diff options
| -rw-r--r-- | libc/inet/resolv.c | 416 |
1 files changed, 197 insertions, 219 deletions
diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c index e377c3883..c6807aae1 100644 --- a/libc/inet/resolv.c +++ b/libc/inet/resolv.c @@ -151,6 +151,7 @@ #include <netdb.h> #include <ctype.h> #include <stdbool.h> +#include <time.h> #include <arpa/nameser.h> #include <sys/utsname.h> #include <sys/un.h> @@ -219,6 +220,13 @@ /* libc_hidden_proto(__ctype_b) */ #endif +#if defined __UCLIBC_HAS_IPV4__ && defined __UCLIBC_HAS_IPV6__ +#define IF_HAS_BOTH(...) __VA_ARGS__ +#else +#define IF_HAS_BOTH(...) +#endif + + extern int __libc_getdomainname(char *name, size_t len); libc_hidden_proto(__libc_getdomainname) @@ -919,13 +927,22 @@ static char *skip_and_NUL_space(char *p) /* Must be called under __resolv_lock. */ void attribute_hidden __open_nameservers(void) { + static uint8_t last_time; + char szBuffer[MAXLEN_searchdomain]; FILE *fp; int i; sockaddr46_t sa; - //if (!__res_sync && last_time_was_long_ago) - // __close_nameservers(); /* force config reread */ + if (!__res_sync) { + /* Provide for periodic reread of /etc/resolv.conf */ + /* cur_time "ticks" every 256 seconds */ + uint8_t cur_time = ((unsigned)time(NULL)) >> 8; + if (last_time != cur_time) { + last_time = cur_time; + __close_nameservers(); /* force config reread */ + } + } if (__nameservers) goto sync; @@ -1290,14 +1307,18 @@ int attribute_hidden __dns_lookup(const char *name, int type, h_errno = HOST_NOT_FOUND; goto fail1; } - if (h.rcode != 0) /* error */ - goto try_next_sdomain; - /* code below won't work correctly with h.ancount == 0, so... */ + /* Insert other non-fatal errors here, which do not warrant + * switching to next nameserver */ + + /* Strange error, assuming this nameserver is feeling bad */ + if (h.rcode != 0) + goto try_next_server; + + /* Code below won't work correctly with h.ancount == 0, so... */ if (h.ancount <= 0) { h_errno = NO_DATA; /* is this correct code? */ goto fail1; } - pos = HFIXEDSZ; for (j = 0; j < h.qdcount; j++) { DPRINTF("Skipping question %d at %d\n", j, pos); @@ -1313,11 +1334,11 @@ int attribute_hidden __dns_lookup(const char *name, int type, i = __decode_answer(packet, pos, len, &ma); if (i < 0) { DPRINTF("failed decode %d\n", i); - /* if the message was truncated and we have + /* If the message was truncated but we have * decoded some answers, pretend it's OK */ if (j && h.tc) break; - goto try_next_sdomain; + goto try_next_server; } pos += i; @@ -1345,14 +1366,14 @@ int attribute_hidden __dns_lookup(const char *name, int type, free(a->dotted); DPRINTF("Answer address len(%u) differs from original(%u)\n", ma.rdlength, a->rdlength); - goto try_next_sdomain; + goto try_next_server; } memcpy(a->buf + (a->add_count * ma.rdlength), ma.rdata, ma.rdlength); ++a->add_count; } } - /* success! */ + /* Success! */ DPRINTF("Answer name = |%s|\n", a->dotted); DPRINTF("Answer type = |%d|\n", a->atype); if (fd != -1) @@ -1364,20 +1385,8 @@ int attribute_hidden __dns_lookup(const char *name, int type, free(lookup); return len; -//TODO: audit whether *any* "goto try_next_sdomain" is actually correct: -//trying next search domain makes sense only if we got NXDOMAIN! -//why we do it in other cases too? - try_next_sdomain: - /* if there are searchdomains, try them */ - if (!ends_with_dot) { - if (variant < sdomains - 1) { - /* next search */ - variant++; - continue; - } - } try_next_server: - /* if there are other nameservers, try them */ + /* Try next nameserver */ local_ns_num++; variant = -1; } while (retries_left > 0); @@ -1415,53 +1424,40 @@ int attribute_hidden __read_etc_hosts_r( struct hostent ** result, int * h_errnop) { - struct in_addr *in = NULL; struct in_addr **addr_list = NULL; -#ifdef __UCLIBC_HAS_IPV6__ - struct in6_addr *in6 = NULL; - struct in6_addr **addr_list6 = NULL; -#endif /* __UCLIBC_HAS_IPV6__ */ + struct in_addr *in = NULL; char *cp, **alias; int aliases, i, ret = HOST_NOT_FOUND; - /* make sure user char * is aligned */ + *h_errnop = NETDB_INTERNAL; + + /* make sure pointer is aligned */ i = ALIGN_BUFFER_OFFSET(buf); buf += i; buflen -= i; - + /* Layout in buf: + * char *alias[ALIAS_DIM]; + * struct in[6]_addr* addr_list[2]; + * struct in[6]_addr* in; + * char line_buffer[80+]; + */ +#define in6 ((struct in6_addr *)in) alias = (char **)buf; buf += sizeof(char **) * ALIAS_DIM; buflen -= sizeof(char **) * ALIAS_DIM; if ((ssize_t)buflen < 0) return ERANGE; - if (action != GETHOSTENT) { -#ifdef __UCLIBC_HAS_IPV6__ - char *p = buf; - size_t len = buflen; -#endif - *h_errnop = NETDB_INTERNAL; + addr_list = (struct in_addr**)buf; + buf += sizeof(*addr_list) * 2; + buflen -= sizeof(*addr_list) * 2; in = (struct in_addr*)buf; +#ifndef __UCLIBC_HAS_IPV6__ buf += sizeof(*in); buflen -= sizeof(*in); - addr_list = (struct in_addr **)buf; - buf += sizeof(*addr_list) * 2; - buflen -= sizeof(*addr_list) * 2; - if ((ssize_t)buflen < 0) - return ERANGE; -#ifdef __UCLIBC_HAS_IPV6__ - in6 = (struct in6_addr*)p; - p += sizeof(*in6); - len -= sizeof(*in6); - addr_list6 = (struct in6_addr**)p; - p += sizeof(*addr_list6) * 2; - len -= sizeof(*addr_list6) * 2; - if ((ssize_t)len < 0) - return ERANGE; - if (len < buflen) { - buflen = len; - buf = p; - } +#else + buf += sizeof(*in6); + buflen -= sizeof(*in6); #endif if ((ssize_t)buflen < 80) return ERANGE; @@ -1472,12 +1468,12 @@ int attribute_hidden __read_etc_hosts_r( return errno; } } + addr_list[0] = in; + addr_list[1] = NULL; *h_errnop = HOST_NOT_FOUND; while (fgets(buf, buflen, fp)) { - cp = strchr(buf, '#'); - if (cp) - *cp = '\0'; + *strchrnul(buf, '#') = '\0'; DPRINTF("Looking at: %s\n", buf); aliases = 0; @@ -1487,7 +1483,7 @@ int attribute_hidden __read_etc_hosts_r( *cp++ = '\0'; if (!*cp) break; - if (aliases < (2+MAX_ALIASES)) + if (aliases < (2 + MAX_ALIASES)) alias[aliases++] = cp; while (*cp && !isspace(*cp)) cp++; @@ -1508,32 +1504,31 @@ int attribute_hidden __read_etc_hosts_r( /* GET_HOSTS_BYNAME */ for (i = 1; i < aliases; i++) if (strcasecmp(name, alias[i]) == 0) - break; - if (i >= aliases) - continue; + goto found; + continue; + found: ; } - if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) { + if (0) /* nothing */; +#ifdef __UCLIBC_HAS_IPV4__ + else if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) { DPRINTF("Found