diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/addrfam.c | 233 | ||||
| -rw-r--r-- | src/adns.h | 58 |
2 files changed, 291 insertions, 0 deletions
diff --git a/src/addrfam.c b/src/addrfam.c index f606612..a357f9e 100644 --- a/src/addrfam.c +++ b/src/addrfam.c @@ -28,11 +28,15 @@ #include <errno.h> #include <limits.h> #include <unistd.h> +#include <inttypes.h> +#include <stddef.h> +#include <stdbool.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> +#include <net/if.h> #include "internal.h" @@ -210,3 +214,232 @@ void adns__sockaddr_inject(const union gen_addr *a, int port, unknown_af(sa->sa_family); } } + +/* + * 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; +} @@ -66,6 +66,7 @@ #include <netinet/in.h> #include <sys/time.h> #include <unistd.h> +#include <net/if.h> #ifdef __cplusplus extern "C" { /* I really dislike this - iwj. */ @@ -101,6 +102,9 @@ typedef enum { /* In general, or together the desired flags: */ adns_qf_quotefail_cname=0x00000080,/* refuse if quote-req chars in CNAME we go via */ adns_qf_cname_loose= 0x00000100,/* allow refs to CNAMEs - without, get _s_cname */ adns_qf_cname_forbid= 0x00000200,/* don't follow CNAMEs, instead give _s_cname */ + adns_qf_addrlit_scope_forbid=0x00002000,/* forbid %<scope> in IPv6 literals */ + adns_qf_addrlit_scope_numeric=0x00004000,/* %<scope> may only be numeric */ + adns_qf_addrlit_ipv4_quadonly=0x00008000,/* reject non-dotted-quad ipv4 */ adns__qf_internalmask= 0x0ff00000 } adns_queryflags; @@ -631,6 +635,60 @@ void adns_finish(adns_state ads); * they will be cancelled. */ +#define ADNS_ADDR2TEXT_BUFLEN \ + (INET6_ADDRSTRLEN + 1/*%*/ \ + + ((IF_NAMESIZE-1) > 9 ? (IF_NAMESIZE-1) : 9/*uint32*/) \ + + 1/* nul; included in IF_NAMESIZE */) + +int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags, + struct sockaddr *sa_r, + socklen_t *salen_io /* updated iff OK or ENOSPC */); +int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags, + char *buffer, int *buflen_io /* updated ONLY on ENOSPC */, + int *port_r /* may be 0 */); + /* + * port is always in host byte order and is simply copied to and + * from the appropriate sockaddr field (byteswapped as necessary). + * + * The only flags supported are adns_qf_addrlit_...; others are + * ignored. + * + * Error return values are: + * + * ENOSPC Output buffer is too small. Can only happen if + * *buflen_io < ADNS_ADDR2TEXT_BUFLEN or + * *salen_io < sizeof(adns_sockaddr). On return, + * *buflen_io or *salen_io has been updated by adns. + * + * EINVAL text has invalid syntax. + * + * text represents an address family not supported by + * this version of adns. + * + * Scoped address supplied (text contained "%" or + * sin6_scope_id nonzero) but caller specified + * adns_qf_addrlit_scope_forbid. + * + * Scope name (rather than number) supplied in text but + * caller specified adns_qf_addrlit_scope_numeric. + * + * EAFNOSUPPORT sa->sa_family is not supported (addr2text only). + * + * Only if neither adns_qf_addrlit_scope_forbid nor + * adns_qf_addrlit_scope_numeric are set: + * + * ENOSYS Scope name supplied in text but IPv6 address part of + * sockaddr is not a link local address. + * + * ENXIO Scope name supplied in text but if_nametoindex + * said it wasn't a valid local interface name. + * + * EIO Scoped address supplied but if_nametoindex failed + * in an unexpected way; adns has printed a message to + * stderr. + * + * any other if_nametoindex failed in a more-or-less expected way. + */ void adns_forallqueries_begin(adns_state ads); adns_query adns_forallqueries_next(adns_state ads, void **context_r); |