/* * lib/addr.c Network Address * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation version 2.1 * of the License. * * Copyright (c) 2003-2013 Thomas Graf */ /** * @ingroup core_types * @defgroup addr Network Address * * Abstract data type representing any kind of network address * * Related sections in the development guide: * - @core_doc{_abstract_address, Network Addresses} * * @{ * * Header * ------ * ~~~~{.c} * #include * ~~~~ */ #include #include #include #include #include /* All this DECnet stuff is stolen from iproute2, thanks to whoever wrote * this, probably Alexey. */ static inline uint16_t dn_ntohs(uint16_t addr) { union { uint8_t byte[2]; uint16_t word; } u = { .word = addr, }; return ((uint16_t) u.byte[0]) | (((uint16_t) u.byte[1]) << 8); } static inline int do_digit(char *str, uint16_t *addr, uint16_t scale, size_t *pos, size_t len, int *started) { uint16_t tmp = *addr / scale; if (*pos == len) return 1; if (((tmp) > 0) || *started || (scale == 1)) { *str = tmp + '0'; *started = 1; (*pos)++; *addr -= (tmp * scale); } return 0; } static const char *dnet_ntop(char *addrbuf, size_t addrlen, char *str, size_t len) { uint16_t addr = dn_ntohs(*(uint16_t *)addrbuf); uint16_t area = addr >> 10; size_t pos = 0; int started = 0; if (addrlen != 2) return NULL; addr &= 0x03ff; if (len == 0) return str; if (do_digit(str + pos, &area, 10, &pos, len, &started)) return str; if (do_digit(str + pos, &area, 1, &pos, len, &started)) return str; if (pos == len) return str; *(str + pos) = '.'; pos++; started = 0; if (do_digit(str + pos, &addr, 1000, &pos, len, &started)) return str; if (do_digit(str + pos, &addr, 100, &pos, len, &started)) return str; if (do_digit(str + pos, &addr, 10, &pos, len, &started)) return str; if (do_digit(str + pos, &addr, 1, &pos, len, &started)) return str; if (pos == len) return str; *(str + pos) = 0; return str; } static int dnet_num(const char *src, uint16_t * dst) { int rv = 0; int tmp; *dst = 0; while ((tmp = *src++) != 0) { tmp -= '0'; if ((tmp < 0) || (tmp > 9)) return rv; rv++; (*dst) *= 10; (*dst) += tmp; } return rv; } static inline int dnet_pton(const char *src, char *addrbuf) { uint16_t area = 0; uint16_t node = 0; int pos; pos = dnet_num(src, &area); if ((pos == 0) || (area > 63) || ((*(src + pos) != '.') && (*(src + pos) != ','))) return -NLE_INVAL; pos = dnet_num(src + pos + 1, &node); if ((pos == 0) || (node > 1023)) return -NLE_INVAL; *(uint16_t *)addrbuf = dn_ntohs((area << 10) | node); return 1; } static void addr_destroy(struct nl_addr *addr) { if (!addr) return; if (addr->a_refcnt != 1) BUG(); free(addr); } /** * @name Creating Abstract Network Addresses * @{ */ /** * Allocate empty abstract address * @arg maxsize Upper limit of the binary address to be stored * * The new address object will be empty with a prefix length of 0 and will * be capable of holding binary addresses up to the specified limit. * * @see nl_addr_build() * @see nl_addr_parse() * @see nl_addr_put() * * @return Allocated address object or NULL upon failure. */ struct nl_addr *nl_addr_alloc(size_t maxsize) { struct nl_addr *addr; addr = calloc(1, sizeof(*addr) + maxsize); if (!addr) return NULL; addr->a_refcnt = 1; addr->a_maxsize = maxsize; return addr; } /** * Allocate abstract address based on a binary address. * @arg family Address family * @arg buf Binary address * @arg size Length of binary address * * This function will allocate an abstract address capable of holding the * binary address specified. The