhostname/nss-myhostname.c @@ -30,15 +30,11 @@ #include #include -#include "ifconf.h" +#include "local-addresses.h" #include "macro.h" +#include "nss-util.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 - * attempt to write to the journal via log_dispatch() */ -#include - /* We use 127.0.0.2 as IPv4 address. This has the advantage over * 127.0.0.1 that it can be translated back to the local hostname. For * IPv6 we use ::1 which unfortunately will not translate back to the @@ -48,95 +44,88 @@ #define LOCALADDRESS_IPV6 &in6addr_loopback #define LOOPBACK_INTERFACE "lo" +NSS_GETHOSTBYNAME_PROTOTYPES(myhostname); +NSS_GETHOSTBYADDR_PROTOTYPES(myhostname); + enum nss_status _nss_myhostname_gethostbyname4_r( const char *name, struct gaih_addrtuple **pat, char *buffer, size_t buflen, int *errnop, int *h_errnop, - int32_t *ttlp) _public_; + int32_t *ttlp) { -enum nss_status _nss_myhostname_gethostbyname3_r( - const char *name, - int af, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop, - int32_t *ttlp, - char **canonp) _public_; + struct gaih_addrtuple *r_tuple, *r_tuple_prev = NULL; + _cleanup_free_ struct local_address *addresses = NULL; + _cleanup_free_ char *hn = NULL; + const char *canonical = NULL; + int n_addresses = 0, lo_ifi; + uint32_t local_address_ipv4; + struct local_address *a; + size_t l, idx, ms; + char *r_name; + unsigned n; -enum nss_status _nss_myhostname_gethostbyname2_r( - const char *name, - int af, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop) _public_; + assert(name); + assert(pat); + assert(buffer); + assert(errnop); + assert(h_errnop); -enum nss_status _nss_myhostname_gethostbyname_r( - const char *name, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop) _public_; + if (is_localhost(name)) { + /* We respond to 'localhost', so that /etc/hosts + * is optional */ -enum nss_status _nss_myhostname_gethostbyaddr2_r( - const void* addr, socklen_t len, - int af, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop, - int32_t *ttlp) _public_; + canonical = "localhost"; + local_address_ipv4 = htonl(INADDR_LOOPBACK); -enum nss_status _nss_myhostname_gethostbyaddr_r( - const void* addr, socklen_t len, - int af, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop) _public_; + } else if (streq(name, "gateway")) { -enum nss_status _nss_myhostname_gethostbyname4_r( - const char *name, - struct gaih_addrtuple **pat, - char *buffer, size_t buflen, - int *errnop, int *h_errnop, - int32_t *ttlp) { + n_addresses = local_gateways(NULL, 0, &addresses); + if (n_addresses <= 0) { + *errnop = ENOENT; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } - unsigned lo_ifi; - char hn[HOST_NAME_MAX+1] = {}; - 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; + canonical = "gateway"; - if (gethostname(hn, sizeof(hn)-1) < 0) { - *errnop = errno; - *h_errnop = NO_RECOVERY; - return NSS_STATUS_UNAVAIL; - } + } else { + hn = gethostname_malloc(); + if (!hn) { + *errnop = ENOMEM; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_TRYAGAIN; + } - if (strcasecmp(name, hn) != 0) { - *errnop = ENOENT; - *h_errnop = HOST_NOT_FOUND; - return NSS_STATUS_NOTFOUND; - } + /* 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; + } - /* If this fails, n_addresses is 0. Which is fine */ - ifconf_acquire_addresses(&addresses, &n_addresses); + n_addresses = local_addresses(NULL, 0, &addresses); + if (n_addresses < 0) + n_addresses = 0; + + canonical = hn; + local_address_ipv4 = LOCALADDRESS_IPV4; + } /* 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); - ms = ALIGN(l+1)+ALIGN(sizeof(struct gaih_addrtuple))*(n_addresses > 0 ? n_addresses : 2); + l = strlen(canonical); + 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; } /* 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 +145,7 @@ 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)); @@ -164,13 +153,13 @@ enum nss_status _nss_myhostname_gethostbyname4_r( } /* Fourth, fill actual addresses in, but in backwards order */ - for (a = addresses + n_addresses - 1, n = 0; n < n_addresses; n++, a--) { + for (a = addresses + n_addresses - 1, n = 0; (int) n < n_addresses; n++, a--) { r_tuple = (struct gaih_addrtuple*) (buffer + idx); r_tuple->next = r_tuple_prev; 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; @@ -188,56 +177,78 @@ enum nss_status _nss_myhostname_gethostbyname4_r( if (ttlp) *ttlp = 0; - free(addresses); + /* Explicitly reset all error variables */ + *errnop = 0; + *h_errnop = NETDB_SUCCESS; + h_errno = 0; return NSS_STATUS_SUCCESS; } static enum nss_status fill_in_hostent( - const char *hn, + const char *canonical, const char *additional, int af, + struct local_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 alen; - struct address *addresses = NULL, *a; - unsigned n_addresses = 0, n, c; + size_t l_canonical, l_additional, idx, ms, alen; + char *r_addr, *r_name, *r_aliases, *r_alias = NULL, *r_addr_list; + struct local_address *a; + unsigned n, c; - alen = PROTO_ADDRESS_SIZE(af); + assert(canonical); + assert(result); + assert(buffer); + assert(errnop); + assert(h_errnop); - ifconf_acquire_addresses(&addresses, &n_addresses); + alen = FAMILY_ADDRESS_SIZE(af); for (a = addresses, n = 0, c = 0; n < n_addresses; a++, n++) if (af == a->family) c++; - l = strlen(hn); - ms = ALIGN(l+1)+ - sizeof(char*)+ - (c > 0 ? c : 1)*ALIGN(alen)+ - (c > 0 ? c+1 : 2)*sizeof(char*); + 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*); if (buflen < ms) { *errnop = ENOMEM; *h_errnop = NO_RECOVERY; - free(addresses); 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; @@ -248,7 +259,7 @@ 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++; } @@ -256,7 +267,7 @@ 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); @@ -266,24 +277,18 @@ static enum nss_status fill_in_hostent( /* Fourth, add address pointer array */ r_addr_list = buffer + idx; if (c > 0) { - unsigned i = 0; + unsigned i; - for (a = addresses, n = 0; n < n_addresses; a++, n++) { - if (af != a->family) - continue; - - ((char**) r_addr_list)[i] = (r_addr + i*ALIGN(alen)); - i++; - } + for (i = 0; i < c; i++) + ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen); - assert(i == c); - ((char**) r_addr_list)[c] = NULL; - idx += (c+1)*sizeof(char*); + ((char**) r_addr_list)[i] = NULL; + idx += (c+1) * sizeof(char*); } else { ((char**) r_addr_list)[0] = r_addr; ((char**) r_addr_list)[1] = NULL; - idx += 2*sizeof(char*); + idx += 2 * sizeof(char*); } /* Verify the size matches */ @@ -301,7 +306,10 @@ static enum nss_status fill_in_hostent( if (canonp) *canonp = r_name; - free(addresses); + /* Explicitly reset all error variables */ + *errnop = 0; + *h_errnop = NETDB_SUCCESS; + h_errno = 0; return NSS_STATUS_SUCCESS; } @@ -315,7 +323,17 @@ enum nss_status _nss_myhostname_gethostbyname3_r( int32_t *ttlp, char **canonp) { - char hn[HOST_NAME_MAX+1] = {}; + _cleanup_free_ struct local_address *addresses = NULL; + const char *canonical, *additional = NULL; + _cleanup_free_ char *hn = NULL; + uint32_t local_address_ipv4 = 0; + int n_addresses = 0; + + assert(name); + assert(host); + assert(buffer); + assert(errnop); + assert(h_errnop); if (af == AF_UNSPEC) af = AF_INET; @@ -326,52 +344,54 @@ 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 (is_localhost(name)) { + canonical = "localhost"; + local_address_ipv4 = htonl(INADDR_LOOPBACK); - if (strcasecmp(name, hn) != 0) { - *errnop = ENOENT; - *h_errnop = HOST_NOT_FOUND; - return NSS_STATUS_NOTFOUND; - } + } else if (streq(name, "gateway")) { - return fill_in_hostent(hn, af, host, buffer, buflen, errnop, h_errnop, ttlp, canonp); -} + n_addresses = local_gateways(NULL, af, &addresses); + if (n_addresses <= 0) { + *errnop = ENOENT; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } -enum nss_status _nss_myhostname_gethostbyname2_r( - const char *name, - int af, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop) { + canonical = "gateway"; - return _nss_myhostname_gethostbyname3_r( - name, - af, - host, - buffer, buflen, - errnop, h_errnop, - NULL, - NULL); -} + } else { + hn = gethostname_malloc(); + if (!hn) { + *errnop = ENOMEM; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_TRYAGAIN; + } -enum