diff options
Diffstat (limited to 'src/network/lookup_name.c')
| -rw-r--r-- | src/network/lookup_name.c | 71 |
1 files changed, 46 insertions, 25 deletions
diff --git a/src/network/lookup_name.c b/src/network/lookup_name.c index c93263a9..35218185 100644 --- a/src/network/lookup_name.c +++ b/src/network/lookup_name.c @@ -50,7 +50,7 @@ static int name_from_hosts(struct address buf[static MAXADDRS], char canon[stati { char line[512]; size_t l = strlen(name); - int cnt = 0, badfam = 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) { @@ -79,15 +79,20 @@ static int name_from_hosts(struct address buf[static MAXADDRS], char canon[stati case 0: continue; default: - badfam = EAI_NONAME; - continue; + 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 ? cnt : badfam; @@ -97,45 +102,50 @@ struct dpc_ctx { struct address *addrs; char *canon; int cnt; + int rrtype; }; #define RR_A 1 #define RR_CNAME 5 #define RR_AAAA 28 -static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet) +#define ABUF_SIZE 4800 + +static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet, int plen) { char tmp[256]; + int family; struct dpc_ctx *ctx = c; - if (ctx->cnt >= MAXADDRS) return -1; + if (rr == RR_CNAME) { + if (__dn_expand(packet, (const unsigned char *)packet + plen, + data, tmp, sizeof tmp) > 0 && is_valid_hostname(tmp)) + strcpy(ctx->canon, tmp); + return 0; + } + if (ctx->cnt >= MAXADDRS) return 0; + if (rr != ctx->rrtype) return 0; switch (rr) { case RR_A: 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); + family = AF_INET; break; case RR_AAAA: 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, - data, tmp, sizeof tmp) > 0 && is_valid_hostname(tmp)) - strcpy(ctx->canon, tmp); + family = AF_INET6; break; } + ctx->addrs[ctx->cnt].family = family; + ctx->addrs[ctx->cnt].scopeid = 0; + memcpy(ctx->addrs[ctx->cnt++].addr, data, len); return 0; } 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 }; static const struct { int af; int rr; } afrr[2] = { @@ -148,7 +158,12 @@ static int name_from_dns(struct address buf[static MAXADDRS], char canon[static qlens[nq] = __res_mkquery(0, name, 1, afrr[i].rr, 0, 0, 0, qbuf[nq], sizeof *qbuf); if (qlens[nq] == -1) - return EAI_NONAME; + 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++; } } @@ -156,14 +171,20 @@ static int name_from_dns(struct address buf[static MAXADDRS], char canon[static if (__res_msend_rc(nq, qp, qlens, ap, alens, sizeof *abuf, conf) < 0) return EAI_SYSTEM; - for (i=0; i<nq; i++) + 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=nq-1; i>=0; i--) { + ctx.rrtype = qtypes[i]; + if (alens[i] > sizeof(abuf[i])) alens[i] = sizeof abuf[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) |