prefix length will be set to the full * length of the binary address provided. * * @see nl_addr_alloc() * @see nl_addr_alloc_attr() * @see nl_addr_parse() * @see nl_addr_put() * * @return Allocated address object or NULL upon failure. */ struct nl_addr *nl_addr_build(int family, void *buf, size_t size) { struct nl_addr *addr; addr = nl_addr_alloc(size); if (!addr) return NULL; addr->a_family = family; addr->a_len = size; addr->a_prefixlen = size*8; if (size) memcpy(addr->a_addr, buf, size); return addr; } /** * Allocate abstract address based on Netlink attribute. * @arg nla Netlink attribute * @arg family Address family. * * Allocates an abstract address based on the specified Netlink attribute * by interpreting the payload of the Netlink attribute as the binary * address. * * This function is identical to: * @code * nl_addr_build(family, nla_data(nla), nla_len(nla)); * @endcode * * @see nl_addr_alloc() * @see nl_addr_build() * @see nl_addr_parse() * @see nl_addr_put() * * @return Allocated address object or NULL upon failure. */ struct nl_addr *nl_addr_alloc_attr(struct nlattr *nla, int family) { return nl_addr_build(family, nla_data(nla), nla_len(nla)); } /** * Allocate abstract address based on character string * @arg addrstr Address represented as character string. * @arg hint Address family hint or AF_UNSPEC. * @arg result Pointer to store resulting address. * * Regognizes the following address formats: * @code * Format Len Family * ---------------------------------------------------------------- * IPv6 address format 16 AF_INET6 * ddd.ddd.ddd.ddd 4 AF_INET * HH:HH:HH:HH:HH:HH 6 AF_LLC * AA{.|,}NNNN 2 AF_DECnet * HH:HH:HH:... variable AF_UNSPEC * @endcode * * Special values: * - none: All bits and length set to 0. * - {default|all|any}: All bits set to 0, length based on hint or * AF_INET if no hint is given. * * The prefix length may be appened at the end prefixed with a * slash, e.g. 10.0.0.0/8. * * @see nl_addr_alloc() * @see nl_addr_build() * @see nl_addr_put() * * @return 0 on success or a negative error code. */ int nl_addr_parse(const char *addrstr, int hint, struct nl_addr **result) { int err, copy = 0, len = 0, family = AF_UNSPEC; char *str, *prefix, buf[32]; struct nl_addr *addr = NULL; /* gcc ain't that smart */ str = strdup(addrstr); if (!str) { err = -NLE_NOMEM; goto errout; } prefix = strchr(str, '/'); if (prefix) *prefix = '\0'; if (!strcasecmp(str, "none")) { family = hint; goto prefix; } if (!strcasecmp(str, "default") || !strcasecmp(str, "all") || !strcasecmp(str, "any")) { len = 0; switch (hint) { case AF_INET: case AF_UNSPEC: /* Kind of a hack, we assume that if there is * no hint given the user wants to have a IPv4 * address given back. */ family = AF_INET; goto prefix; case AF_INET6: family = AF_INET6; goto prefix; case AF_LLC: family = AF_LLC; goto prefix; default: err = -NLE_AF_NOSUPPORT; goto errout; } } copy = 1; if (hint == AF_INET || hint == AF_UNSPEC) { if (inet_pton(AF_INET, str, buf) > 0) { family = AF_INET; len = 4; goto prefix; } if (hint == AF_INET) { err = -NLE_NOADDR; goto errout; } } if (hint == AF_INET6 || hint == AF_UNSPEC) { if (inet_pton(AF_INET6, str, buf) > 0) { family = AF_INET6; len = 16; goto prefix; } if (hint == AF_INET6) { err = -NLE_NOADDR; goto errout; } } if ((hint == AF_LLC || hint == AF_UNSPEC) && strchr(str, ':')) { unsigned int a, b, c, d, e, f; if (sscanf(str, "%02x:%02x:%02x:%02x:%02x:%02x", &a, &b, &c, &d, &e, &f) == 6) { family = AF_LLC; len = 6; buf[0] = (unsigned