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Diffstat (limited to 'lwip/src/api/netdb.c')
| -rw-r--r-- | lwip/src/api/netdb.c | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/lwip/src/api/netdb.c b/lwip/src/api/netdb.c new file mode 100644 index 0000000..dfc5203 --- /dev/null +++ b/lwip/src/api/netdb.c @@ -0,0 +1,454 @@ +/** + * @file + * API functions for name resolving + * + * @defgroup netdbapi NETDB API + * @ingroup socket + */ + +/* + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Simon Goldschmidt + * + */ + +#include "lwip/netdb.h" + +#if LWIP_DNS && LWIP_SOCKET + +#include "lwip/err.h" +#include "lwip/mem.h" +#include "lwip/memp.h" +#include "lwip/ip_addr.h" +#include "lwip/api.h" +#include "lwip/dns.h" + +#include <string.h> /* memset */ +#include <stdlib.h> /* atoi */ + +/** helper struct for gethostbyname_r to access the char* buffer */ +struct gethostbyname_r_helper { + ip_addr_t *addr_list[2]; + ip_addr_t addr; + char *aliases; +}; + +/** h_errno is exported in netdb.h for access by applications. */ +#if LWIP_DNS_API_DECLARE_H_ERRNO +int h_errno; +#endif /* LWIP_DNS_API_DECLARE_H_ERRNO */ + +/** define "hostent" variables storage: 0 if we use a static (but unprotected) + * set of variables for lwip_gethostbyname, 1 if we use a local storage */ +#ifndef LWIP_DNS_API_HOSTENT_STORAGE +#define LWIP_DNS_API_HOSTENT_STORAGE 0 +#endif + +/** define "hostent" variables storage */ +#if LWIP_DNS_API_HOSTENT_STORAGE +#define HOSTENT_STORAGE +#else +#define HOSTENT_STORAGE static +#endif /* LWIP_DNS_API_STATIC_HOSTENT */ + +/** + * Returns an entry containing addresses of address family AF_INET + * for the host with name name. + * Due to dns_gethostbyname limitations, only one address is returned. + * + * @param name the hostname to resolve + * @return an entry containing addresses of address family AF_INET + * for the host with name name + */ +struct hostent * +lwip_gethostbyname(const char *name) +{ + err_t err; + ip_addr_t addr; + + /* buffer variables for lwip_gethostbyname() */ + HOSTENT_STORAGE struct hostent s_hostent; + HOSTENT_STORAGE char *s_aliases; + HOSTENT_STORAGE ip_addr_t s_hostent_addr; + HOSTENT_STORAGE ip_addr_t *s_phostent_addr[2]; + HOSTENT_STORAGE char s_hostname[DNS_MAX_NAME_LENGTH + 1]; + + /* query host IP address */ + err = netconn_gethostbyname(name, &addr); + if (err != ERR_OK) { + LWIP_DEBUGF(DNS_DEBUG, ("lwip_gethostbyname(%s) failed, err=%d\n", name, err)); + h_errno = HOST_NOT_FOUND; + return NULL; + } + + /* fill hostent */ + s_hostent_addr = addr; + s_phostent_addr[0] = &s_hostent_addr; + s_phostent_addr[1] = NULL; + strncpy(s_hostname, name, DNS_MAX_NAME_LENGTH); + s_hostname[DNS_MAX_NAME_LENGTH] = 0; + s_hostent.h_name = s_hostname; + s_aliases = NULL; + s_hostent.h_aliases = &s_aliases; + s_hostent.h_addrtype = AF_INET; + s_hostent.h_length = sizeof(ip_addr_t); + s_hostent.h_addr_list = (char **)&s_phostent_addr; + +#if DNS_DEBUG + /* dump hostent */ + LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_name == %s\n", s_hostent.h_name)); + LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_aliases == %p\n", (void *)s_hostent.h_aliases)); + /* h_aliases are always empty */ + LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addrtype == %d\n", s_hostent.h_addrtype)); + LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_length == %d\n", s_hostent.h_length)); + LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list == %p\n", (void *)s_hostent.h_addr_list)); + if (s_hostent.h_addr_list != NULL) { + u8_t idx; + for (idx = 0; s_hostent.h_addr_list[idx]; idx++) { + LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list[%i] == %p\n", idx, s_hostent.h_addr_list[idx])); + LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list[%i]-> == %s\n", idx, ipaddr_ntoa((ip_addr_t *)s_hostent.h_addr_list[idx]))); + } + } +#endif /* DNS_DEBUG */ + +#if LWIP_DNS_API_HOSTENT_STORAGE + /* this function should return the "per-thread" hostent after copy from s_hostent */ + return sys_thread_hostent(&s_hostent); +#else + return &s_hostent; +#endif /* LWIP_DNS_API_HOSTENT_STORAGE */ +} + +/** + * Thread-safe variant of lwip_gethostbyname: instead of using a static + * buffer, this function takes buffer and errno pointers as arguments + * and uses these for the result. + * + * @param name the hostname to