INET\n"); - addr_list[0] = in; - addr_list[1] = NULL; - result_buf->h_name = alias[1]; result_buf->h_addrtype = AF_INET; result_buf->h_length = sizeof(*in); + result_buf->h_name = alias[1]; result_buf->h_addr_list = (char**) addr_list; result_buf->h_aliases = alias + 2; *result = result_buf; ret = NETDB_SUCCESS; } +#endif #ifdef __UCLIBC_HAS_IPV6__ else if (type == AF_INET6 && inet_pton(AF_INET6, alias[0], in6) > 0) { DPRINTF("Found INET6\n"); - addr_list6[0] = in6; - addr_list6[1] = NULL; - result_buf->h_name = alias[1]; result_buf->h_addrtype = AF_INET6; result_buf->h_length = sizeof(*in6); - result_buf->h_addr_list = (char**) addr_list6; + result_buf->h_name = alias[1]; + result_buf->h_addr_list = (char**) addr_list; result_buf->h_aliases = alias + 2; *result = result_buf; ret = NETDB_SUCCESS; @@ -1557,6 +1552,7 @@ int attribute_hidden __read_etc_hosts_r( if (action != GETHOSTENT) fclose(fp); return ret; +#undef in6 } #endif @@ -1587,19 +1583,21 @@ int attribute_hidden __get_hosts_byaddr_r(const char * addr, int len, int type, char ipaddr[INET_ADDRSTRLEN]; #else char ipaddr[INET6_ADDRSTRLEN]; -#endif /* __UCLIBC_HAS_IPV6__ */ +#endif switch (type) { +#ifdef __UCLIBC_HAS_IPV4__ case AF_INET: if (len != sizeof(struct in_addr)) return 0; break; +#endif #ifdef __UCLIBC_HAS_IPV6__ case AF_INET6: if (len != sizeof(struct in6_addr)) return 0; break; -#endif /* __UCLIBC_HAS_IPV6__ */ +#endif default: return 0; } @@ -1627,24 +1625,23 @@ int getnameinfo(const struct sockaddr *sa, socklen_t addrlen, char *host, return EAI_BADFLAGS; if (sa == NULL || addrlen < sizeof(sa_family_t)) - goto BAD_FAM; + return EAI_FAMILY; ok = sa->sa_family; if (ok == AF_LOCAL) /* valid */; #ifdef __UCLIBC_HAS_IPV4__ else if (ok == AF_INET) { if (addrlen < sizeof(struct sockaddr_in)) - goto BAD_FAM; + return EAI_FAMILY; } #endif #ifdef __UCLIBC_HAS_IPV6__ else if (ok == AF_INET6) { if (addrlen < sizeof(struct sockaddr_in6)) - goto BAD_FAM; + return EAI_FAMILY; } -#endif /* __UCLIBC_HAS_IPV6__ */ +#endif else -BAD_FAM: return EAI_FAMILY; ok = 0; @@ -1813,6 +1810,8 @@ libc_hidden_def(getnameinfo) #ifdef L_gethostbyname_r +//Does this function assume IPv4? If yes, +//what happens in IPv6-only build? /* Bug 671 says: * "uClibc resolver's gethostbyname does not return the requested name @@ -1892,23 +1891,23 @@ int gethostbyname_r(const char * name, i = strlen(name) + 1; if ((ssize_t)buflen <= i) return ERANGE; - strcpy(buf, name); + memcpy(buf, name, i); /* paranoia: name might change */ alias0 = buf; buf += i; buflen -= i; - /* make sure pointer is aligned */ i = ALIGN_BUFFER_OFFSET(buf); buf += i; buflen -= i; - + /* Layout in buf: + * char *alias[2]; + * struct in_addr* addr_list[NN+1]; + * struct in_addr* in[NN]; + */ alias = (char **)buf; buf += sizeof(alias[0]) * 2; buflen -= sizeof(alias[0]) * 2; - addr_list = (struct in_addr **)buf; - - /* do not use *buf or buflen before this verification! */ /* buflen may be < 0, must do signed compare */ if ((ssize_t)buflen < 256) return ERANGE; @@ -1946,18 +1945,16 @@ int gethostbyname_r(const char * name, } /* talk to DNS servers */ - { - a.buf = buf; - /* take