#include <unistd.h>
#include <pthread.h>
#include <errno.h>
+#include <resolv.h>
#include "lookup.h"
#include "stdio_impl.h"
#include "syscall.h"
{
char line[512];
size_t l = strlen(name);
- int cnt = 0;
+ int cnt = 0, badfam = 0, have_canon = 0;
unsigned char _buf[1032];
FILE _f, *f = __fopen_rb_ca("/etc/hosts", &_f, _buf, sizeof _buf);
if (!f) switch (errno) {
/* Isolate IP address to parse */
for (p=line; *p && !isspace(*p); p++);
*p++ = 0;
- if (name_from_numeric(buf+cnt, line, family))
+ switch (name_from_numeric(buf+cnt, line, family)) {
+ case 1:
cnt++;
+ break;
+ case 0:
+ continue;
+ default:
+ badfam = EAI_NODATA;
+ break;
+ }
+
+ if (have_canon) continue;
/* Extract first name as canonical name */
for (; *p && isspace(*p); p++);
for (z=p; *z && !isspace(*z); z++);
*z = 0;
- if (is_valid_hostname(p)) memcpy(canon, p, z-p+1);
+ if (is_valid_hostname(p)) {
+ have_canon = 1;
+ memcpy(canon, p, z-p+1);
+ }
}
__fclose_ca(f);
- return cnt;
+ return cnt ? cnt : badfam;
}
struct dpc_ctx {
struct address *addrs;
char *canon;
int cnt;
+ int rrtype;
};
-int __dns_parse(const unsigned char *, int, int (*)(void *, int, const void *, int, const void *), void *);
-int __dn_expand(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
-int __res_mkquery(int, const char *, int, int, const unsigned char *, int, const unsigned char*, unsigned char *, int);
-int __res_msend(int, const unsigned char *const *, const int *, unsigned char *const *, int *, int);
-
#define RR_A 1
#define RR_CNAME 5
#define RR_AAAA 28
+#define ABUF_SIZE 768
+
static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet)
{
char tmp[256];
struct dpc_ctx *ctx = c;
+ if (ctx->cnt >= MAXADDRS) return 0;
switch (rr) {
case RR_A:
+ if (rr != ctx->rrtype) return 0;
if (len != 4) return -1;
ctx->addrs[ctx->cnt].family = AF_INET;
ctx->addrs[ctx->cnt].scopeid = 0;
memcpy(ctx->addrs[ctx->cnt++].addr, data, 4);
break;
case RR_AAAA:
+ if (rr != ctx->rrtype) return 0;
if (len != 16) return -1;
ctx->addrs[ctx->cnt].family = AF_INET6;
ctx->addrs[ctx->cnt].scopeid = 0;
memcpy(ctx->addrs[ctx->cnt++].addr, data, 16);
break;
case RR_CNAME:
- if (__dn_expand(packet, (const unsigned char *)packet + 512,
+ if (__dn_expand(packet, (const unsigned char *)packet + ABUF_SIZE,
data, tmp, sizeof tmp) > 0 && is_valid_hostname(tmp))
strcpy(ctx->canon, tmp);
break;
return 0;
}
-static int name_from_dns(struct address buf[static MAXADDRS], char canon[static 256], const char *name, int family)
+static int name_from_dns(struct address buf[static MAXADDRS], char canon[static 256], const char *name, int family, const struct resolvconf *conf)
{
- unsigned char qbuf[2][280], abuf[2][512];
+ unsigned char qbuf[2][280], abuf[2][ABUF_SIZE];
const unsigned char *qp[2] = { qbuf[0], qbuf[1] };
unsigned char *ap[2] = { abuf[0], abuf[1] };
- int qlens[2], alens[2];
+ int qlens[2], alens[2], qtypes[2];
int i, nq = 0;
struct dpc_ctx ctx = { .addrs = buf, .canon = canon };
-
- if (family != AF_INET6) {
- qlens[nq] = __res_mkquery(0, name, 1, RR_A, 0, 0, 0,
- qbuf[nq], sizeof *qbuf);
- nq++;
- }
- if (family != AF_INET) {
- qlens[nq] = __res_mkquery(0, name, 1, RR_AAAA, 0, 0, 0,
- qbuf[nq], sizeof *qbuf);
- nq++;
+ static const struct { int af; int rr; } afrr[2] = {
+ { .af = AF_INET6, .rr = RR_A },
+ { .af = AF_INET, .rr = RR_AAAA },
+ };
+
+ for (i=0; i<2; i++) {
+ if (family != afrr[i].af) {
+ qlens[nq] = __res_mkquery(0, name, 1, afrr[i].rr,
+ 0, 0, 0, qbuf[nq], sizeof *qbuf);
+ if (qlens[nq] == -1)
+ return 0;
+ qtypes[nq] = afrr[i].rr;
+ qbuf[nq][3] = 0; /* don't need AD flag */
+ /* Ensure query IDs are distinct. */
+ if (nq && qbuf[nq][0] == qbuf[0][0])
+ qbuf[nq][0]++;
+ nq++;
+ }
}
- if (__res_msend(nq, qp, qlens, ap, alens, sizeof *abuf) < 0) return EAI_SYSTEM;
+ if (__res_msend_rc(nq, qp, qlens, ap, alens, sizeof *abuf, conf) < 0)
+ return EAI_SYSTEM;
+
+ for (i=0; i<nq; i++) {
+ if (alens[i] < 4 || (abuf[i][3] & 15) == 2) return EAI_AGAIN;
