diff options
Diffstat (limited to 'apps/netutils/resolv/resolv.c')
| -rw-r--r-- | apps/netutils/resolv/resolv.c | 401 |
1 files changed, 257 insertions, 144 deletions
diff --git a/apps/netutils/resolv/resolv.c b/apps/netutils/resolv/resolv.c index 5d447ee49..32bbda511 100644 --- a/apps/netutils/resolv/resolv.c +++ b/apps/netutils/resolv/resolv.c @@ -4,15 +4,10 @@ * * The uIP DNS resolver functions are used to lookup a hostname and * map it to a numerical IP address. It maintains a list of resolved - * hostnames that can be queried with the resolv_lookup() - * function. New hostnames can be resolved using the resolv_query() - * function. + * hostnames that can be queried. New hostnames can be resolved using the + * dns_whois() function. * - * When a hostname has been resolved (or found to be non-existant), - * the resolver code calls a callback function called resolv_found() - * that must be implemented by the module that uses the resolver. - * - * Copyright (C) 2007, 2009, 2012 Gregory Nutt. All rights reserved. + * Copyright (C) 2007, 2009, 2012, 2014 Gregory Nutt. All rights reserved. * Author: Gregory Nutt <gnutt@nuttx.org> * * Based heavily on portions of uIP: @@ -68,17 +63,17 @@ #include <apps/netutils/uiplib.h> /**************************************************************************** - * Definitions + * Pre-processor Definitions ****************************************************************************/ -#ifndef CONFIG_NET_RESOLV_ENTRIES -#define RESOLV_ENTRIES 4 -#else /* CONFIG_NET_RESOLV_ENTRIES */ -#define RESOLV_ENTRIES CONFIG_NET_RESOLV_ENTRIES -#endif /* CONFIG_NET_RESOLV_ENTRIES */ +#ifndef CONFIG_NETUTILS_DNSCLIENT_ENTRIES +# define RESOLV_ENTRIES 4 +#else /* CONFIG_NETUTILS_DNSCLIENT_ENTRIES */ +# define RESOLV_ENTRIES CONFIG_NETUTILS_DNSCLIENT_ENTRIES +#endif /* CONFIG_NETUTILS_DNSCLIENT_ENTRIES */ #ifndef NULL -#define NULL (void *)0 +# define NULL (void *)0 #endif /* NULL */ /* The maximum number of retries when asking for a name */ @@ -99,16 +94,16 @@ #define SEND_BUFFER_SIZE 64 -#ifdef CONFIG_NET_RESOLV_MAXRESPONSE -# define RECV_BUFFER_SIZE CONFIG_NET_RESOLV_MAXRESPONSE +#ifdef CONFIG_NETUTILS_DNSCLIENT_MAXRESPONSE +# define RECV_BUFFER_SIZE CONFIG_NETUTILS_DNSCLIENT_MAXRESPONSE #else # define RECV_BUFFER_SIZE 96 #endif #ifdef CONFIG_NET_IPv6 -#define ADDRLEN sizeof(struct sockaddr_in6) +# define ADDRLEN sizeof(struct sockaddr_in6) #else -#define ADDRLEN sizeof(struct sockaddr_in) +# define ADDRLEN sizeof(struct sockaddr_in) #endif /**************************************************************************** @@ -120,7 +115,8 @@ struct dns_hdr { uint16_t id; - uint8_t flags1, flags2; + uint8_t flags1; + uint8_t flags2; uint16_t numquestions; uint16_t numanswers; uint16_t numauthrr; @@ -177,9 +173,15 @@ static struct sockaddr_in g_dnsserver; * Private Functions ****************************************************************************/ -/* Walk through a compact encoded DNS name and return the end of it. */ +/**************************************************************************** + * Name: parse_name + * + * Description: + * Walk through a compact encoded DNS name and return the end of it. + * + ****************************************************************************/ -static unsigned char *parse_name(unsigned char *query) +static FAR unsigned char *parse_name(FAR unsigned char *query) { unsigned char n; @@ -194,29 +196,37 @@ static unsigned char *parse_name(unsigned char *query) } } while(*query != 0); + return query + 1; } -/* Runs through the list of names to see if there are any that have - * not yet been queried and, if so, sends out a query. - */ +/**************************************************************************** + * Name: send_query_socket + * + * Description: + * Runs through the list of names to see if there are any that have + * not yet been queried and, if so, sends out a query. + * + ****************************************************************************/ #ifdef CONFIG_NET_IPv6 -static int send_query_socket(int sockfd, const char *name, struct sockaddr_in6 *addr) +static int send_query_socket(int sockfd, FAR const char *name, + FAR struct sockaddr_in6 *addr) #else -static int send_query_socket(int sockfd, const char *name, struct sockaddr_in *addr) +static int send_query_socket(int sockfd, FAR const char *name, + FAR