autofs-5.1.4 - add fedfs-getsrvinfo.c

From: Ian Kent <raven@themaw.net>

Add the fedfs domain information discovery library functions.

Signed-off-by: Ian Kent <raven@themaw.net>

---

 CHANGELOG                |    1 

 fedfs/fedfs-getsrvinfo.c |  311 ++++++++++++++++++++++++++++++++++++++++++++++

 fedfs/fedfs-getsrvinfo.h |   52 ++++++++

 3 files changed, 364 insertions(+)

 create mode 100644 fedfs/fedfs-getsrvinfo.c

 create mode 100644 fedfs/fedfs-getsrvinfo.h

diff --git a/CHANGELOG b/CHANGELOG

index dbfb8389..8d6c737c 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -14,6 +14,7 @@ xx/xx/2018 autofs-5.1.5

 - Makefiles.rules: remove 'samples' from SUBDIRS.

 - dont allow trailing slash in master map mount points.

 - fix libresolv configure check.

+- add fedfs-getsrvinfo.c.

 19/12/2017 autofs-5.1.4

 - fix spec file url.

diff --git a/fedfs/fedfs-getsrvinfo.c b/fedfs/fedfs-getsrvinfo.c

new file mode 100644

index 00000000..02ad16b5

--- /dev/null

+++ b/fedfs/fedfs-getsrvinfo.c

@@ -0,0 +1,311 @@

+/*

+ * Copyright 2011 Oracle.  All rights reserved.

+ *

+ * This file is part of fedfs-utils.

+ *

+ * fedfs-utils is free software; you can redistribute it and/or modify

+ * it under the terms of the GNU General Public License version 2.0 as

+ * published by the Free Software Foundation.

+ *

+ * fedfs-utils 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 version 2.0 for more details.

+ *

+ * You should have received a copy of the GNU General Public License

+ * version 2.0 along with fedfs-utils.  If not, see:

+ *

+ *	http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt

+ */

+

+#ifdef HAVE_CONFIG_H

+#include <config.h>

+#endif

+

+#include <sys/types.h>

+#include <sys/socket.h>

+

+#include <stdbool.h>

+#include <string.h>

+#include <unistd.h>

+#include <stdlib.h>

+#include <stdint.h>

+

+#include <stdio.h>

+#include <errno.h>

+#include <netdb.h>

+#include <netinet/in.h>

+#include <arpa/inet.h>

+#include <arpa/nameser.h>

+#include <arpa/nameser_compat.h>

+#include <resolv.h>

+

+#include "fedfs-getsrvinfo.h"

+

+/**

+ * Parsing overlay for DNS query result record header.  Fields are

+ * in network byte order.

+ */

+struct rechdr {

+	uint16_t		 type;

+	uint16_t		 class;

+	uint32_t		 ttl;

+	uint16_t		 length;

+} __attribute__((__packed__));

+

+/**

+ * Parsing overlay for DNS query result SRV record data.  Fields

+ * are in network byte order.

+ */

+struct srv {

+	uint16_t		 priority;

+	uint16_t		 weight;

+	uint16_t		 port;

+	unsigned char		*target;

+} __attribute__((__packed__));

+

+/**

+ * Return C string matching error value of "status"

+ *

+ * @param status error status returned by getsrvinfo

+ * @return pointer to static NUL-terminated C string containing error message

+ */

+const char *

+gsi_strerror(int status)

+{

+	static char buf[256];

+

+	switch (status) {

+	case ESI_SUCCESS:

+		return "Success";

+	case ESI_NONAME:

+		return "Name not found";

+	case ESI_AGAIN:

+		return "Temporary failure in name resolution";

+	case ESI_FAIL:

+		return "Non-recoverable failure in name resolution";

+	case ESI_NODATA:

+		return "No SRV record returned";

+	case ESI_SERVICE:

+		return "Service is not available";

+	case ESI_MEMORY:

+		return "Memory allocation failure";

+	case ESI_SYSTEM:

+		snprintf(buf, sizeof(buf), "System error (%d): %s",

+				status, strerror(errno));