char) a; buf[1] = (unsigned char) b; buf[2] = (unsigned char) c; buf[3] = (unsigned char) d; buf[4] = (unsigned char) e; buf[5] = (unsigned char) f; goto prefix; } if (hint == AF_LLC) { err = -NLE_NOADDR; goto errout; } } if ((hint == AF_DECnet || hint == AF_UNSPEC) && (strchr(str, '.') || strchr(str, ','))) { if (dnet_pton(str, buf) > 0) { family = AF_DECnet; len = 2; goto prefix; } if (hint == AF_DECnet) { err = -NLE_NOADDR; goto errout; } } if (hint == AF_UNSPEC && strchr(str, ':')) { size_t i = 0; char *s = str, *p; for (;;) { long l = strtol(s, &p, 16); if (s == p || l > 0xff || i >= sizeof(buf)) { err = -NLE_INVAL; goto errout; } buf[i++] = (unsigned char) l; if (*p == '\0') break; s = ++p; } len = i; family = AF_UNSPEC; goto prefix; } err = -NLE_NOADDR; goto errout; prefix: addr = nl_addr_alloc(len); if (!addr) { err = -NLE_NOMEM; goto errout; } nl_addr_set_family(addr, family); if (copy) nl_addr_set_binary_addr(addr, buf, len); if (prefix) { char *p; long pl = strtol(++prefix, &p, 0); if (p == prefix) { addr_destroy(addr); err = -NLE_INVAL; goto errout; } nl_addr_set_prefixlen(addr, pl); } else nl_addr_set_prefixlen(addr, len * 8); *result = addr; err = 0; errout: free(str); return err; } /** * Clone existing abstract address object * @arg addr Abstract address object * * Allocates new abstract address representing an identical clone of an * existing address. * * @see nl_addr_alloc() * @see nl_addr_put() * * @return Allocated abstract address or NULL upon failure. */ struct nl_addr *nl_addr_clone(struct nl_addr *addr) { struct nl_addr *new; new = nl_addr_build(addr->a_family, addr->a_addr, addr->a_len); if (new) new->a_prefixlen = addr->a_prefixlen; return new; } /** @} */ /** * @name Managing Usage References * @{ */ /** * Increase the reference counter of an abstract address * @arg addr Abstract address * * Increases the reference counter of the address and thus prevents the * release of the memory resources until the reference is given back * using the function nl_addr_put(). * * @see nl_addr_put() * * @return Pointer to the existing abstract address */ struct nl_addr *nl_addr_get(struct nl_addr *addr) { addr->a_refcnt++; return addr; } /** * Decrease the reference counter of an abstract address * @arg addr Abstract addr * * @note The resources of the abstract address will be freed after the * last reference to the address has been returned. * * @see nl_addr_get() */ void nl_addr_put(struct nl_addr *addr) { if (!addr) return; if (addr->a_refcnt == 1) addr_destroy(addr); else addr->a_refcnt--; } /** * Check whether an abstract address is shared. * @arg addr Abstract address object. * * @return Non-zero if the abstract address is shared, otherwise 0. */ int nl_addr_shared(struct nl_addr *addr) { return addr->a_refcnt > 1; } /** @} */ /** * @name Miscellaneous * @{ */ /** * Compare abstract addresses * @arg a An abstract address * @arg b Another abstract address * * Verifies whether the address family, address length, prefix length, and * binary addresses of two abstract addresses matches. * * @note This function will *not* respect the prefix length in the sense * that only the actual prefix will be compared. Please refer to the * nl_addr_cmp_prefix() function if you require this functionality. * * @see nl_addr_cmp_prefix() * * @return Integer less than, equal to or greather than zero if the two * addresses match. */ int nl_addr_cmp(struct nl_addr *a, struct nl_addr *b) { int d = a->a_family - b->a_family; if (d == 0) { d = a->a_len - b->a_len; if (a->a_len && d == 0) { d = memcmp(a->a_addr, b->a_addr, a->a_len); if (d == 0) return (a->a_prefixlen - b->a_prefixlen); } } return d; } /** * Compare the prefix of two abstract addresses * @arg a An abstract address * @arg b Another abstract address * * Verifies whether the address family and the binary address covered by * the smaller prefix length of the two abstract addresses matches. * * @see nl_addr_cmp() * * @return Integer less than, equal to or greather than zero if the two * addresses match. */ int nl_addr_cmp_prefix(struct nl_addr *a, struct nl_addr *b) { int d = a->a_family - b->a_family; if (d == 0) { int len = min(a->a_prefixlen, b->a_prefixlen); int bytes = len / 8; d = memcmp(a->a_addr, b->a_addr, bytes); if (d == 0 && (len % 8) != 0) { int mask = (0xFF00 >> (len % 8)) & 0xFF; d = (a->a_addr[bytes] & mask) - (b->a_addr[bytes] & mask); } } return d; } /** * Returns true if the address consists of all zeros * @arg addr Abstract address * * @return 1 if the binary address consists of all zeros, 0 otherwise. */ int nl_addr_iszero(struct nl_addr *addr) { unsigned int i; for (i = 0; i < addr->a_len; i++) if (addr->a_addr[i]) return 0; return 1; } /** * Check if address string is parseable for a specific address family * @arg addr Address represented as character string. * @arg family Desired address family. * * @return 1 if the address is parseable assuming the specified address family, * otherwise 0 is returned. */ int nl_addr_valid(char *addr, int family) { int ret; char buf[32]; switch (family) { case AF_INET: case AF_INET6: ret = inet_pton(family, addr, buf); if (ret <= 0) return 0; break; case AF_DECnet: ret = dnet_pton(addr, buf); if (ret <= 0) return 0; break; case AF_LLC: if (sscanf(addr, "%*02x:%*02x:%*02x:%*02x:%*02x:%*02x") != 6) return 0; break; } return 1; } /** * Guess address family of abstract address based on address size * @arg addr Abstract address object. * * @return Numeric address family or AF_UNSPEC */ int nl_addr_guess_family(struct nl_addr *addr) { switch (addr->a_len) { case 4: return AF_INET; case 6: return AF_LLC; case 16: return AF_INET6; default: return AF_UNSPEC; } } /** * Fill out sockaddr structure with values from abstract address object. * @arg addr Abstract address object. * @arg sa Destination sockaddr structure buffer. * @arg salen Length of sockaddr structure buffer. * * Fills out the specified sockaddr structure with the data found in the * specified abstract address. The salen argument needs to be set to the * size of sa but will be modified to the actual size used during before * the function exits. * * @return 0 on success or a negative error code */ int nl_addr_fill_sockaddr(struct nl_addr *addr, struct sockaddr *sa, socklen_t *salen) { switch (addr->a_family) { case AF_INET: { struct sockaddr_in *sai = (struct sockaddr_in *) sa; if (*salen < sizeof(*sai)) return -NLE_INVAL; sai->sin_family = addr->a_family; memcpy(&sai->sin_addr, addr->a_addr, 4); *salen = sizeof(*sai); } break; case AF_INET6: { struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) sa; if (*salen < sizeof(*sa6)) return -NLE_INVAL; sa6->sin6_family = addr->a_family; memcpy(&sa6->sin6_addr, addr->a_addr, 16); *salen = sizeof(*sa6); } break; default: return -NLE_INVAL; } return 0; } /** @} */ /** * @name Getting Information About Addresses * @{ */ /** * Call getaddrinfo() for an abstract address object. * @arg addr Abstract address object. * @arg result Pointer