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[/] [openrisc/] [trunk/] [rtos/] [ecos-2.0/] [packages/] [redboot/] [v2_0/] [src/] [net/] [dns.c] - Rev 256
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//============================================================================= // // dns.c // // DNS client code // //============================================================================= //####ECOSGPLCOPYRIGHTBEGIN#### // ------------------------------------------- // This file is part of eCos, the Embedded Configurable Operating System. // Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc. // // eCos is free software; you can redistribute it and/or modify it under // the terms of the GNU General Public License as published by the Free // Software Foundation; either version 2 or (at your option) any later version. // // eCos is distributed in the hope that it will be useful, but WITHOUT ANY // WARRANTY; without even the implied warranty of MERCHANTABILITY or // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License // for more details. // // You should have received a copy of the GNU General Public License along // with eCos; if not, write to the Free Software Foundation, Inc., // 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. // // As a special exception, if other files instantiate templates or use macros // or inline functions from this file, or you compile this file and link it // with other works to produce a work based on this file, this file does not // by itself cause the resulting work to be covered by the GNU General Public // License. However the source code for this file must still be made available // in accordance with section (3) of the GNU General Public License. // // This exception does not invalidate any other reasons why a work based on // this file might be covered by the GNU General Public License. // // Alternative licenses for eCos may be arranged by contacting Red Hat, Inc. // at http://sources.redhat.com/ecos/ecos-license/ // ------------------------------------------- //####ECOSGPLCOPYRIGHTEND#### //============================================================================= //#####DESCRIPTIONBEGIN#### // // Author(s): jskov // Contributors:jskov // Date: 2001-09-26 // Description: Provides DNS lookup as per RFC 1034/1035. // // Note: This is a stripped down clone of dns.c from the CYGPKG_NS_DNS // package which does not use malloc/free and has been tweaked to // use UDP via RedBoot's network stack. Also adds commands // to set the DNS server IP at runtime. // //####DESCRIPTIONEND#### // //============================================================================= #include <cyg/hal/drv_api.h> #include <cyg/infra/cyg_type.h> #include <cyg/infra/cyg_trac.h> /* Tracing support */ #include <net/net.h> #include <redboot.h> /* #include <cyg/ns/dns/dns.h> - it's been moved to redboot.h */ #include <cyg/ns/dns/dns_priv.h> #ifdef CYGSEM_REDBOOT_FLASH_CONFIG #include <flash_config.h> RedBoot_config_option("DNS server IP address", dns_ip, ALWAYS_ENABLED, true, CONFIG_IP, 0 ); #endif /* So we remember which ports have been used */ static int get_port = 7700; #define DOMAIN_PORT 53 /* Some magic to make dns_impl.inl compile under RedBoot */ #define sprintf diag_sprintf struct sockaddr_in server; /* static buffers so we can make do without malloc */ static struct hostent _hent; static char* _h_addr_list[2]; static struct in_addr _h_addr_list0; static int _hent_alloc = 0; #define _STRING_COUNT 2 #define _STRING_LENGTH 64 static char _strings[_STRING_COUNT][_STRING_LENGTH]; static int _strings_alloc = 0; /* as in dns.c proper */ static short id = 0; /* ID of the last query */ static int s = -1; /* Socket to the DNS server */ static cyg_drv_mutex_t dns_mutex; /* Mutex to stop multiple queries as once */ static char * domainname=NULL; /* Domain name used for queries */ /* Allocate space for string of length (len). Return NULL on failure. */ static char* alloc_string(int len) { int i; if (len > _STRING_LENGTH) return NULL; for (i = 0; i < _STRING_COUNT; i++) { if (_strings_alloc & (1 << i)) continue; _strings_alloc |= (1<<i); return _strings[i]; } return NULL; } static void free_string(char* s) { int i; for (i = 0; i < _STRING_COUNT; i++) { if (_strings[i] == s) { _strings_alloc &= ~(1<<i); break; } } } /* Deallocate the memory taken to hold a hent structure */ static void free_hent(struct hostent * hent) { if (hent->h_name) { free_string(hent->h_name); } _hent_alloc = 0; } /* Allocate hent structure with room for one in_addr. Returns NULL on failure. */ static struct hostent* alloc_hent(void) { struct hostent *hent; if (_hent_alloc) return NULL; hent = &_hent; memset(hent, 0, sizeof(struct hostent)); hent->h_addr_list = _h_addr_list; hent->h_addr_list[0] = (char*)&_h_addr_list0; hent->h_addr_list[1] = NULL; _hent_alloc = 1; return hent; } static __inline__ void free_stored_hent(void) { free_hent( &_hent ); } static __inline__ void store_hent(struct hostent *hent) { hent=hent; // avoid warning } /* Send the query to the server and read the response back. Return -1 if it fails, otherwise put the response back in msg and return the length of the response. */ static int send_recv(char * msg, int len, int msglen) { struct dns_header *dns_hdr; int finished = false; int read = 0; dns_hdr = (struct dns_header *) msg; do { int len_togo = len; struct timeval timeout; struct sockaddr_in local_addr, from_addr; memset((char *)&local_addr, 0, sizeof(local_addr)); local_addr.sin_family = AF_INET; local_addr.sin_addr.s_addr = htonl(INADDR_ANY); local_addr.sin_port = htons(get_port++); if (__udp_sendto(msg, len_togo, &server, &local_addr) < 0) return -1; memset((char *)&from_addr, 0, sizeof(from_addr)); timeout.tv_sec = CYGNUM_REDBOOT_NETWORKING_DNS_TIMEOUT; timeout.tv_usec = 0; read = __udp_recvfrom(msg, len, &from_addr, &local_addr, &timeout); if (read < 0) return -1; /* Reply to an old query. Ignore it */ if (ntohs(dns_hdr->id) != (id-1)) { continue; } finished = true; } while (!finished); return read; } void set_dns(char* new_ip) { in_addr_t dns_ip; memset(&server.sin_addr, 0, sizeof(server.sin_addr)); if (!inet_aton(new_ip, &dns_ip)) { diag_printf("Bad DNS server address: %s\n", new_ip); } else { memcpy(&server.sin_addr, &dns_ip, sizeof(dns_ip)); /* server config is valid */ s = 0; } } void show_dns(void) { diag_printf(", DNS server IP: %s", inet_ntoa((in_addr_t *)&server.sin_addr)); if (0 == server.sin_addr.s_addr) { s = -1; } } /* Initialise the resolver. Open a socket and bind it to the address of the server. return -1 if something goes wrong, otherwise 0 */ int redboot_dns_res_init(void) { memset((char *)&server, 0, sizeof(server)); server.sin_len = sizeof(server); server.sin_family = AF_INET; server.sin_port = htons(DOMAIN_PORT); cyg_drv_mutex_init(&dns_mutex); #ifdef CYGSEM_REDBOOT_FLASH_CONFIG { ip_addr_t dns_ip; flash_get_config("dns_ip", &dns_ip, CONFIG_IP); if (dns_ip[0] == 0 && dns_ip[1] == 0 && dns_ip[2] == 0 && dns_ip[3] == 0) return -1; memcpy(&server.sin_addr, &dns_ip, sizeof(dns_ip)); /* server config is valid */ s = 0; } #else // Use static configuration set_dns(__Xstr(CYGPKG_REDBOOT_NETWORKING_DNS_IP)); #endif return 0; } /* Include the DNS client implementation code */ #include <cyg/ns/dns/dns_impl.inl>
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