into account that at least one address will be there, - * we'll need space of one in_addr + two addr_list[] elems */ - a.buflen = buflen - ((sizeof(addr_list[0]) * 2 + sizeof(struct in_addr))); - a.add_count = 0; - i = __dns_lookup(name, T_A, &packet, &a); - if (i < 0) { - *h_errnop = HOST_NOT_FOUND; - DPRINTF("__dns_lookup returned < 0\n"); - return TRY_AGAIN; - } + a.buf = buf; + /* take into account that at least one address will be there, + * we'll need space of one in_addr + two addr_list[] elems */ + a.buflen = buflen - ((sizeof(addr_list[0]) * 2 + sizeof(struct in_addr))); + a.add_count = 0; + i = __dns_lookup(name, T_A, &packet, &a); + if (i < 0) { + *h_errnop = HOST_NOT_FOUND; + DPRINTF("__dns_lookup returned < 0\n"); + return TRY_AGAIN; } if (a.atype == T_A) { /* ADDRESS */ @@ -2093,7 +2090,11 @@ int gethostbyname2_r(const char *name, i = ALIGN_BUFFER_OFFSET(buf); buf += i; buflen -= i; - + /* Layout in buf: + * struct in6_addr* in; + * struct in6_addr* addr_list[2]; + * char scratch_buf[256]; + */ in = (struct in6_addr*)buf; buf += sizeof(*in); buflen -= sizeof(*in); @@ -2105,6 +2106,7 @@ int gethostbyname2_r(const char *name, addr_list[0] = in; addr_list[1] = NULL; strncpy(buf, name, buflen); + buf[buflen] = '\0'; /* maybe it is already an address? */ if (inet_pton(AF_INET6, name, in)) { @@ -2112,6 +2114,7 @@ int gethostbyname2_r(const char *name, result_buf->h_addrtype = AF_INET6; result_buf->h_length = sizeof(*in); result_buf->h_addr_list = (char **) addr_list; + //result_buf->h_aliases = ??? *result = result_buf; *h_errnop = NETDB_SUCCESS; return NETDB_SUCCESS; @@ -2129,48 +2132,46 @@ int gethostbyname2_r(const char *name, // TODO: why it's so different from gethostbyname_r (IPv4 case)? memset(&a, '\0', sizeof(a)); for (;;) { +// Hmm why we memset(a) to zeros only once? i = __dns_lookup(buf, T_AAAA, &packet, &a); - if (i < 0) { *h_errnop = HOST_NOT_FOUND; return TRY_AGAIN; } - strncpy(buf, a.dotted, buflen); free(a.dotted); - if (a.atype == T_CNAME) { /* CNAME */ - DPRINTF("Got a CNAME in gethostbyname()\n"); - i = __decode_dotted(packet, a.rdoffset, buf, buflen); - free(packet); + if (a.atype != T_CNAME) + break; - if (i < 0) { - *h_errnop = NO_RECOVERY; - return -1; - } - if (++nest > MAX_RECURSE) { - *h_errnop = NO_RECOVERY; - return -1; - } - continue; + DPRINTF("Got a CNAME in gethostbyname()\n"); + if (++nest > MAX_RECURSE) { + *h_errnop = NO_RECOVERY; + return -1; } - if (a.atype == T_AAAA) { /* ADDRESS */ - memcpy(in, a.rdata, sizeof(*in)); - result_buf->h_name = buf; - result_buf->h_addrtype = AF_INET6; - result_buf->h_length = sizeof(*in); - result_buf->h_addr_list = (char **) addr_list; - free(packet); - break; + i = __decode_dotted(packet, a.rdoffset, buf, buflen); + free(packet); + if (i < 0) { + *h_errnop = NO_RECOVERY; + return -1; } + } + if (a.atype == T_AAAA) { /* ADDRESS */ + memcpy(in, a.rdata, sizeof(*in)); + result_buf->h_name = buf; + result_buf->h_addrtype = AF_INET6; + result_buf->h_length = sizeof(*in); + result_buf->h_addr_list = (char **) addr_list; + //result_buf->h_aliases = ??? free(packet); - *h_errnop = HOST_NOT_FOUND; - return TRY_AGAIN; + *result = result_buf; + *h_errnop = NETDB_SUCCESS; + return NETDB_SUCCESS; } + free(packet); + *h_errnop = HOST_NOT_FOUND; + return TRY_AGAIN; - *result = result_buf; - *h_errnop = NETDB_SUCCESS; - return NETDB_SUCCESS; #endif /* __UCLIBC_HAS_IPV6__ */ } libc_hidden_def(gethostbyname2_r) @@ -2179,7 +2180,7 @@ libc_hidden_def(gethostbyname2_r) #ifdef L_gethostbyaddr_r -int gethostbyaddr_r(const void *addr, socklen_t len, int type, +int gethostbyaddr_r(const void *addr, socklen_t addrlen, int type, struct hostent * result_buf, char * buf, size_t buflen, struct hostent ** result, @@ -2188,12 +2189,6 @@ int gethostbyaddr_r(const void *addr, socklen_t len, int type, { struct in_addr *in; struct in_addr **addr_list; -#ifdef __UCLIBC_HAS_IPV6__ - char *qp; - size_t plen; - struct in6_addr *in6; - struct in6_addr **addr_list6; -#endif /* __UCLIBC_HAS_IPV6__ */ char **alias; unsigned char *packet; struct resolv_answer a; @@ -2204,25 +2199,25 @@ int gethostbyaddr_r(const void *addr, socklen_t len, int type, if (!addr) return EINVAL; - memset(&a, '\0', sizeof(a)); - switch (type) { +#ifdef __UCLIBC_HAS_IPV4__ case AF_INET: - if (len != sizeof(struct in_addr)) + if (addrlen != sizeof(struct in_addr)) return EINVAL; break; +#endif #ifdef __UCLIBC_HAS_IPV6__ case AF_INET6: - if (len != sizeof(struct in6_addr)) + if (addrlen != sizeof(struct in6_addr)) return EINVAL; break; -#endif /* __UCLIBC_HAS_IPV6__ */ +#endif default: return EINVAL; } /* do /etc/hosts first */ - i = __get_hosts_byaddr_r(addr, len, type, result_buf, + i = __get_hosts_byaddr_r(addr, addrlen, type, result_buf, buf, buflen, result, h_errnop); if (i == 0) return i; @@ -2240,68 +2235,59 @@ int gethostbyaddr_r(const void *addr, socklen_t len, int type, i = ALIGN_BUFFER_OFFSET(buf); buf += i; buflen -= i; - -#ifdef __UCLIBC_HAS_IPV6__ - qp = buf; - plen = buflen; -#endif - in = (struct in_addr*)buf; - buf += sizeof(*in); - buflen -= sizeof(*in); - addr_list = (struct in_addr**)buf; - buf += sizeof(*addr_list) * 2; - buflen -= sizeof(*addr_list) * 2; + /* Layout in buf: + * char *alias[ALIAS_DIM]; + * struct in[6]_addr* addr_list[2]; + * struct in[6]_addr* in; + * char scratch_buffer[256+]; + */ +#define in6 ((struct in6_addr *)in) alias = (char **)buf; buf += sizeof(*alias) * ALIAS_DIM; buflen -= sizeof(*alias) * ALIAS_DIM; - if ((ssize_t)buflen < 0) - return ERANGE; -#ifdef __UCLIBC_HAS_IPV6__ - in6 = (struct in6_addr*)qp; - qp += sizeof(*in6); - plen -= sizeof(*in6); - addr_list6 = (struct in6_addr**)qp; - qp += sizeof(*addr_list6) * 2; - plen -= sizeof(*addr_list6) * 2; - if ((ssize_t)plen < 0) - return ERANGE; - if (plen < buflen) { - buflen = plen; - buf = qp; - } + addr_list = (struct in_addr**)buf; + buf += sizeof(*addr_list) * 2; + buflen -= sizeof(*addr_list) * 2; + in = (struct in_addr*)buf; +#ifndef __UCLIBC_HAS_IPV6__ + buf += sizeof(*in); + buflen -= sizeof(*in); +#else + buf += sizeof(*in6); + buflen -= sizeof(*in6); #endif - if (buflen < 256) + if ((ssize_t)buflen < 256) return ERANGE; + alias[0] = buf; + alias[1] = NULL; + addr_list[0] = in; + addr_list[1] = NULL; + memcpy(&in, addr, addrlen); - if (type == AF_INET) { - unsigned char *tmp_addr = (unsigned char *)addr; - - memcpy(&in->s_addr, addr, len); - addr_list[0] = in; + if (0) /* nothing */; +#ifdef __UCLIBC_HAS_IPV4__ + else IF_HAS_BOTH(if (type == AF_INET)) { + unsigned char *tp = (unsigned char *)addr; sprintf(buf, "%u.