+		return buf;

+	case ESI_PARSE:

+		return "Failed to parse server response";

+	}

+

+	snprintf(buf, sizeof(buf), "Unknown error (%d)", status);

+	return buf;

+}

+

+/**

+ * Release a list of SRV records allocated by getsrvinfo()

+ *

+ * @param si pointer to first element of a list of struct srvinfo

+ *

+ */

+void freesrvinfo(struct srvinfo *si)

+{

+	struct srvinfo *tmp;

+

+	while (si != NULL) {

+		tmp = si;

+		si = si->si_next;

+		free(tmp->si_target);

+		free(tmp);

+	}

+}

+

+/**

+ * Ordering predicate for srvinfo lists

+ *

+ * @param a a srvinfo list element to compare

+ * @param b another srvinfo list element to compare

+ * @return true if "b" should fall later in the list than "a"

+ *

+ * See RFC 2782.   The list is ordered as follows:

+ *

+ *  o Lowest priority first.

+ *  o In each priority class, highest weight first.

+ */

+static _Bool

+srvinfo_is_after(const struct srvinfo *a, const struct srvinfo *b)

+{

+	if (a->si_priority > b->si_priority)

+		return true;

+	if (a->si_priority < b->si_priority)

+		return false;

+

+	if (a->si_weight < b->si_weight)

+		return true;

+	return false;

+}

+

+/**

+ * Insert a srvinfo element into a list

+ *

+ * @param head pointer to head of list of elements

+ * @param entry new list element to insert

+ *

+ */

+static void

+insert_srvinfo(struct srvinfo **head, struct srvinfo *entry)

+{

+	entry->si_next = *head;

+	*head = entry;

+}

+

+/**

+ * Insert a srvinfo element into a list, in order

+ *

+ * @param head pointer to head of list of elements

+ * @param entry new list element to insert

+ *

+ */

+static void

+insert_srvinfo_sorted(struct srvinfo **head, struct srvinfo *entry)

+{

+	struct srvinfo *spot, *back;

+

+	spot = *head;

+	back = NULL;

+	while (spot && srvinfo_is_after(spot, entry)) {

+		back = spot;

+		spot = spot->si_next;

+	}

+

+	if (spot == (*head))

+		insert_srvinfo(head, entry);

+	else {

+		insert_srvinfo(&spot, entry);

+		/* off the end of the list? */

+		if (spot == entry)

+			back->si_next = entry;

+	}

+}

+

+/**

+ * Retrieve list of SRV records from DNS service

+ *

+ * @param srvname NUL-terminated C string containing record type to look up

+ * @param domainname NUL-terminated C string containing domain name to look up

+ * @param si OUT: list of SRV record information retrieved

+ * @return zero on success, or an ESI_ status code describing the error

+ *

+ * Caller must free list of records using freesrvinfo().

+ */

+int

+getsrvinfo(const char *srvname, const char *domainname, struct srvinfo **si)

+{

+	unsigned char *msg, *eom, *comp_dn;

+	struct srvinfo *results;

+	unsigned short count, i;

+	int status, len;

+	char *exp_dn;

+	HEADER *hdr;

+

+	msg = calloc(1, NS_MAXMSG);

+	exp_dn = calloc(1, NS_MAXDNAME);

+	if (msg == NULL || exp_dn == NULL) {

+		status = ESI_MEMORY;

+		goto out;

+	}

+

+	_res.options |= RES_AAONLY;

+	len = res_querydomain(srvname, domainname, C_IN, T_SRV, msg, NS_MAXMSG);

+	if (len == -1) {

+		switch (h_errno) {

+		case HOST_NOT_FOUND:

+			status = ESI_NONAME;

+			break;

+		case TRY_AGAIN:

+			status = ESI_AGAIN;

+			break;

+		case NO_RECOVERY:

+			status = ESI_FAIL;

+			break;

+		case NO_DATA:

+			status = ESI_NODATA;

+			break;

+		default:

