diff --git a/authd/dns.c b/authd/dns.c index ddac5be42..43e69f9c2 100644 --- a/authd/dns.c +++ b/authd/dns.c @@ -1,4 +1,4 @@ -/* authd/dns.h - header for authd DNS functions +/* authd/dns.c - authd DNS functions * Copyright (c) 2016 William Pitcock * * Permission to use, copy, modify, and/or distribute this software for any @@ -22,120 +22,228 @@ #include "dns.h" #include "res.h" -static void -submit_dns_answer(void *userdata, struct DNSReply *reply) -{ - struct dns_request *req = userdata; - char response[64] = "*"; - char status = 'E'; +static void handle_lookup_ip_reply(void *data, struct DNSReply *reply); +static void handle_lookup_hostname_reply(void *data, struct DNSReply *reply); - if (reply == NULL) +uint64_t query_count = 0; + +/* A bit different from ircd... you just get a dns_query object. + * + * It gets freed whenever the res code gets back to us. + */ +struct dns_query * +lookup_ip(const char *host, int aftype, DNSCB callback, void *data) +{ + struct dns_query *query = rb_malloc(sizeof(struct dns_query)); + int g_type; + + if(aftype == AF_INET) { - rb_helper_write(authd_helper, "E %s E %c *", req->reqid, req->type); - goto cleanup; + query->type = QUERY_A; + g_type = T_A; + } +#ifdef RB_IPV6 + else if(aftype == AF_INET6) + { + query->type = QUERY_AAAA; + g_type = T_AAAA; + } +#endif + else + { + rb_free(query); + return NULL; } - switch (req->type) + query->id = query_count++; + query->callback = callback; + query->data = data; + + query->query.ptr = query; + query->query.callback = handle_lookup_ip_reply; + + gethost_byname_type(host, &query->query, g_type); + + return query; +} + +/* See lookup_ip's comment */ +struct dns_query * +lookup_hostname(const char *ip, int aftype, DNSCB callback, void *data) +{ + struct dns_query *query = rb_malloc(sizeof(struct dns_query)); + + if(!rb_inet_pton_sock(ip, (struct sockaddr *)&query->addr)) { - case '4': - if (GET_SS_FAMILY(&reply->addr) == AF_INET) - { - status = 'O'; - rb_inet_ntop_sock((struct sockaddr *) &reply->addr, response, sizeof(response)); - } - break; + rb_free(query); + return NULL; + } + + if(aftype == AF_INET) + query->type = QUERY_PTR_A; #ifdef RB_IPV6 - case '6': - if (GET_SS_FAMILY(&reply->addr) == AF_INET6) - { - char tmpres[63]; - rb_inet_ntop_sock((struct sockaddr *) &reply->addr, tmpres, sizeof(tmpres)); - - if (*tmpres == ':') - { - rb_strlcpy(response, "0", sizeof(response)); - rb_strlcat(response, tmpres, sizeof(response)); - } - else - rb_strlcpy(response, tmpres, sizeof(response)); - - status = 'O'; - } - break; + else if(aftype == AF_INET6) + query->type = QUERY_PTR_AAAA; #endif - case 'R': - { - struct sockaddr_in *ip, *ip_fwd; - ip = (struct sockaddr_in *) &req->addr; - ip_fwd = (struct sockaddr_in *) &reply->addr; + else + { + rb_free(query); + return NULL; + } - if(ip->sin_addr.s_addr == ip_fwd->sin_addr.s_addr && strlen(reply->h_name) < 63) - { - rb_strlcpy(response, reply->h_name, sizeof(response)); - status = 'O'; - } - } + query->id = query_count++; + query->callback = callback; + query->data = data; + + query->query.ptr = query; + query->query.callback = handle_lookup_hostname_reply; + + gethost_byaddr(&query->addr, &query->query); + + return query; +} + +/* Callback from gethost_byname_type */ +static void +handle_lookup_ip_reply(void *data, struct DNSReply *reply) +{ + struct dns_query *query = data; + char ip[64] = "*"; + query_type type = QUERY_INVALID; + + if(!query) + /* Shouldn't happen */ + exit(2); + + type = query->type; + + if(!reply) + goto end; + + switch(query->type) + { + case QUERY_A: + if(GET_SS_FAMILY(&reply->addr) == AF_INET) + rb_inet_ntop_sock((struct sockaddr *)&reply->addr, ip, sizeof(ip)); break; #ifdef RB_IPV6 - case 'S': + case QUERY_AAAA: + if(GET_SS_FAMILY(&reply->addr) == AF_INET6) { - struct sockaddr_in6 *ip, *ip_fwd; - ip = (struct sockaddr_in6 *) &req->addr; - ip_fwd = (struct sockaddr_in6 *) &reply->addr; - - if(memcmp(&ip->sin6_addr, &ip_fwd->sin6_addr, sizeof(struct in6_addr)) == 0 && strlen(reply->h_name) < 63) + rb_inet_ntop_sock((struct sockaddr *)&reply->addr, ip, sizeof(ip)); + if(ip[0] == ':') { - rb_strlcpy(response, reply->h_name, sizeof(response)); - status = 'O'; + memmove(&ip[1], ip, strlen(ip)); + ip[0] = '0'; } } break; #endif default: - exit(7); + exit(3); } - rb_helper_write(authd_helper, "E %s %c %c %s", req->reqid, status, req->type, response); -cleanup: - rb_free(req); +end: + if(query->callback) + query->callback(ip, ip[0] != '*', type, query->data); + + rb_free(query); +} + +/* Callback from gethost_byaddr */ +static void +handle_lookup_hostname_reply(void *data, struct DNSReply *reply) +{ + struct dns_query *query = data; + char *hostname = NULL; + query_type type = QUERY_INVALID; + + if(!query) + /* Shouldn't happen */ + exit(4); + + type = query->type; + + if(!reply) + goto end; + + if(query->type == QUERY_PTR_A) + { + struct sockaddr_in *ip, *ip_fwd; + ip = (struct sockaddr_in *) &query->addr; + ip_fwd = (struct sockaddr_in *) &reply->addr; + + if(ip->sin_addr.s_addr == ip_fwd->sin_addr.s_addr && strlen(reply->h_name) < 63) + hostname = reply->h_name; + } +#ifdef RB_IPV6 + else if(query->type == QUERY_PTR_AAAA) + { + struct sockaddr_in6 *ip, *ip_fwd; + ip = (struct sockaddr_in6 *) &query->addr; + ip_fwd = (struct sockaddr_in6 *) &reply->addr; + + if(memcmp(&ip->sin6_addr, &ip_fwd->sin6_addr, sizeof(struct in6_addr)) == 0 && strlen(reply->h_name) < 63) + hostname = reply->h_name; + } +#endif + else + /* Shouldn't happen */ + exit(5); +end: + if(query->callback) + query->callback(hostname, hostname != NULL, query->type, query->data); + + rb_free(query); +} + +static void +submit_dns_answer(const char *reply, bool status, query_type type, void *data) +{ + char *id = data; + + if(!id || type == QUERY_INVALID) + exit(6); + + if(!reply || !status) + { + rb_helper_write(authd_helper, "E %s E %c *", id, type); + rb_free(id); + } + + rb_helper_write(authd_helper, "E %s O %c %s", id, type, reply); + rb_free(id); } void resolve_dns(int parc, char *parv[]) { - struct dns_request *req; - char *requestid = parv[1]; - char *qtype = parv[2]; - char *rec = parv[3]; - int type; + char *id = rb_strdup(parv[1]); + char qtype = *parv[2]; + char *record = parv[3]; + int aftype = AF_INET; - req = rb_malloc(sizeof(*req)); - rb_strlcpy(req->reqid, requestid, sizeof(req->reqid)); - req->type = *qtype; - - switch (req->type) + switch(qtype) { - case '4': - type = T_A; - break; +#ifdef RB_IPV6 case '6': - type = T_AAAA; + aftype = AF_INET6; +#endif + case '4': + if(!lookup_ip(record, aftype, submit_dns_answer, id)) + submit_dns_answer(NULL, false, qtype, NULL); break; - case 'R': +#ifdef RB_IPV6 case 'S': - if(!rb_inet_pton_sock(rec, (struct sockaddr *) &req->addr)) - exit(6); - type = T_PTR; + aftype = AF_INET6; +#endif + case 'R': + if(!lookup_hostname(record, aftype, submit_dns_answer, id)) + submit_dns_answer(NULL, false, qtype, NULL); break; + default: + exit(7); } - - req->query.ptr = req; - req->query.callback = submit_dns_answer; - - if (type != T_PTR) - gethost_byname_type(rec, &req->query, type); - else - gethost_byaddr(&req->addr, &req->query); } void diff --git a/authd/dns.h b/authd/dns.h index 3e43520af..8957db365 100644 --- a/authd/dns.h +++ b/authd/dns.h @@ -23,17 +23,36 @@ #define DNS_REQ_IDLEN 10 +#include "stdinc.h" #include "res.h" #include "reslib.h" -struct dns_request +typedef enum +{ + QUERY_INVALID = 0, + QUERY_A = '4', + QUERY_AAAA = '6', + QUERY_PTR_A = 'R', + QUERY_PTR_AAAA = 'S', +} query_type; + +/* Similar to that in ircd */ +typedef void (*DNSCB)(const char *res, bool status, query_type type, void *data); + +struct dns_query { struct DNSQuery query; - char reqid[DNS_REQ_IDLEN]; + query_type type; struct rb_sockaddr_storage addr; - char type; + uint64_t id; + + DNSCB callback; + void *data; }; +extern struct dns_query *lookup_hostname(const char *ip, int aftype, DNSCB callback, void *data); +extern struct dns_query *lookup_ip(const char *host, int aftype, DNSCB callback, void *data); + extern void resolve_dns(int parc, char *parv[]); extern void enumerate_nameservers(const char *rid, const char letter); extern void reload_nameservers(const char letter);