to store resulting address list. * * Calls getaddrinfo() for the specified abstract address in AI_NUMERICHOST * mode. * * @note The caller is responsible for freeing the linked list using the * interface provided by getaddrinfo(3). * * @return 0 on success or a negative error code. */ int nl_addr_info(struct nl_addr *addr, struct addrinfo **result) { int err; char buf[INET6_ADDRSTRLEN+5]; struct addrinfo hint = { .ai_flags = AI_NUMERICHOST, .ai_family = addr->a_family, }; nl_addr2str(addr, buf, sizeof(buf)); err = getaddrinfo(buf, NULL, &hint, result); if (err != 0) { switch (err) { case EAI_ADDRFAMILY: return -NLE_AF_NOSUPPORT; case EAI_AGAIN: return -NLE_AGAIN; case EAI_BADFLAGS: return -NLE_INVAL; case EAI_FAIL: return -NLE_NOADDR; case EAI_FAMILY: return -NLE_AF_NOSUPPORT; case EAI_MEMORY: return -NLE_NOMEM; case EAI_NODATA: return -NLE_NOADDR; case EAI_NONAME: return -NLE_OBJ_NOTFOUND; case EAI_SERVICE: return -NLE_OPNOTSUPP; case EAI_SOCKTYPE: return -NLE_BAD_SOCK; default: return -NLE_FAILURE; } } return 0; } /** * Resolve abstract address object to a name using getnameinfo(). * @arg addr Abstract address object. * @arg host Destination buffer for host name. * @arg hostlen Length of destination buffer. * * Resolves the abstract address to a name and writes the looked up result * into the host buffer. getnameinfo() is used to perform the lookup and * is put into NI_NAMEREQD mode so the function will fail if the lookup * couldn't be performed. * * @return 0 on success or a negative error code. */ int nl_addr_resolve(struct nl_addr *addr, char *host, size_t hostlen) { int err; struct sockaddr_in6 buf; socklen_t salen = sizeof(buf); err = nl_addr_fill_sockaddr(addr, (struct sockaddr *) &buf, &salen); if (err < 0) return err; err = getnameinfo((struct sockaddr *) &buf, salen, host, hostlen, NULL, 0, NI_NAMEREQD); if (err < 0) return nl_syserr2nlerr(err); return 0; } /** @} */ /** * @name Attributes * @{ */ /** * Set address family * @arg addr Abstract address object * @arg family Address family * * @see nl_addr_get_family() */ void nl_addr_set_family(struct nl_addr *addr, int family) { addr->a_family = family; } /** * Return address family * @arg addr Abstract address object * * @see nl_addr_set_family() * * @return The numeric address family or `AF_UNSPEC` */ int nl_addr_get_family(struct nl_addr *addr) { return addr->a_family; } /** * Set binary address of abstract address object. * @arg addr Abstract address object. * @arg buf Buffer containing binary address. * @arg len Length of buffer containing binary address. * * Modifies the binary address portion of the abstract address. The * abstract address must be capable of holding the required amount * or this function will fail. * * @note This function will *not* modify the prefix length. It is within * the responsibility of the caller to set the prefix length to the * desirable length. * * @see nl_addr_alloc() * @see nl_addr_get_binary_addr() * @see nl_addr_get_len() * * @return 0 on success or a negative error code. */ int nl_addr_set_binary_addr(struct nl_addr *addr, void *buf, size_t len) { if (len > addr->a_maxsize) return -NLE_RANGE; addr->a_len = len; memset(addr->a_addr, 0, addr->a_maxsize); if (len) memcpy(addr->a_addr, buf, len); return 0; } /** * Get binary address of abstract address object. * @arg addr Abstract address object. * * @see nl_addr_set_binary_addr() * @see nl_addr_get_len() * * @return Pointer to binary address of length nl_addr_get_len() */ void *nl_addr_get_binary_addr(struct nl_addr *addr) { return addr->a_addr; } /** * Get length of binary address of abstract address object. * @arg addr Abstract address object. * * @see nl_addr_get_binary_addr() * @see nl_addr_set_binary_addr() */ unsigned int nl_addr_get_len(struct nl_addr *addr) { return addr->a_len; } /** * Set the prefix length of an abstract address * @arg addr Abstract address object * @arg prefixlen New prefix length * * @see nl_addr_get_prefixlen() */ void nl_addr_set_prefixlen(struct nl_addr *addr, int prefixlen) { addr->a_prefixlen = prefixlen; } /** * Return prefix length of abstract address object. * @arg addr Abstract address object * * @see nl_addr_set_prefixlen() */ unsigned int nl_addr_get_prefixlen(struct nl_addr *addr) { return addr->a_prefixlen; } /** @} */ /** * @name Translations to Strings * @{ */ /** * Convert abstract address object to character string. * @arg addr Abstract address object. * @arg buf Destination buffer. * @arg size Size of destination buffer. * * Converts an abstract address to a character string and stores * the result in the specified destination buffer. * * @return Address represented in ASCII stored in destination buffer. */ char *nl_addr2str(struct nl_addr *addr, char *buf, size_t size) { unsigned int i; char tmp[16]; if (!addr || !addr->a_len) { snprintf(buf, size, "none"); if (addr) goto prefix; else return buf; } switch (addr->a_family) { case AF_INET: inet_ntop(AF_INET, addr->a_addr, buf, size); break; case AF_INET6: inet_ntop(AF_INET6, addr->a_addr, buf, size); break; case AF_DECnet: dnet_ntop(addr->a_addr, addr->a_len, buf, size); break; case AF_LLC: default: snprintf(buf, size, "%02x", (unsigned char) addr->a_addr[0]); for (i = 1; i < addr->a_len; i++) { snprintf(tmp, sizeof(tmp), ":%02x", (unsigned char) addr->a_addr[i]); strncat(buf, tmp, size - strlen(buf) - 1); } break; } prefix: if (addr->a_prefixlen != (8 * addr->a_len)) { snprintf(tmp, sizeof(tmp), "/%u", addr->a_prefixlen); strncat(buf, tmp, size - strlen(buf) - 1); } return buf; } /** @} */ /** * @name Address Family Transformations * @{ */ static const struct trans_tbl afs[] = { __ADD(AF_UNSPEC,unspec) __ADD(AF_UNIX,unix) __ADD(AF_INET,inet) __ADD(AF_AX25,ax25) __ADD(AF_IPX,ipx) __ADD(AF_APPLETALK,appletalk) __ADD(AF_NETROM,netrom) __ADD(AF_BRIDGE,bridge) __ADD(AF_ATMPVC,atmpvc) __ADD(AF_X25,x25) __ADD(AF_INET6,inet6) __ADD(AF_ROSE,rose) __ADD(AF_DECnet,decnet) __ADD(AF_NETBEUI,netbeui) __ADD(AF_SECURITY,security) __ADD(AF_KEY,key) __ADD(AF_NETLINK,netlink) __ADD(AF_PACKET,packet) __ADD(AF_ASH,ash) __ADD(AF_ECONET,econet) __ADD(AF_ATMSVC,atmsvc) #ifdef AF_RDS __ADD(AF_RDS,rds) #endif __ADD(AF_SNA,sna) __ADD(AF_IRDA,irda) __ADD(AF_PPPOX,pppox) __ADD(AF_WANPIPE,wanpipe) __ADD(AF_LLC,llc) #ifdef AF_CAN __ADD(AF_CAN,can) #endif #ifdef AF_TIPC __ADD(AF_TIPC,tipc) #endif __ADD(AF_BLUETOOTH,bluetooth) #ifdef AF_IUCV __ADD(AF_IUCV,iucv) #endif #ifdef AF_RXRPC __ADD(AF_RXRPC,rxrpc) #endif #ifdef AF_ISDN __ADD(AF_ISDN,isdn) #endif #ifdef AF_PHONET __ADD(AF_PHONET,phonet) #endif #ifdef AF_IEEE802154 __ADD(AF_IEEE802154,ieee802154) #endif #ifdef AF_CAIF __ADD(AF_CAIF,caif) #endif #ifdef AF_ALG __ADD(AF_ALG,alg) #endif #ifdef AF_NFC __ADD(AF_NFC,nfc) #endif }; char *nl_af2str(int family, char *buf, size_t size) { return __type2str(family, buf, size, afs, ARRAY_SIZE(afs)); } int nl_str2af(const char *name) { int fam = __str2type(name, afs, ARRAY_SIZE(afs)); return fam >= 0 ? fam : -EINVAL; } /** @} */ /** @} */