struct sockaddr_in *addr) #endif { - register struct dns_hdr *hdr; - char *query; - char *nptr; - const char *nameptr; + register FAR struct dns_hdr *hdr; + FAR char *query; + FAR char *nptr; + FAR const char *nameptr; uint8_t seqno = g_seqno++; static unsigned char endquery[] = {0, 0, 1, 0, 1}; char buffer[SEND_BUFFER_SIZE]; int n; - hdr = (struct dns_hdr*)buffer; + hdr = (FAR struct dns_hdr*)buffer; memset(hdr, 0, sizeof(struct dns_hdr)); hdr->id = htons(seqno); hdr->flags1 = DNS_FLAG1_RD; @@ -235,6 +245,7 @@ static int send_query_socket(int sockfd, const char *name, struct sockaddr_in *a *query++ = *nameptr; n++; } + *nptr = n; } while(*nameptr != 0); @@ -247,32 +258,43 @@ static int send_query_socket(int sockfd, const char *name, struct sockaddr_in *a DEBUGASSERT(((struct sockaddr *)addr)->sa_family == AF_INET); #endif - return sendto(sockfd, buffer, query + 5 - buffer, 0, (struct sockaddr*)addr, ADDRLEN); + return sendto(sockfd, buffer, query + 5 - buffer, + 0, (struct sockaddr*)addr, ADDRLEN); } +/**************************************************************************** + * Name: send_query + ****************************************************************************/ + #if 0 /* Not used */ #ifdef CONFIG_NET_IPv6 -static int send_query(const char *name, struct sockaddr_in6 *addr) +static int send_query(FAR const char *name, FAR struct sockaddr_in6 *addr) #else -static int send_query(const char *name, struct sockaddr_in *addr) +static int send_query(FAR const char *name, FAR struct sockaddr_in *addr) #endif { return send_query_socket(g_sockfd, name, addr); } #endif -/* Called when new UDP data arrives */ +/**************************************************************************** + * Name: recv_response_socket + * + * Description: + * Called when new UDP data arrives + * + ****************************************************************************/ #ifdef CONFIG_NET_IPv6 -#error "Not implemented" +# error "Not implemented" #else -int recv_response_socket(int sockfd, struct sockaddr_in *addr) +int recv_response_socket(int sockfd, FAR struct sockaddr_in *addr) #endif { - unsigned char *nameptr; + FAR unsigned char *nameptr; char buffer[RECV_BUFFER_SIZE]; - struct dns_answer *ans; - struct dns_hdr *hdr; + FAR struct dns_answer *ans; + FAR struct dns_hdr *hdr; #if 0 /* Not used */ uint8_t nquestions; #endif @@ -287,7 +309,7 @@ int recv_response_socket(int sockfd, struct sockaddr_in *addr) return ret; } - hdr = (struct dns_hdr *)buffer; + hdr = (FAR struct dns_hdr *)buffer; ndbg("ID %d\n", htons(hdr->id)); ndbg("Query %d\n", hdr->flags1 & DNS_FLAG1_RESPONSE); @@ -312,8 +334,8 @@ int recv_response_socket(int sockfd, struct sockaddr_in *addr) #endif nanswers = htons(hdr->numanswers); - /* Skip the name in the question. XXX: This should really be - * checked agains the name in the question, to be sure that they + /* Skip the name in the question. TODO: This should really be + * checked against the name in the question, to be sure that they * match. */ @@ -350,12 +372,13 @@ int recv_response_socket(int sockfd, struct sockaddr_in *addr) { /* Compressed name. */ - nameptr +=2; - ndbg("Compressed anwser\n"); + nameptr += 2; + ndbg("Compressed answer\n"); } else { /* Not compressed name. */ + nameptr = parse_name(nameptr); } @@ -367,16 +390,19 @@ int recv_response_socket(int sockfd, struct sockaddr_in *addr) /* Check for IP address type and Internet class. Others are discarded. */ - if (ans->type == HTONS(1) && ans->class == HTONS(1) && ans->len == HTONS(4)) + if (ans->type == HTONS(1) && + ans->class == HTONS(1) && + ans->len == HTONS(4)) { - ans->ipaddr.s_addr = *(uint32_t*)(nameptr+10); + ans->ipaddr.s_addr = *(FAR uint32_t *)(nameptr + 10); + ndbg("IP address %d.%d.%d.