+			fprintf(stderr, "SRV query failed for %s.%s: %s\n",

+				srvname, domainname, hstrerror(h_errno));

+			status = ESI_FAIL;

+		}

+		goto out;

+	}

+

+	hdr = (HEADER *)msg;

+	count = ntohs(hdr->ancount);

+	if (count == 0) {

+		status = ESI_NODATA;

+		goto out;

+	}

+	eom = msg + len;

+

+	comp_dn = &msg[HFIXEDSZ];

+	comp_dn += dn_skipname(comp_dn, eom) + QFIXEDSZ;

+

+	results = NULL;

+	for (i = 0; i < count; i++) {

+		struct srvinfo *new;

+		struct srv *record;

+		int l;

+

+		l = dn_expand(msg, eom, comp_dn, exp_dn, NS_MAXDNAME);

+		if (l == -1) {

+			status = ESI_PARSE;

+			goto out_free;

+		}

+		comp_dn += l;

+

+		record = (struct srv *)&comp_dn[10];

+		comp_dn += 16;

+

+		l = dn_expand(msg, eom, comp_dn, exp_dn, NS_MAXDNAME);

+		if (l == -1) {

+			status = ESI_PARSE;

+			goto out_free;

+		}

+		comp_dn += l;

+

+		if (count == 1 && strcmp(exp_dn, ".") == 0) {

+			status = ESI_SERVICE;

+			goto out_free;

+		}

+

+		new = calloc(1, sizeof(*new));

+		if (new == NULL) {

+			status = ESI_MEMORY;

+			goto out;

+		}

+

+		new->si_target = strdup(exp_dn);

+		if (new->si_target == NULL) {

+			free(new);

+			status = ESI_MEMORY;

+			goto out;

+		}

+		new->si_priority = ntohs(record->priority);

+		new->si_weight = ntohs(record->weight);

+		new->si_port = ntohs(record->port);

+

+		insert_srvinfo_sorted(&results, new);

+	}

+

+	status = ESI_SUCCESS;

+	*si = results;

+

+out:

+	free(exp_dn);

+	free(msg);

+	return status;

+

+out_free:

+	freesrvinfo(results);

+	goto out;

+}

diff --git a/fedfs/fedfs-getsrvinfo.h b/fedfs/fedfs-getsrvinfo.h

new file mode 100644

index 00000000..13170359

--- /dev/null

+++ b/fedfs/fedfs-getsrvinfo.h

@@ -0,0 +1,52 @@

+/*

+ * Copyright 2011 Oracle.  All rights reserved.

+ *

+ * This file is part of fedfs-utils.

+ *

+ * fedfs-utils is free software; you can redistribute it and/or modify

+ * it under the terms of the GNU General Public License version 2.0 as

+ * published by the Free Software Foundation.

+ *

+ * fedfs-utils 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 version 2.0 for more details.

+ *

+ * You should have received a copy of the GNU General Public License

+ * version 2.0 along with fedfs-utils.  If not, see:

+ *

+ *	http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt

+ */

+

+#ifndef _FEDFS_GETSRVINFO_H_

+#define _FEDFS_GETSRVINFO_H_

+

+/**

+ * Single list element containing SRV record data

+ */

+struct srvinfo {

+	struct srvinfo		*si_next;

+	char			*si_target;

+	unsigned short		 si_priority;

+	unsigned short		 si_weight;

+	unsigned short		 si_port;

+};

+

+enum {

+	ESI_SUCCESS	= 0,

+	ESI_NONAME	= -2,

+	ESI_AGAIN	= -3,

+	ESI_FAIL	= -4,

+	ESI_NODATA	= -5,

+	ESI_SERVICE	= -8,

+	ESI_MEMORY	= -10,

+	ESI_SYSTEM	= -11,

+	ESI_PARSE	= -1000,

+};

+

+int		 getsrvinfo(const char *srvname, const char *domainname,

+				struct srvinfo **si);

+void		 freesrvinfo(struct srvinfo *si);

+const char	*gsi_strerror(int status);

+

+#endif	/* !_FEDFS_GETSRVINFO_H_ */