diff options
author | Daniel Stenberg <daniel@haxx.se> | 2010-03-24 10:34:30 +0100 |
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committer | Daniel Stenberg <daniel@haxx.se> | 2010-03-24 10:34:30 +0100 |
commit | 4259d2df7dd95637a4b1e3fb174fe5e5aef81069 (patch) | |
tree | 8abd5ab61fbacf160f9084a44613fcc4b20e8483 /ares/ares_search.c | |
parent | 4b351d018e3d6691191fd653a17f14f4a31e0b4c (diff) |
remove the ares subtree
c-ares is now hosted entirely separate from the curl project
see http://c-ares.haxx.se/ for all details concerning c-ares,
its source repository and more.
Diffstat (limited to 'ares/ares_search.c')
-rw-r--r-- | ares/ares_search.c | 323 |
1 files changed, 0 insertions, 323 deletions
diff --git a/ares/ares_search.c b/ares/ares_search.c deleted file mode 100644 index 8673c289f..000000000 --- a/ares/ares_search.c +++ /dev/null @@ -1,323 +0,0 @@ -/* $Id$ */ - -/* Copyright 1998 by the Massachusetts Institute of Technology. - * - * Permission to use, copy, modify, and distribute this - * software and its documentation for any purpose and without - * fee is hereby granted, provided that the above copyright - * notice appear in all copies and that both that copyright - * notice and this permission notice appear in supporting - * documentation, and that the name of M.I.T. not be used in - * advertising or publicity pertaining to distribution of the - * software without specific, written prior permission. - * M.I.T. makes no representations about the suitability of - * this software for any purpose. It is provided "as is" - * without express or implied warranty. - */ - -#include "ares_setup.h" - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <ctype.h> -#include <errno.h> - -#ifdef HAVE_STRINGS_H -# include <strings.h> -#endif - -#include "ares.h" -#include "ares_private.h" - -struct search_query { - /* Arguments passed to ares_search */ - ares_channel channel; - char *name; /* copied into an allocated buffer */ - int dnsclass; - int type; - ares_callback callback; - void *arg; - - int status_as_is; /* error status from trying as-is */ - int next_domain; /* next search domain to try */ - int trying_as_is; /* current query is for name as-is */ - int timeouts; /* number of timeouts we saw for this request */ - int ever_got_nodata; /* did we ever get ARES_ENODATA along the way? */ -}; - -static void search_callback(void *arg, int status, int timeouts, - unsigned char *abuf, int alen); -static void end_squery(struct search_query *squery, int status, - unsigned char *abuf, int alen); -static int cat_domain(const char *name, const char *domain, char **s); -static int single_domain(ares_channel channel, const char *name, char **s); - -void ares_search(ares_channel channel, const char *name, int dnsclass, - int type, ares_callback callback, void *arg) -{ - struct search_query *squery; - char *s; - const char *p; - int status, ndots; - - /* If name only yields one domain to search, then we don't have - * to keep extra state, so just do an ares_query(). - */ - status = single_domain(channel, name, &s); - if (status != ARES_SUCCESS) - { - callback(arg, status, 0, NULL, 0); - return; - } - if (s) - { - ares_query(channel, s, dnsclass, type, callback, arg); - free(s); - return; - } - - /* Allocate a search_query structure to hold the state necessary for - * doing multiple lookups. - */ - squery = malloc(sizeof(struct search_query)); - if (!squery) - { - callback(arg, ARES_ENOMEM, 0, NULL, 0); - return; - } - squery->channel = channel; - squery->name = strdup(name); - if (!squery->name) - { - free(squery); - callback(arg, ARES_ENOMEM, 0, NULL, 0); - return; - } - squery->dnsclass = dnsclass; - squery->type = type; - squery->status_as_is = -1; - squery->callback = callback; - squery->arg = arg; - squery->timeouts = 0; - squery->ever_got_nodata = 0; - - /* Count the number of dots in name. */ - ndots = 0; - for (p = name; *p; p++) - { - if (*p == '.') - ndots++; - } - - /* If ndots is at least the channel ndots threshold (usually 1), - * then we try the name as-is first. Otherwise, we try the name - * as-is last. - */ - if (ndots >= channel->ndots) - { - /* Try the name as-is first. */ - squery->next_domain = 0; - squery->trying_as_is = 1; - ares_query(channel, name, dnsclass, type, search_callback, squery); - } - else - { - /* Try the name as-is last; start with the first search domain. */ - squery->next_domain = 1; - squery->trying_as_is = 0; - status = cat_domain(name, channel->domains[0], &s); - if (status == ARES_SUCCESS) - { - ares_query(channel, s, dnsclass, type, search_callback, squery); - free(s); - } - else - { - /* failed, free the malloc()ed memory */ - free(squery->name); - free(squery); - callback(arg, status, 0, NULL, 0); - } - } -} - -static void search_callback(void *arg, int status, int timeouts, - unsigned char *abuf, int alen) -{ - struct search_query *squery = (struct search_query *) arg; - ares_channel channel = squery->channel; - char *s; - - squery->timeouts += timeouts; - - /* Stop searching unless we got a non-fatal error. */ - if (status != ARES_ENODATA && status != ARES_ESERVFAIL - && status != ARES_ENOTFOUND) - end_squery(squery, status, abuf, alen); - else - { - /* Save the status if we were trying as-is. */ - if (squery->trying_as_is) - squery->status_as_is = status; - - /* - * If we ever get ARES_ENODATA along the way, record that; if the search - * should run to the very end and we got at least one ARES_ENODATA, - * then callers like ares_gethostbyname() may want to try a T_A search - * even if the last domain we queried for T_AAAA resource records - * returned ARES_ENOTFOUND. - */ - if (status == ARES_ENODATA) - squery->ever_got_nodata = 1; - - if (squery->next_domain < channel->ndomains) - { - /* Try the next domain. */ - status = cat_domain(squery->name, - channel->domains[squery->next_domain], &s); - if (status != ARES_SUCCESS) - end_squery(squery, status, NULL, 0); - else - { - squery->trying_as_is = 0; - squery->next_domain++; - ares_query(channel, s, squery->dnsclass, squery->type, - search_callback, squery); - free(s); - } - } - else if (squery->status_as_is == -1) - { - /* Try the name as-is at the end. */ - squery->trying_as_is = 1; - ares_query(channel, squery->name, squery->dnsclass, squery->type, - search_callback, squery); - } - else { - if (squery->status_as_is == ARES_ENOTFOUND && squery->ever_got_nodata) { - end_squery(squery, ARES_ENODATA, NULL, 0); - } - else - end_squery(squery, squery->status_as_is, NULL, 0); - } - } -} - -static void end_squery(struct search_query *squery, int status, - unsigned char *abuf, int alen) -{ - squery->callback(squery->arg, status, squery->timeouts, abuf, alen); - free(squery->name); - free(squery); -} - -/* Concatenate two domains. */ -static int cat_domain(const char *name, const char *domain, char **s) -{ - size_t nlen = strlen(name); - size_t dlen = strlen(domain); - - *s = malloc(nlen + 1 + dlen + 1); - if (!*s) - return ARES_ENOMEM; - memcpy(*s, name, nlen); - (*s)[nlen] = '.'; - memcpy(*s + nlen + 1, domain, dlen); - (*s)[nlen + 1 + dlen] = 0; - return ARES_SUCCESS; -} - -/* Determine if this name only yields one query. If it does, set *s to - * the string we should query, in an allocated buffer. If not, set *s - * to NULL. - */ -static int single_domain(ares_channel channel, const char *name, char **s) -{ - size_t len = strlen(name); - const char *hostaliases; - FILE *fp; - char *line = NULL; - int status; - size_t linesize; - const char *p, *q; - int error; - - /* If the name contains a trailing dot, then the single query is the name - * sans the trailing dot. - */ - if (name[len - 1] == '.') - { - *s = strdup(name); - return (*s) ? ARES_SUCCESS : ARES_ENOMEM; - } - - if (!(channel->flags & ARES_FLAG_NOALIASES) && !strchr(name, '.')) - { - /* The name might be a host alias. */ - hostaliases = getenv("HOSTALIASES"); - if (hostaliases) - { - fp = fopen(hostaliases, "r"); - if (fp) - { - while ((status = ares__read_line(fp, &line, &linesize)) - == ARES_SUCCESS) - { - if (strncasecmp(line, name, len) != 0 || - !ISSPACE(line[len])) - continue; - p = line + len; - while (ISSPACE(*p)) - p++; - if (*p) - { - q = p + 1; - while (*q && !ISSPACE(*q)) - q++; - *s = malloc(q - p + 1); - if (*s) - { - memcpy(*s, p, q - p); - (*s)[q - p] = 0; - } - free(line); - fclose(fp); - return (*s) ? ARES_SUCCESS : ARES_ENOMEM; - } - } - free(line); - fclose(fp); - if (status != ARES_SUCCESS) - return status; - } - else - { - error = errno; - switch(error) - { - case ENOENT: - case ESRCH: - break; - default: - DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n", - error, strerror(error))); - DEBUGF(fprintf(stderr, "Error opening file: %s\n", - hostaliases)); - *s = NULL; - return ARES_EFILE; - } - } - } - } - - if (channel->flags & ARES_FLAG_NOSEARCH || channel->ndomains == 0) - { - /* No domain search to do; just try the name as-is. */ - *s = strdup(name); - return (*s) ? ARES_SUCCESS : ARES_ENOMEM; - } - - *s = NULL; - return ARES_SUCCESS; -} |