From c79a94df7996ad23d5ae899b89d9153053e281ed Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Mon, 26 Jul 2010 23:40:53 -0700 Subject: Add better result callback handling for resolver library --- gresolv/gresolv.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++---- gresolv/gresolv.h | 11 +++++- 2 files changed, 107 insertions(+), 7 deletions(-) diff --git a/gresolv/gresolv.c b/gresolv/gresolv.c index 8256b0b7..40bde542 100644 --- a/gresolv/gresolv.c +++ b/gresolv/gresolv.c @@ -34,6 +34,15 @@ #include "gresolv.h" +struct resolv_query { + guint id; + + uint16_t msgid; + + GResolvResultFunc result_func; + gpointer result_data; +}; + struct resolv_nameserver { GResolv *resolv; @@ -48,6 +57,9 @@ struct resolv_nameserver { struct _GResolv { gint ref_count; + guint next_query_id; + GQueue *query_queue; + int index; GList *nameserver_list; @@ -71,6 +83,11 @@ static inline void debug(GResolv *resolv, const char *format, ...) va_end(ap); } +static void destroy_query(struct resolv_query *query) +{ + g_free(query); +} + static void free_nameserver(struct resolv_nameserver *nameserver) { if (nameserver == NULL) @@ -121,24 +138,45 @@ static int send_query(GResolv *resolv, const unsigned char *buf, int len) return 0; } +static gint compare_msgid(gconstpointer a, gconstpointer b) +{ + const struct resolv_query *query = a; + uint16_t msgid = GPOINTER_TO_UINT(b); + + if (query->msgid < msgid) + return -1; + + if (query->msgid > msgid) + return 1; + + return 0; +} + static void parse_response(struct resolv_nameserver *nameserver, const unsigned char *buf, int len) { GResolv *resolv = nameserver->resolv; + GList *list; + char **results; ns_msg msg; ns_rr rr; - int i, rcode; + int i, n, rcode, count; debug(resolv, "response from %s", nameserver->address); ns_initparse(buf, len, &msg); rcode = ns_msg_getflag(msg, ns_f_rcode); + count = ns_msg_count(msg, ns_s_an); debug(resolv, "msg id: 0x%04x rcode: %d count: %d", - ns_msg_id(msg), rcode, ns_msg_count(msg, ns_s_an)); + ns_msg_id(msg), rcode, count); + + results = g_try_new(char *, count + 1); + if (results == NULL) + return; - for (i = 0; i < ns_msg_count(msg, ns_s_an); i++) { + for (i = 0, n = 0; i < count; i++) { char result[100]; ns_parserr(&msg, ns_s_an, i, &rr); @@ -154,8 +192,26 @@ static void parse_response(struct resolv_nameserver *nameserver, inet_ntop(AF_INET, ns_rr_rdata(rr), result, sizeof(result)); - debug(resolv, "result: %s", result); + results[n++] = g_strdup(result); + } + + results[n] = NULL; + + list = g_queue_find_custom(resolv->query_queue, + GUINT_TO_POINTER(ns_msg_id(msg)), compare_msgid); + + if (list != NULL) { + struct resolv_query *query = list->data; + + if (query->result_func != NULL) + query->result_func(G_RESOLV_STATUS_SUCCESS, + results, query->result_data); + + destroy_query(query); + g_queue_remove(resolv->query_queue, query); } + + g_strfreev(results); } static gboolean received_udp_data(GIOChannel *channel, GIOCondition cond, @@ -228,6 +284,14 @@ GResolv *g_resolv_new(int index) resolv->ref_count = 1; + resolv->next_query_id = 1; + resolv->query_queue = g_queue_new(); + + if (resolv->query_queue == NULL) { + g_free(resolv); + return NULL; + } + resolv->index = index; resolv->nameserver_list = NULL; @@ -246,12 +310,19 @@ GResolv *g_resolv_ref(GResolv *resolv) void g_resolv_unref(GResolv *resolv) { + struct resolv_query *query; + if (resolv == NULL) return; if (g_atomic_int_dec_and_test(&resolv->ref_count) == FALSE) return; + while ((query = g_queue_pop_head(resolv->query_queue))) + destroy_query(query); + + g_queue_free(resolv->query_queue); + flush_nameservers(resolv); g_free(resolv); @@ -306,18 +377,38 @@ void g_resolv_flush_nameservers(GResolv *resolv) flush_nameservers(resolv); } -int g_resolv_lookup_hostname(GResolv *resolv, const char *hostname) +guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname, + GResolvResultFunc func, gpointer user_data) { + struct resolv_query *query; unsigned char buf[4096]; int len; debug(resolv, "lookup hostname %s", hostname); + if (resolv == NULL) + return 0; + + query = g_try_new0(struct resolv_query, 1); + if (query == NULL) + return 0; + + query->id = resolv->next_query_id++; + len = res_mkquery(ns_o_query, hostname, ns_c_in, ns_t_a, NULL, 0, NULL, buf, sizeof(buf)); - if (send_query(resolv, buf, len) < 0) + query->msgid = buf[0] << 8 | buf[1]; + + query->result_func = func; + query->result_data = user_data; + + if (send_query(resolv, buf, len) < 0) { + g_free(query); return -EIO; + } + + g_queue_push_tail(resolv->query_queue, query); return 0; } diff --git a/gresolv/gresolv.h b/gresolv/gresolv.h index baafd355..1d0b3c1b 100644 --- a/gresolv/gresolv.h +++ b/gresolv/gresolv.h @@ -34,6 +34,14 @@ struct _GResolv; typedef struct _GResolv GResolv; +typedef enum { + G_RESOLV_STATUS_SUCCESS, + G_RESOLV_STATUS_ERROR, +} GResolvResultStatus; + +typedef void (*GResolvResultFunc)(GResolvResultStatus status, + char **results, gpointer user_data); + typedef void (*GResolvDebugFunc)(const char *str, gpointer user_data); GResolv *g_resolv_new(int index); @@ -48,7 +56,8 @@ int g_resolv_add_nameserver(GResolv *resolv, const char *address, uint16_t port, unsigned long flags); void g_resolv_flush_nameservers(GResolv *resolv); -int g_resolv_lookup_hostname(GResolv *resolv, const char *hostname); +guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname, + GResolvResultFunc func, gpointer user_data); #ifdef __cplusplus } -- cgit v1.2.3