+
+/*
+ * addr2text and text2addr
+ */
+
+#define ADDRFAM_DEBUG
+#ifdef ADDRFAM_DEBUG
+static void af_debug_func(const char *fmt, ...) {
+ int esave= errno;
+ va_list al;
+ va_start(al,fmt);
+ vfprintf(stderr,fmt,al);
+ va_end(al);
+ errno= esave;
+}
+# define af_debug(fmt,...) \
+ (af_debug_func("%s: " fmt "\n", __func__, __VA_ARGS__))
+#else
+# define af_debug(fmt,...) ((void)("" fmt "", __VA_ARGS__))
+#endif
+
+static bool addrtext_our_errno(int e) {
+ return
+ e==EAFNOSUPPORT ||
+ e==EINVAL ||
+ e==ENOSPC ||
+ e==ENOSYS;
+}
+
+static bool addrtext_scope_use_ifname(const struct sockaddr *sa) {
+ const struct in6_addr *in6= &CSIN6(sa)->sin6_addr;
+ return
+ IN6_IS_ADDR_LINKLOCAL(in6) ||
+ IN6_IS_ADDR_MC_LINKLOCAL(in6);
+}
+
+int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags,
+ struct sockaddr *sa, socklen_t *salen_io) {
+ int af;
+ char copybuf[INET6_ADDRSTRLEN];
+ const char *parse=text;
+ const char *scopestr=0;
+ socklen_t needlen;
+ void *dst;
+ uint16_t *portp;
+
+#define INVAL(how) do{ \
+ af_debug("invalid: %s: `%s'", how, text); \
+ return EINVAL; \
+}while(0)
+
+#define AFCORE(INETx,SINx,sinx) \
+ af= AF_##INETx; \
+ dst = &SINx(sa)->sinx##_addr; \
+ portp = &SINx(sa)->sinx##_port; \
+ needlen= sizeof(*SINx(sa));
+
+ if (!strchr(text, ':')) { /* INET */
+
+ AFCORE(INET,SIN,sin);
+
+ } else { /* INET6 */
+
+ AFCORE(INET6,SIN6,sin6);
+
+ const char *percent= strchr(text, '%');
+ if (percent) {
+ ptrdiff_t lhslen = percent - text;
+ if (lhslen >= INET6_ADDRSTRLEN) INVAL("scoped addr lhs too long");
+ memcpy(copybuf, text, lhslen);
+ copybuf[lhslen]= 0;
+
+ parse= copybuf;
+ scopestr= percent+1;
+
+ af_debug("will parse scoped addr `%s' %% `%s'", parse, scopestr);
+ }
+
+ }
+
+#undef AFCORE
+
+ if (scopestr && (flags & adns_qf_addrlit_scope_forbid))
+ INVAL("scoped addr but _scope_forbid");
+
+ if (*salen_io < needlen) {
+ *salen_io = needlen;
+ return ENOSPC;
+ }
+
+ memset(sa, 0, needlen);
+
+ sa->sa_family= af;
+ *portp = htons(port);
+
+ if (af == AF_INET && !(flags & adns_qf_addrlit_ipv4_quadonly)) {
+ /* we have to use inet_aton to deal with non-dotted-quad literals */
+ int r= inet_aton(parse,&SIN(sa)->sin_addr);
+ if (!r) INVAL("inet_aton rejected");
+ } else {
+ int r= inet_pton(af,parse,dst);
+ if (!r) INVAL("inet_pton rejected");
+ assert(r>0);
+ }
+
+ if (scopestr) {
+ errno=0;
+ char *ep;
+ unsigned long scope= strtoul(scopestr,&ep,10);
+ if (errno==ERANGE) INVAL("numeric scope id too large for unsigned long");
+ assert(!errno);
+ if (!*ep) {
+ if (scope > ~(uint32_t)0)
+ INVAL("numeric scope id too large for uint32_t");
+ } else { /* !!*ep */
+ if (flags & adns_qf_addrlit_scope_numeric)
+ INVAL("non-numeric scope but _scope_numeric");
+ if (!addrtext_scope_use_ifname(sa)) {
+ af_debug("cannot convert non-numeric scope"
+ " in non-link-local addr `%s'", text);
+ return ENOSYS;
+ }
+ errno= 0;
+ scope= if_nametoindex(scopestr);
+ if (!scope) {
+ /* RFC3493 says "No errors are defined". It's not clear
+ * whether that is supposed to mean if_nametoindex "can't
+ * fail" (other than by the supplied name not being that of an
+ * interface) which seems unrealistic, or that it conflates
+ * all its errors together by failing to set errno, or simply
+ * that they didn't bother to document the errors.