%d\n", (ans->ipaddr.s_addr ) & 0xff, (ans->ipaddr.s_addr >> 8 ) & 0xff, (ans->ipaddr.s_addr >> 16 ) & 0xff, (ans->ipaddr.s_addr >> 24 ) & 0xff); - /* XXX: we should really check that this IP address is the one + /* TODO: we should really check that this IP address is the one * we want. */ @@ -392,10 +418,14 @@ int recv_response_socket(int sockfd, struct sockaddr_in *addr) return ERROR; } +/**************************************************************************** + * Name: recv_response + ****************************************************************************/ + #ifdef CONFIG_NET_IPv6 -#error "Not implemented" +# error "Not implemented" #else -int recv_response(struct sockaddr_in *addr) +int recv_response(FAR struct sockaddr_in *addr) #endif { return recv_response_socket(g_sockfd, addr); @@ -406,14 +436,93 @@ int recv_response(struct sockaddr_in *addr) ****************************************************************************/ /**************************************************************************** - * Name: resolv_gethostip + * Name: dns_bind_sock + * + * Description: + * Initialize the DNS resolver using the caller provided socket. + * + ****************************************************************************/ + +int dns_bind_sock(FAR int *sockfd) +{ + struct timeval tv; + int ret; + + if (*sockfd >= 0) dns_free_sock(sockfd); + + *sockfd = socket(PF_INET, SOCK_DGRAM, 0); + if (*sockfd < 0) + { + return ERROR; + } + + /* Set up a receive timeout */ + + tv.tv_sec = 30; + tv.tv_usec = 0; + + ret = setsockopt(*sockfd, SOL_SOCKET, SO_RCVTIMEO, &tv, + sizeof(struct timeval)); + + if (ret < 0) + { + close(*sockfd); + *sockfd = -1; + return ERROR; + } + + return OK; +} + +/**************************************************************************** + * Name: dns_bind + * + * Description: + * Initialize the DNS resolver using an internal, share-able socket. + * + ****************************************************************************/ + +int dns_bind(void) +{ + return dns_bind_sock(&g_sockfd); +} + +/**************************************************************************** + * Name: dns_free_sock + * + * Description: + * Release the DNS resolver by closing the socket. + * ****************************************************************************/ -int resolv_gethostip_socket(int sockfd, const char *hostname, in_addr_t *ipaddr) +int dns_free_sock(FAR int *sockfd) +{ + if (*sockfd >= 0) + { + close(*sockfd); + *sockfd = -1; + } + + return OK; +} + +/**************************************************************************** + * Name: dns_query_sock + * + * Description: + * Using the DNS resolver socket (sockfd), look up the the 'hostname', and + * return its IP address in 'ipaddr' + * + * Returned Value: + * Returns zero (OK) if the query was successful. + * + ****************************************************************************/ + +int dns_query_sock(int sockfd, FAR const char *hostname, FAR in_addr_t *ipaddr) { #ifdef CONFIG_HAVE_GETHOSTBYNAME - struct hostent *he; + FAR struct hostent *he; nvdbg("Getting address of %s\n", hostname); he = gethostbyname(hostname); @@ -445,7 +554,7 @@ int resolv_gethostip_socket(int sockfd, const char *hostname, in_addr_t *ipaddr) * the host name to an IP address. */ - if (resolv_query_socket(sockfd, hostname, &addr) < 0) + if (dns_whois_socket(sockfd, hostname, &addr) < 0) { /* Needs to set the errno here */ @@ -456,37 +565,86 @@ int resolv_gethostip_socket(int sockfd, const char *hostname, in_addr_t *ipaddr) *ipaddr = addr.sin_addr.s_addr; } - return OK; + return OK; #endif } -int resolv_gethostip(const char *hostname, in_addr_t *ipaddr) +/**************************************************************************** + * Name: dns_query + * + * Description: + * Using the internal DNS resolver socket, look up the the 'hostname', and + * return its IP address in 'ipaddr' + * + * Returned Value: + * Returns zero (OK) if the query was successful. + * + ****************************************************************************/ + +int dns_query(FAR const char *hostname, FAR in_addr_t *ipaddr) { - return resolv_gethostip_socket(g_sockfd, hostname, ipaddr); + return dns_query_sock(g_sockfd, hostname, ipaddr); } -int dns_gethostip(const char *hostname, in_addr_t *ipaddr) +/**************************************************************************** + * Name: dns_setserver + * + * Description: + * Configure which DNS server to use for queries + * + ****************************************************************************/ + +#ifdef CONFIG_NET_IPv6 +void dns_setserver(FAR const struct in6_addr *dnsserver) +#else +void dns_setserver(FAR const struct in_addr *dnsserver) +#endif { - int sockfd = -1; - int ret=ERROR; + g_dnsserver.sin_family = AF_INET; + g_dnsserver.sin_port = HTONS(53); +#ifdef CONFIG_NET_IPv6 + memcpy(&g_dnsserver.sin6_addr, dnsserver, ADDRLEN); +#else + g_dnsserver.sin_addr.s_addr = dnsserver->s_addr; +#endif +} - resolv_create(&sockfd); - if (sockfd >= 0) - { - ret = resolv_gethostip_socket(sockfd, hostname, ipaddr); - resolv_release(&sockfd); - } +/**************************************************************************** + * Name: dns_getserver + * + * Description: + * Obtain the currently configured DNS server. + * + ****************************************************************************/ - return ret; +#ifdef CONFIG_NET_IPv6 +void dns_getserver(FAR struct in6_addr *dnsserver) +#else +void dns_getserver(FAR struct in_addr *dnsserver) +#endif +{ +#ifdef CONFIG_NET_IPv6 + memcpy(dnsserver, &g_dnsserver.sin6_addr, ADDRLEN); +#else + dnsserver->s_addr = g_dnsserver.sin_addr.s_addr; +#endif } -/* Get the binding for name. */ +/**************************************************************************** + * Name: dns_whois_socket + * + * Description: + * Get the binding for 'name' using the DNS server accessed via 'sockfd' + * + ****************************************************************************/ #ifdef CONFIG_NET_IPv6 -int resolv_query_socket(int sockfd, FAR const char *name, FAR struct sockaddr_in6 *addr) +int dns_whois_socket(int sockfd, FAR const char *name, + FAR struct sockaddr_in6 *addr) #else -int resolv_query_socket(int sockfd, FAR const char *name, FAR struct sockaddr_in *addr) +int dns_whois_socket(int sockfd, FAR const char *name, + FAR struct sockaddr_in *addr) #endif { int retries; @@ -520,91 +678,46 @@ int resolv_query_socket(int sockfd, FAR const char *name, FAR struct sockaddr_in return ERROR; } -#ifdef CONFIG_NET_IPv6 -int resolv_query(FAR const char *name, FAR struct sockaddr_in6 *addr) -#else -int resolv_query(FAR const char *name, FAR struct sockaddr_in *addr) -#endif -{ - return resolv_query_socket(g_sockfd, name, addr); -} - -/* Obtain the currently configured DNS server. */ - -#ifdef CONFIG_NET_IPv6 -void resolv_getserver(struct in6_addr *dnsserver) -#else -void resolv_getserver(struct in_addr *dnsserver) -#endif -{ -#ifdef CONFIG_NET_IPv6 - memcpy(dnsserver, &g_dnsserver.sin6_addr, ADDRLEN); -#else - dnsserver->s_addr = g_dnsserver.sin_addr.s_addr; -#endif -} - -/* Configure which DNS server to use for queries */ +/**************************************************************************** + * Name: dns_whois + * + * Description: + * Get the binding for 'name' using the DNS server accessed via the DNS + * resolvers internal socket. + * + ****************************************************************************/ #ifdef CONFIG_NET_IPv6 -void resolv_conf(const struct in6_addr *dnsserver) -#else -void resolv_conf(const struct in_addr *dnsserver) -#endif -{ - g_dnsserver.sin_family = AF_INET; - g_dnsserver.sin_port = HTONS(53); -#ifdef CONFIG_NET_IPv6 - memcpy(&g_dnsserver.sin6_addr, dnsserver, ADDRLEN); +int dns_whois(FAR const char *name, FAR struct sockaddr_in6 *addr) #else - g_dnsserver.sin_addr.s_addr = dnsserver->s_addr; +int dns_whois(FAR const char *name, FAR struct sockaddr_in *addr) #endif -} - -/* Release the resolver. */ - -int resolv_release(int *sockfd) { - if (*sockfd >= 0) - { - close(*sockfd); - *sockfd = -1; - } - - return OK; + return dns_whois_socket(g_sockfd, name, addr); } -/* Create the resolver. */ +/**************************************************************************** + * Name: dns_gethostip + * + * Descriptions: + * Combines the operations of dns_bind_sock(), dns_query_sock(), and + * dns_free_sock() to obtain the the IP address ('ipaddr') associated with + * the 'hostname' in one operation. + * + ****************************************************************************/ -int resolv_create(int *sockfd) +int dns_gethostip(FAR const char *hostname, FAR in_addr_t *ipaddr) { - struct timeval tv; - - if (*sockfd >= 0) resolv_release(sockfd); - - *sockfd = socket(PF_INET, SOCK_DGRAM, 0); - if (*sockfd < 0) - { - return ERROR; - } - - /* Set up a receive timeout */ + int sockfd = -1; + int ret=ERROR; - tv.tv_sec = 30; - tv.tv_usec = 0; - if (setsockopt(*sockfd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(struct timeval)) < 0) + dns_bind_sock(&sockfd); + if (sockfd >= 0) { - close(*sockfd); - *sockfd = -1; - return ERROR; + ret = dns_query_sock(sockfd, hostname, ipaddr); + dns_free_sock(&sockfd); } - return OK; + return ret; } -/* Initalize the resolver. */ - -int resolv_init(void) -{ - return resolv_create(&g_sockfd); -} |