%u.%u.%u.in-addr.arpa", - tmp_addr[3], tmp_addr[2], tmp_addr[1], tmp_addr[0]); + tp[3], tp[2], tp[1], tp[0]); } +#endif #ifdef __UCLIBC_HAS_IPV6__ else { - memcpy(in6->s6_addr, addr, len); - addr_list6[0] = in6; - qp = buf; - for (i = len - 1; i >= 0; i--) { - qp += sprintf(qp, "%x.%x.", - in6->s6_addr[i] & 0xf, - (in6->s6_addr[i] >> 4) & 0xf); - } - strcpy(qp, "ip6.arpa"); + char *dst = buf; + unsigned char *tp = (unsigned char *)addr + addrlen - 1; + do { + dst += sprintf(dst, "%x.%x.", tp[i] & 0xf, tp[i] >> 4); + tp--; + } while (tp >= (unsigned char *)addr); + strcpy(dst, "ip6.arpa"); } #endif - addr_list[1] = NULL; - - alias[0] = buf; - alias[1] = NULL; + memset(&a, '\0', sizeof(a)); for (;;) { +// Hmm why we memset(a) to zeros only once? i = __dns_lookup(buf, T_PTR, &packet, &a); - if (i < 0) { *h_errnop = HOST_NOT_FOUND; return TRY_AGAIN; @@ -2309,48 +2295,40 @@ int gethostbyaddr_r(const void *addr, socklen_t len, int type, strncpy(buf, a.dotted, buflen); free(a.dotted); + if (a.atype != T_CNAME) + break; - if (a.atype == T_CNAME) { /* CNAME */ - DPRINTF("Got a CNAME in gethostbyaddr()\n"); - i = __decode_dotted(packet, a.rdoffset, buf, buflen); - free(packet); - - if (i < 0) { - *h_errnop = NO_RECOVERY; - return -1; - } - if (++nest > MAX_RECURSE) { - *h_errnop = NO_RECOVERY; - return -1; - } - continue; + DPRINTF("Got a CNAME in gethostbyaddr()\n"); + if (++nest > MAX_RECURSE) { + *h_errnop = NO_RECOVERY; + return -1; } - - if (a.atype == T_PTR) { /* ADDRESS */ - i = __decode_dotted(packet, a.rdoffset, buf, buflen); - free(packet); - - result_buf->h_name = buf; - result_buf->h_addrtype = type; - if (type == AF_INET) - result_buf->h_length = sizeof(*in); -#ifdef __UCLIBC_HAS_IPV6__ - else - result_buf->h_length = sizeof(*in6); -#endif - result_buf->h_addr_list = (char **) addr_list; - result_buf->h_aliases = alias; - break; + /* Decode CNAME into buf, feed it to __dns_lookup() again */ + i = __decode_dotted(packet, a.rdoffset, buf, buflen); + free(packet); + if (i < 0) { + *h_errnop = NO_RECOVERY; + return -1; } + } + if (a.atype == T_PTR) { /* ADDRESS */ + i = __decode_dotted(packet, a.rdoffset, buf, buflen); free(packet); - *h_errnop = NO_ADDRESS; - return TRY_AGAIN; + result_buf->h_name = buf; + result_buf->h_addrtype = type; + result_buf->h_length = addrlen; + result_buf->h_addr_list = (char **) addr_list; + result_buf->h_aliases = alias; + *result = result_buf; + *h_errnop = NETDB_SUCCESS; + return NETDB_SUCCESS; } - *result = result_buf; - *h_errnop = NETDB_SUCCESS; - return NETDB_SUCCESS; + free(packet); + *h_errnop = NO_ADDRESS; + return TRY_AGAIN; +#undef in6 } libc_hidden_def(gethostbyaddr_r) #endif @@ -2605,7 +2583,7 @@ int ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) __set_errno(EMSGSIZE); return -1; } - for ((void)NULL; n > 0; n--) { + for (; n > 0; n--) { c = *cp++; if (special(c)) { if (dn + 1 >= eom) { |