+ *
+ * glibc, FreeBSD and OpenBSD all set errno (to ENXIO when
+ * appropriate). See Debian bug #749349.
+ *
+ * We attempt to deal with this by clearing errno to start
+ * with, and then perhaps mapping the results. */
+ af_debug("if_nametoindex rejected scope name (errno=%s)",
+ strerror(errno));
+ if (errno==0) {
+ return ENXIO;
+ } else if (addrtext_our_errno(errno)) {
+ /* we use these for other purposes, urgh. */
+ perror("adns: adns_text2addr: if_nametoindex"
+ " failed with unexpected error");
+ return EIO;
+ } else {
+ return errno;
+ }
+ } else { /* ix>0 */
+ if (scope > ~(uint32_t)0) {
+ fprintf(stderr,"adns: adns_text2addr: if_nametoindex"
+ " returned an interface index >=2^32 which will not fit"
+ " in sockaddr_in6.sin6_scope_id");
+ return EIO;
+ }
+ }
+ } /* else; !!*ep */
+
+ SIN6(sa)->sin6_scope_id= scope;
+ } /* if (scopestr) */
+
+ *salen_io = needlen;
+ return 0;
+}
+
+int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags,
+ char *buffer, int *buflen_io, int *port_r) {
+ const void *src;
+ int port;
+
+ if (*buflen_io < ADNS_ADDR2TEXT_BUFLEN) {
+ *buflen_io = ADNS_ADDR2TEXT_BUFLEN;
+ return ENOSPC;
+ }
+
+ switch (sa->sa_family) {
+ AF_CASES(af);
+ af_inet: src= &CSIN(sa)->sin_addr; port= CSIN(sa)->sin_port; break;
+ af_inet6: src= &CSIN6(sa)->sin6_addr; port= CSIN6(sa)->sin6_port; break;
+ default: return EAFNOSUPPORT;
+ }
+
+ const char *ok= inet_ntop(sa->sa_family, src, buffer, *buflen_io);
+ assert(ok);
+
+ if (sa->sa_family == AF_INET6) {
+ uint32_t scope = CSIN6(sa)->sin6_scope_id;
+ if (scope) {
+ if (flags & adns_qf_addrlit_scope_forbid)
+ return EINVAL;
+ int scopeoffset = strlen(buffer);
+ int remain = *buflen_io - scopeoffset;
+ char *scopeptr = buffer + scopeoffset;
+ assert(remain >= IF_NAMESIZE+1/*%*/);
+ *scopeptr++= '%'; remain--;
+ bool parsedname = 0;
+ af_debug("will print scoped addr %s %% %"PRIu32"", buffer, scope);
+ if (scope <= UINT_MAX /* so we can pass it to if_indextoname */
+ && !(flags & adns_qf_addrlit_scope_numeric)
+ && addrtext_scope_use_ifname(sa)) {
+ parsedname = if_indextoname(scope, scopeptr);
+ if (!parsedname) {
+ af_debug("if_indextoname rejected scope (errno=%s)",
+ strerror(errno));
+ if (errno==ENXIO) {
+ /* fair enough, show it as a number then */
+ } else if (addrtext_our_errno(errno)) {
+ /* we use these for other purposes, urgh. */
+ perror("adns: adns_addr2text: if_indextoname"
+ " failed with unexpected error");
+ return EIO;
+ } else {
+ return errno;
+ }
+ }
+ }
+ if (!parsedname) {
+ int r = snprintf(scopeptr, remain,
+ "%"PRIu32"", scope);
+ assert(r < *buflen_io - scopeoffset);
+ }
+ af_debug("printed scoped addr `%s'", buffer);
+ }
+ }
+
+ if (port_r) *port_r= ntohs(port);
+ return 0;
+}
~ianmdlvl / adns.git / commitdiff