nss_status _nss_myhostname_gethostbyname_r( - const char *name, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop) { + if (!streq(name, hn) && !streq_ptr(startswith(name, hn), ".")) { + *errnop = ENOENT; + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + } + + n_addresses = local_addresses(NULL, af, &addresses); + if (n_addresses < 0) + n_addresses = 0; + + canonical = hn; + additional = n_addresses <= 0 && af == AF_INET6 ? "localhost" : NULL; + local_address_ipv4 = LOCALADDRESS_IPV4; + } - return _nss_myhostname_gethostbyname3_r( - name, - AF_UNSPEC, + return fill_in_hostent( + canonical, additional, + af, + addresses, n_addresses, + local_address_ipv4, host, buffer, buflen, errnop, h_errnop, - NULL, - NULL); + ttlp, + canonp); } enum nss_status _nss_myhostname_gethostbyaddr2_r( @@ -382,12 +402,27 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r( int *errnop, int *h_errnop, int32_t *ttlp) { - char hn[HOST_NAME_MAX+1] = {}; - _cleanup_free_ struct address *addresses = NULL; - struct address *a; - unsigned n_addresses = 0, n; + const char *canonical = NULL, *additional = NULL; + uint32_t local_address_ipv4 = LOCALADDRESS_IPV4; + _cleanup_free_ struct local_address *addresses = NULL; + _cleanup_free_ char *hn = NULL; + int n_addresses = 0; + struct local_address *a; + unsigned n; + + assert(addr); + assert(host); + assert(buffer); + assert(errnop); + assert(h_errnop); + + if (!IN_SET(af, AF_INET, AF_INET6)) { + *errnop = EAFNOSUPPORT; + *h_errnop = NO_DATA; + return NSS_STATUS_UNAVAIL; + } - if (len != PROTO_ADDRESS_SIZE(af)) { + if (len != FAMILY_ADDRESS_SIZE(af)) { *errnop = EINVAL; *h_errnop = NO_RECOVERY; return NSS_STATUS_UNAVAIL; @@ -398,56 +433,79 @@ enum nss_status _nss_myhostname_gethostbyaddr2_r( if ((*(uint32_t*) addr) == LOCALADDRESS_IPV4) goto found; - } else if (af == AF_INET6) { - - if (memcmp(addr, LOCALADDRESS_IPV6, 16) == 0) + if ((*(uint32_t*) addr) == htonl(INADDR_LOOPBACK)) { + canonical = "localhost"; + local_address_ipv4 = htonl(INADDR_LOOPBACK); goto found; + } } else { - *errnop = EAFNOSUPPORT; - *h_errnop = NO_DATA; - return NSS_STATUS_UNAVAIL; + assert(af == AF_INET6); + + if (memcmp(addr, LOCALADDRESS_IPV6, 16) == 0) { + additional = "localhost"; + goto found; + } + } - ifconf_acquire_addresses(&addresses, &n_addresses); + n_addresses = local_addresses(NULL, 0, &addresses); + if (n_addresses > 0) { + for (a = addresses, n = 0; (int) n < n_addresses; n++, a++) { + if (af != a->family) + continue; - for (a = addresses, n = 0; n < n_addresses; n++, a++) { - if (af != a->family) - continue; + if (memcmp(addr, &a->address, FAMILY_ADDRESS_SIZE(af)) == 0) { - if (memcmp(addr, a->address, PROTO_ADDRESS_SIZE(af)) == 0) - goto found; + hn = gethostname_malloc(); + if (!hn) { + *errnop = ENOMEM; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_TRYAGAIN; + } + + canonical = hn; + goto found; + } + } } - *errnop = ENOENT; - *h_errnop = HOST_NOT_FOUND; + free(addresses); + addresses = NULL; - return NSS_STATUS_NOTFOUND; + n_addresses = local_gateways(NULL, 0, &addresses); + if (n_addresses > 0) { + for (a = addresses, n = 0; (int) n < n_addresses; n++, a++) { + if (af != a->family) + continue; -found: - if (gethostname(hn, sizeof(hn)-1) < 0) { - *errnop = errno; - *h_errnop = NO_RECOVERY; + if (memcmp(addr, &a->address, FAMILY_ADDRESS_SIZE(af)) == 0) { - return NSS_STATUS_UNAVAIL; + canonical = "gateway"; + goto found; + } + } } - return fill_in_hostent(hn, af, host, buffer, buflen, errnop, h_errnop, ttlp, NULL); + *errnop = ENOENT; + *h_errnop = HOST_NOT_FOUND; -} + return NSS_STATUS_NOTFOUND; -enum nss_status _nss_myhostname_gethostbyaddr_r( - const void* addr, socklen_t len, - int af, - struct hostent *host, - char *buffer, size_t buflen, - int *errnop, int *h_errnop) { +found: - return _nss_myhostname_gethostbyaddr2_r( - addr, len, + return fill_in_hostent( + canonical, additional, af, + addresses, n_addresses, + local_address_ipv4, host, buffer, buflen, errnop, h_errnop, + ttlp, NULL); + } + +NSS_GETHOSTBYNAME_FALLBACKS(myhostname); +NSS_GETHOSTBYADDR_FALLBACKS(myhostname);