+ if ((abuf[i][3] & 15) == 3) return 0;
+ if ((abuf[i][3] & 15) != 0) return EAI_FAIL;
+ }
- for (i=0; i<nq; i++)
+ for (i=nq-1; i>=0; i--) {
+ ctx.rrtype = qtypes[i];
__dns_parse(abuf[i], alens[i], dns_parse_callback, &ctx);
+ }
if (ctx.cnt) return ctx.cnt;
- if (alens[0] < 4 || (abuf[0][3] & 15) == 2) return EAI_AGAIN;
- if ((abuf[0][3] & 15) == 0) return EAI_NONAME;
- if ((abuf[0][3] & 15) == 3) return 0;
- return EAI_FAIL;
+ return EAI_NODATA;
}
static int name_from_dns_search(struct address buf[static MAXADDRS], char canon[static 256], const char *name, int family)
for (dots=l=0; name[l]; l++) if (name[l]=='.') dots++;
if (dots >= conf.ndots || name[l-1]=='.') *search = 0;
+ /* Strip final dot for canon, fail if multiple trailing dots. */
+ if (name[l-1]=='.') l--;
+ if (!l || name[l-1]=='.') return EAI_NONAME;
+
/* This can never happen; the caller already checked length. */
if (l >= 256) return EAI_NONAME;
if (z-p < 256 - l - 1) {
memcpy(canon+l+1, p, z-p);
canon[z-p+1+l] = 0;
- int cnt = name_from_dns(buf, canon, canon, family);
+ int cnt = name_from_dns(buf, canon, canon, family, &conf);
if (cnt) return cnt;
}
}
canon[l] = 0;
- return name_from_dns(buf, canon, name, family);
+ return name_from_dns(buf, canon, name, family, &conf);
}
static const struct policy {
/* No further processing is needed if there are fewer than 2
* results or if there are only IPv4 results. */
if (cnt<2 || family==AF_INET) return cnt;
- for (i=0; buf[i].family == AF_INET; i++)
- if (i==cnt) return cnt;
+ for (i=0; i<cnt; i++) if (buf[i].family != AF_INET) break;
+ if (i==cnt) return cnt;
int cs;
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
* excessive runtime and code size cost and dubious benefit.
* So far the label/precedence table cannot be customized. */
for (i=0; i<cnt; i++) {
+ int family = buf[i].family;
int key = 0;
- struct sockaddr_in6 sa, da = {
+ struct sockaddr_in6 sa6 = { 0 }, da6 = {
.sin6_family = AF_INET6,
.sin6_scope_id = buf[i].scopeid,
.sin6_port = 65535
};
- if (buf[i].family == AF_INET6) {
- memcpy(da.sin6_addr.s6_addr, buf[i].addr, 16);
+ struct sockaddr_in sa4 = { 0 }, da4 = {
+ .sin_family = AF_INET,
+ .sin_port = 65535
+ };
+ void *sa, *da;
+ socklen_t salen, dalen;
+ if (family == AF_INET6) {
+ memcpy(da6.sin6_addr.s6_addr, buf[i].addr, 16);
+ da = &da6; dalen = sizeof da6;
+ sa = &sa6; salen = sizeof sa6;
} else {
- memcpy(da.sin6_addr.s6_addr,
+ memcpy(sa6.sin6_addr.s6_addr,
+ "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
+ memcpy(da6.sin6_addr.s6_addr+12, buf[i].addr, 4);
+ memcpy(da6.sin6_addr.s6_addr,
"\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
- memcpy(da.sin6_addr.s6_addr+12, buf[i].addr, 4);
+ memcpy(da6.sin6_addr.s6_addr+12, buf[i].addr, 4);
+ memcpy(&da4.sin_addr, buf[i].addr, 4);
+ da = &da4; dalen = sizeof da4;
+ sa = &sa4; salen = sizeof sa4;
}
- const struct policy *dpolicy = policyof(&da.sin6_addr);
- int dscope = scopeof(&da.sin6_addr);
+ const struct policy *dpolicy = policyof(&da6.sin6_addr);
+ int dscope = scopeof(&da6.sin6_addr);
int dlabel = dpolicy->label;
int dprec = dpolicy->prec;
int prefixlen = 0;
- int fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC, IPPROTO_UDP);
+ int fd = socket(family, SOCK_DGRAM|SOCK_CLOEXEC, IPPROTO_UDP);
if (fd >= 0) {
- if (!connect(fd, (void *)&da, sizeof da)) {
+ if (!connect(fd, da, dalen)) {
key |= DAS_USABLE;
- if (!getsockname(fd, (void *)&sa,
- &(socklen_t){sizeof sa})) {
- if (dscope == scopeof(&sa.sin6_addr))
+ if (!getsockname(fd, sa, &salen)) {
+ if (family == AF_INET) memcpy(
+ sa6.sin6_addr.s6_addr+12,
+ &sa4.sin_addr, 4);
+ if (dscope == scopeof(&sa6.sin6_addr))
key |= DAS_MATCHINGSCOPE;
- if (dlabel == labelof(&sa.sin6_addr))
+ if (dlabel == labelof(&sa6.sin6_addr))
key |= DAS_MATCHINGLABEL;
- prefixlen = prefixmatch(&sa.sin6_addr,
- &da.sin6_addr);
+ prefixlen = prefixmatch(&sa6.sin6_addr,
+ &da6.sin6_addr);
}
}
close(fd);
projects / musl / blobdiff