--- /dev/null
+/**
+ * @file
+ * API functions for name resolving
+ *
+ */
+
+/*
+ * 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/ip_addr.h"
+#include "lwip/api.h"
+
+/** helper struct for gethostbyname_r to access the char* buffer */
+struct gethostbyname_r_helper {
+ struct ip_addr *addrs;
+ struct ip_addr 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;
+ struct ip_addr addr;
+
+ /* buffer variables for lwip_gethostbyname() */
+ HOSTENT_STORAGE struct hostent s_hostent;
+ HOSTENT_STORAGE char *s_aliases;
+ HOSTENT_STORAGE struct ip_addr s_hostent_addr;
+ HOSTENT_STORAGE struct ip_addr *s_phostent_addr;
+
+ /* 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 = &s_hostent_addr;
+ s_hostent.h_name = (char*)name;
+ s_hostent.h_aliases = &s_aliases;
+ s_hostent.h_addrtype = AF_INET;
+ s_hostent.h_length = sizeof(struct ip_addr);
+ 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 == 0x%08lX\n",(u32_t)(s_hostent.h_aliases)));
+ if (s_hostent.h_aliases != NULL) {
+ u8_t idx;
+ for ( idx=0; s_hostent.h_aliases[idx]; idx++) {
+ LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_aliases[%i]-> == 0x%08lX\n", idx, s_hostent.h_aliases[idx]));
+ LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_aliases[%i]-> == %s\n", idx, s_hostent.h_aliases[idx]));
+ }
+ }
+ LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addrtype == %lu\n", (u32_t)(s_hostent.h_addrtype)));
+ LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_length == %lu\n", (u32_t)(s_hostent.h_length)));
+ LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list == 0x%08lX\n", 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] == 0x%08lX\n", idx, s_hostent.h_addr_list[idx]));
+ LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list[%i]-> == %s\n", idx, inet_ntoa(*((struct in_addr*)(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 == 0)) {
+ /* not all arguments given */
+ *h_errnop = EINVAL;
+ return -1;
+ }
+
+ namelen = strlen(name);
+ if (buflen < (sizeof(struct gethostbyname_r_helper) + namelen + 1 + (MEM_ALIGNMENT - 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 = ENSRNOTFOUND;
+ return -1;
+ }
+
+ /* copy the hostname into buf */
+ MEMCPY(hostname, name, namelen);
+ hostname[namelen] = 0;
+
+ /* fill hostent */
+ h->addrs = &(h->addr);
+ h->aliases = NULL;
+ ret->h_name = (char*)hostname;
+ ret->h_aliases = &(h->aliases);
+ ret->h_addrtype = AF_INET;
+ ret->h_length = sizeof(struct ip_addr);
+ ret->h_addr_list = (char**)&(h->addrs);
+
+ /* 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) {
+ if (ai->ai_addr != NULL) {
+ mem_free(ai->ai_addr);
+ }
+ if (ai->ai_canonname != NULL) {
+ mem_free(ai->ai_canonname);
+ }
+ next = ai->ai_next;
+ mem_free(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
+ */
+int
+lwip_getaddrinfo(const char *nodename, const char *servname,
+ const struct addrinfo *hints, struct addrinfo **res)
+{
+ err_t err;
+ struct ip_addr addr;
+ struct addrinfo *ai;
+ struct sockaddr_in *sa = NULL;
+ int port_nr = 0;
+
+ if (res == NULL) {
+ return EAI_FAIL;
+ }
+ *res = NULL;
+ if ((nodename == NULL) && (servname == NULL)) {
+ return EAI_NONAME;
+ }
+
+ if (servname != NULL) {
+ /* service name specified: convert to port number
+ * @todo?: currently, only ASCII integers (port numbers) are supported! */
+ port_nr = atoi(servname);
+ if ((port_nr <= 0) || (port_nr > 0xffff)) {
+ return EAI_SERVICE;
+ }
+ }
+
+ if (nodename != NULL) {
+ /* service location specified, try to resolve */
+ err = netconn_gethostbyname(nodename, &addr);
+ if (err != ERR_OK) {
+ return EAI_FAIL;
+ }
+ } else {
+ /* service location specified, use loopback address */
+ addr.addr = INADDR_LOOPBACK;
+ }
+
+ ai = mem_malloc(sizeof(struct addrinfo));
+ if (ai == NULL) {
+ goto memerr;
+ }
+ memset(ai, 0, sizeof(struct addrinfo));
+ sa = mem_malloc(sizeof(struct sockaddr_in));
+ if (sa == NULL) {
+ goto memerr;
+ }
+ memset(sa, 0, sizeof(struct sockaddr_in));
+ /* set up sockaddr */
+ sa->sin_addr.s_addr = addr.addr;
+ sa->sin_family = AF_INET;
+ sa->sin_len = sizeof(struct sockaddr_in);
+ sa->sin_port = htons(port_nr);
+
+ /* set up addrinfo */
+ ai->ai_family = AF_INET;
+ 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 */
+ size_t namelen = strlen(nodename);
+ ai->ai_canonname = mem_malloc(namelen + 1);
+ if (ai->ai_canonname == NULL) {
+ goto memerr;
+ }
+ MEMCPY(ai->ai_canonname, nodename, namelen);
+ ai->ai_canonname[namelen] = 0;
+ }
+ ai->ai_addrlen = sizeof(struct sockaddr_in);
+ ai->ai_addr = (struct sockaddr*)sa;
+
+ *res = ai;
+
+ return 0;
+memerr:
+ if (ai != NULL) {
+ mem_free(ai);
+ }
+ if (sa != NULL) {
+ mem_free(sa);
+ }
+ return EAI_MEMORY;
+}
+
+#endif /* LWIP_DNS && LWIP_SOCKET */
