| /** |
| * @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/memp.h" |
| #include "lwip/ip_addr.h" |
| #include "lwip/api.h" |
| #include "lwip/dns.h" |
| |
| #include <string.h> |
| #include <stdlib.h> |
| |
| /** 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]; |
| |
| /* 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; |
| s_hostent.h_name = (char*)name; |
| 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", 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]-> == %p\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 == %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", 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, ip_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) + 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 = 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 |
| */ |
| 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_in *sa = NULL; |
| int port_nr = 0; |
| size_t total_size; |
| size_t namelen = 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 */ |
| ip_addr_set_loopback(&addr); |
| } |
| |
| total_size = sizeof(struct addrinfo) + sizeof(struct sockaddr_in); |
| if (nodename != NULL) { |
| namelen = strlen(nodename); |
| LWIP_ASSERT("namelen is too long", (namelen + 1) <= (mem_size_t)-1); |
| 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) { |
| goto memerr; |
| } |
| memset(ai, 0, total_size); |
| sa = (struct sockaddr_in*)((u8_t*)ai + sizeof(struct addrinfo)); |
| /* set up sockaddr */ |
| inet_addr_from_ipaddr(&sa->sin_addr, &addr); |
| sa->sin_family = AF_INET; |
| sa->sin_len = sizeof(struct sockaddr_in); |
| sa->sin_port = htons((u16_t)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 */ |
| ai->ai_canonname = ((char*)ai + sizeof(struct addrinfo) + sizeof(struct sockaddr_in)); |
| 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) { |
| memp_free(MEMP_NETDB, ai); |
| } |
| return EAI_MEMORY; |
| } |
| |
| #endif /* LWIP_DNS && LWIP_SOCKET */ |