resolve + * @param ret pre-allocated struct where to store the result + * @param buf pre-allocated buffer where to store additional data + * @param buflen the size of buf + * @param result pointer to a hostent pointer that is set to ret on success + * and set to zero on error + * @param h_errnop pointer to an int where to store errors (instead of modifying + * the global h_errno) + * @return 0 on success, non-zero on error, additional error information + * is stored in *h_errnop instead of h_errno to be thread-safe + */ +int +lwip_gethostbyname_r(const char *name, struct hostent *ret, char *buf, + size_t buflen, struct hostent **result, int *h_errnop) +{ + err_t err; + struct gethostbyname_r_helper *h; + char *hostname; + size_t namelen; + int lh_errno; + + if (h_errnop == NULL) { + /* ensure h_errnop is never NULL */ + h_errnop = &lh_errno; + } + + if (result == NULL) { + /* not all arguments given */ + *h_errnop = EINVAL; + return -1; + } + /* first thing to do: set *result to nothing */ + *result = NULL; + if ((name == NULL) || (ret == NULL) || (buf == NULL)) { + /* not all arguments given */ + *h_errnop = EINVAL; + return -1; + } + + namelen = strlen(name); + if (buflen < (sizeof(struct gethostbyname_r_helper) + LWIP_MEM_ALIGN_BUFFER(namelen + 1))) { + /* buf can't hold the data needed + a copy of name */ + *h_errnop = ERANGE; + return -1; + } + + h = (struct gethostbyname_r_helper *)LWIP_MEM_ALIGN(buf); + hostname = ((char *)h) + sizeof(struct gethostbyname_r_helper); + + /* query host IP address */ + err = netconn_gethostbyname(name, &h->addr); + if (err != ERR_OK) { + LWIP_DEBUGF(DNS_DEBUG, ("lwip_gethostbyname(%s) failed, err=%d\n", name, err)); + *h_errnop = HOST_NOT_FOUND; + return -1; + } + + /* copy the hostname into buf */ + MEMCPY(hostname, name, namelen); + hostname[namelen] = 0; + + /* fill hostent */ + h->addr_list[0] = &h->addr; + h->addr_list[1] = NULL; + h->aliases = NULL; + ret->h_name = hostname; + ret->h_aliases = &h->aliases; + ret->h_addrtype = AF_INET; + ret->h_length = sizeof(ip_addr_t); + ret->h_addr_list = (char **)&h->addr_list; + + /* set result != NULL */ + *result = ret; + + /* return success */ + return 0; +} + +/** + * Frees one or more addrinfo structures returned by getaddrinfo(), along with + * any additional storage associated with those structures. If the ai_next field + * of the structure is not null, the entire list of structures is freed. + * + * @param ai struct addrinfo to free + */ +void +lwip_freeaddrinfo(struct addrinfo *ai) +{ + struct addrinfo *next; + + while (ai != NULL) { + next = ai->ai_next; + memp_free(MEMP_NETDB, ai); + ai = next; + } +} + +/** + * Translates the name of a service location (for example, a host name) and/or + * a service name and returns a set of socket addresses and associated + * information to be used in creating a socket with which to address the + * specified service. + * Memory for the result is allocated internally and must be freed by calling + * lwip_freeaddrinfo()! + * + * Due to a limitation in dns_gethostbyname, only the first address of a + * host is returned. + * Also, service names are not supported (only port numbers)! + * + * @param nodename descriptive name or address string of the host + * (may be NULL -> local address) + * @param servname port number as string of NULL + * @param hints structure containing input values that set socktype and protocol + * @param res pointer to a pointer where to store the result (set to NULL on failure) + * @return 0 on success, non-zero on failure + * + * @todo: implement AI_V4MAPPED, AI_ADDRCONFIG + */ +int +lwip_getaddrinfo(const char *nodename, const char *servname, + const struct addrinfo *hints, struct addrinfo **res) +{ + err_t err; + ip_addr_t addr; + struct addrinfo *ai; + struct sockaddr_storage *sa = NULL; + int port_nr = 0; + size_t total_size; + size_t namelen = 0; + int ai_family; + + if (res == NULL) { + return EAI_FAIL; + } + *res = NULL; + if ((nodename == NULL) && (servname == NULL)) { + return EAI_NONAME; + } + + if (hints != NULL) { + ai_family = hints->ai_family; + if ((ai_family != AF_UNSPEC) +#if LWIP_IPV4 + && (ai_family != AF_INET) +#endif /* LWIP_IPV4 */ +#if LWIP_IPV6 + && (ai_family != AF_INET6) +#endif /* LWIP_IPV6 */ + ) { + return EAI_FAMILY; + } + } else { + ai_family = AF_UNSPEC; + } + + if (servname != NULL) { + /* service name specified: convert to port number + * @todo?: currently, only ASCII integers (port numbers) are supported (AI_NUMERICSERV)! */ + port_nr = atoi(servname); + if ((port_nr <= 0) || (port_nr > 0xffff)) { + return EAI_SERVICE; + } + } + + if (nodename != NULL) { + /* service location specified, try to resolve */ + if ((hints != NULL) && (hints->ai_flags & AI_NUMERICHOST)) { + /* no DNS lookup, just parse for an address string */ + if (!ipaddr_aton(nodename, &addr)) { + return EAI_NONAME; + } +#if LWIP_IPV4 && LWIP_IPV6 + if ((IP_IS_V6_VAL(addr) && ai_family == AF_INET) || + (IP_IS_V4_VAL(addr) && ai_family == AF_INET6)) { + return EAI_NONAME; + } +#endif /* LWIP_IPV4 && LWIP_IPV6 */ + } else { +#if LWIP_IPV4 && LWIP_IPV6 + /* AF_UNSPEC: prefer IPv4 */ + u8_t type = NETCONN_DNS_IPV4_IPV6; + if (ai_family == AF_INET) { + type = NETCONN_DNS_IPV4; + } else if (ai_family == AF_INET6) { + type = NETCONN_DNS_IPV6; + } +#endif /* LWIP_IPV4 && LWIP_IPV6 */ + err = netconn_gethostbyname_addrtype(nodename, &addr, type); + if (err != ERR_OK) { + return EAI_FAIL; + } + } + } else { + /* service location specified, use loopback address */ + if ((hints != NULL) && (hints->ai_flags & AI_PASSIVE)) { + ip_addr_set_any_val(ai_family == AF_INET6, addr); + } else { + ip_addr_set_loopback_val(ai_family == AF_INET6, addr); + } + } + + total_size = sizeof(struct addrinfo) + sizeof(struct sockaddr_storage); + if (nodename != NULL) { + namelen = strlen(nodename); + if (namelen > DNS_MAX_NAME_LENGTH) { + /* invalid name length */ + return EAI_FAIL; + } + LWIP_ASSERT("namelen is too long", total_size + namelen + 1 > total_size); + total_size += namelen + 1; + } + /* If this fails, please report to lwip-devel! :-) */ + LWIP_ASSERT("total_size <= NETDB_ELEM_SIZE: please report this!", + total_size <= NETDB_ELEM_SIZE); + ai = (struct addrinfo *)memp_malloc(MEMP_NETDB); + if (ai == NULL) { + return EAI_MEMORY; + } + memset(ai, 0, total_size); + /* cast through void* to get rid of alignment warnings */ + sa = (struct sockaddr_storage *)(void *)((u8_t *)ai + sizeof(struct addrinfo)); + if (IP_IS_V6_VAL(addr)) { +#if LWIP_IPV6 + struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa; + /* set up sockaddr */ + inet6_addr_from_ip6addr(&sa6->sin6_addr, ip_2_ip6(&addr)); + sa6->sin6_family = AF_INET6; + sa6->sin6_len = sizeof(struct sockaddr_in6); + sa6->sin6_port = lwip_htons((u16_t)port_nr); + sa6->sin6_scope_id = ip6_addr_zone(ip_2_ip6(&addr)); + ai->ai_family = AF_INET6; +#endif /* LWIP_IPV6 */ + } else { +#if LWIP_IPV4 + struct sockaddr_in *sa4 = (struct sockaddr_in *)sa; + /* set up sockaddr */ + inet_addr_from_ip4addr(&sa4->sin_addr, ip_2_ip4(&addr)); + sa4->sin_family = AF_INET; + sa4->sin_len = sizeof(struct sockaddr_in); + sa4->sin_port = lwip_htons((u16_t)port_nr); + ai->ai_family = AF_INET; +#endif /* LWIP_IPV4 */ + } + + /* set up addrinfo */ + if (hints != NULL) { + /* copy socktype & protocol from hints if specified */ + ai->ai_socktype = hints->ai_socktype; + ai->ai_protocol = hints->ai_protocol; + } + if (nodename != NULL) { + /* copy nodename to canonname if specified */ + ai->ai_canonname = ((char *)ai + sizeof(struct addrinfo) + sizeof(struct sockaddr_storage)); + MEMCPY(ai->ai_canonname, nodename, namelen); + ai->ai_canonname[namelen] = 0; + } + ai->ai_addrlen = sizeof(struct sockaddr_storage); + ai->ai_addr = (struct sockaddr *)sa; + + *res = ai; + + return 0; +} + +int +getnameinfo(const struct sockaddr *sa, socklen_t salen, char *node, + size_t nodelen, char *service, size_t servicelen, int flags) +{ + int af; + const struct sockaddr_in *sa_in = (const struct sockaddr_in *)sa; + + (void) salen; + + af = sa->sa_family; + if (af != AF_INET) { + return EAI_FAMILY; + } + + if ((flags & NI_NAMEREQD) != 0) { + return EAI_NONAME; + } + + /* FIXME: This return just the address value. Try resolving instead. */ + if (node != NULL && nodelen > 0) { + if (inet_ntop(af, &sa_in->sin_addr, node, nodelen) == NULL) { + return EAI_FAIL; + } + } + + if (service != NULL && servicelen > 0) { + in_port_t port = ntohs(sa_in->sin_port); + int rv; + + rv = snprintf(service, servicelen, "%u", port); + if (rv <= 0) { + return EAI_FAIL; + } else if ((unsigned)rv >= servicelen) { + return EAI_OVERFLOW; + } + } + + return 0; +} + +#endif /* LWIP_DNS && LWIP_SOCKET */ |