freebsd-dev/lib/libgeom/geom_xml2tree.c
Alexander Motin 7f16b501e2 GEOM: Introduce partial confxml API
Traditionally the GEOM's primary channel of information from kernel to
user-space was confxml, fetched by libgeom through kern.geom.confxml
sysctl.  It is convenient and informative, representing full state of
GEOM in a single XML document.  But problems start to arise on systems
with hundreds of disks, where the full confxml size reaches many
megabytes, taking significant time to first write it and then parse.

This patch introduces alternative solution, allowing to fetch much
smaller XML document, subset of the full confxml, limited to 64KB and
representing only one specified geom and optionally its parents.  It
uses existing GEOM control interface, extended with new "getxml" verb.
In case of any error, such as the buffer overflow, it just transparently
falls back to traditional full confxml.  This patch uses the new API in
user-space GEOM tools where it is possible.

Reviewed by:	imp
MFC after:	2 month
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D34529
2022-03-12 11:55:52 -05:00

556 lines
13 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause-FreeBSD
*
* Copyright (c) 2003 Poul-Henning Kamp
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <stdio.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <ctype.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/queue.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <err.h>
#include <bsdxml.h>
#include <libgeom.h>
struct mystate {
struct gmesh *mesh;
struct gclass *class;
struct ggeom *geom;
struct gprovider *provider;
struct gconsumer *consumer;
int level;
struct sbuf *sbuf[20];
struct gconf *config;
int nident;
XML_Parser parser;
int error;
};
static void
StartElement(void *userData, const char *name, const char **attr)
{
struct mystate *mt;
void *id;
void *ref;
int i;
mt = userData;
mt->level++;
mt->sbuf[mt->level] = sbuf_new_auto();
id = NULL;
ref = NULL;
for (i = 0; attr[i] != NULL; i += 2) {
if (!strcmp(attr[i], "id")) {
id = (void *)strtoul(attr[i + 1], NULL, 0);
mt->nident++;
} else if (!strcmp(attr[i], "ref")) {
ref = (void *)strtoul(attr[i + 1], NULL, 0);
} else
printf("%*.*s[%s = %s]\n",
mt->level + 1, mt->level + 1, "",
attr[i], attr[i + 1]);
}
if (!strcmp(name, "class") && mt->class == NULL) {
mt->class = calloc(1, sizeof *mt->class);
if (mt->class == NULL) {
mt->error = errno;
XML_StopParser(mt->parser, 0);
warn("Cannot allocate memory during processing of '%s' "
"element", name);
return;
}
mt->class->lg_id = id;
LIST_INSERT_HEAD(&mt->mesh->lg_class, mt->class, lg_class);
LIST_INIT(&mt->class->lg_geom);
LIST_INIT(&mt->class->lg_config);
return;
}
if (!strcmp(name, "geom") && mt->geom == NULL) {
mt->geom = calloc(1, sizeof *mt->geom);
if (mt->geom == NULL) {
mt->error = errno;
XML_StopParser(mt->parser, 0);
warn("Cannot allocate memory during processing of '%s' "
"element", name);
return;
}
mt->geom->lg_id = id;
LIST_INSERT_HEAD(&mt->class->lg_geom, mt->geom, lg_geom);
LIST_INIT(&mt->geom->lg_provider);
LIST_INIT(&mt->geom->lg_consumer);
LIST_INIT(&mt->geom->lg_config);
return;
}
if (!strcmp(name, "class") && mt->geom != NULL) {
mt->geom->lg_class = ref;
return;
}
if (!strcmp(name, "consumer") && mt->consumer == NULL) {
mt->consumer = calloc(1, sizeof *mt->consumer);
if (mt->consumer == NULL) {
mt->error = errno;
XML_StopParser(mt->parser, 0);
warn("Cannot allocate memory during processing of '%s' "
"element", name);
return;
}
mt->consumer->lg_id = id;
LIST_INSERT_HEAD(&mt->geom->lg_consumer, mt->consumer,
lg_consumer);
LIST_INIT(&mt->consumer->lg_config);
return;
}
if (!strcmp(name, "geom") && mt->consumer != NULL) {
mt->consumer->lg_geom = ref;
return;
}
if (!strcmp(name, "provider") && mt->consumer != NULL) {
mt->consumer->lg_provider = ref;
return;
}
if (!strcmp(name, "provider") && mt->provider == NULL) {
mt->provider = calloc(1, sizeof *mt->provider);
if (mt->provider == NULL) {
mt->error = errno;
XML_StopParser(mt->parser, 0);
warn("Cannot allocate memory during processing of '%s' "
"element", name);
return;
}
mt->provider->lg_id = id;
LIST_INSERT_HEAD(&mt->geom->lg_provider, mt->provider,
lg_provider);
LIST_INIT(&mt->provider->lg_consumers);
LIST_INIT(&mt->provider->lg_config);
return;
}
if (!strcmp(name, "geom") && mt->provider != NULL) {
mt->provider->lg_geom = ref;
return;
}
if (!strcmp(name, "config")) {
if (mt->provider != NULL) {
mt->config = &mt->provider->lg_config;
return;
}
if (mt->consumer != NULL) {
mt->config = &mt->consumer->lg_config;
return;
}
if (mt->geom != NULL) {
mt->config = &mt->geom->lg_config;
return;
}
if (mt->class != NULL) {
mt->config = &mt->class->lg_config;
return;
}
}
}
static void
EndElement(void *userData, const char *name)
{
struct mystate *mt;
struct gconf *c;
struct gconfig *gc;
char *p;
mt = userData;
p = NULL;
if (sbuf_finish(mt->sbuf[mt->level]) == 0)
p = strdup(sbuf_data(mt->sbuf[mt->level]));
sbuf_delete(mt->sbuf[mt->level]);
mt->sbuf[mt->level] = NULL;
mt->level--;
if (p == NULL) {
mt->error = errno;
XML_StopParser(mt->parser, 0);
warn("Cannot allocate memory during processing of '%s' "
"element", name);
return;
}
if (strlen(p) == 0) {
free(p);
p = NULL;
}
if (!strcmp(name, "name")) {
if (mt->provider != NULL) {
mt->provider->lg_name = p;
return;
} else if (mt->geom != NULL) {
mt->geom->lg_name = p;
return;
} else if (mt->class != NULL) {
mt->class->lg_name = p;
return;
}
}
if (!strcmp(name, "rank") && mt->geom != NULL) {
mt->geom->lg_rank = strtoul(p, NULL, 0);
free(p);
return;
}
if (!strcmp(name, "mode") && mt->provider != NULL) {
mt->provider->lg_mode = p;
return;
}
if (!strcmp(name, "mode") && mt->consumer != NULL) {
mt->consumer->lg_mode = p;
return;
}
if (!strcmp(name, "mediasize") && mt->provider != NULL) {
mt->provider->lg_mediasize = strtoumax(p, NULL, 0);
free(p);
return;
}
if (!strcmp(name, "sectorsize") && mt->provider != NULL) {
mt->provider->lg_sectorsize = strtoul(p, NULL, 0);
free(p);
return;
}
if (!strcmp(name, "stripesize") && mt->provider != NULL) {
mt->provider->lg_stripesize = strtoumax(p, NULL, 0);
free(p);
return;
}
if (!strcmp(name, "stripeoffset") && mt->provider != NULL) {
mt->provider->lg_stripeoffset = strtoumax(p, NULL, 0);
free(p);
return;
}
if (!strcmp(name, "config")) {
mt->config = NULL;
free(p);
return;
}
if (mt->config != NULL || (!strcmp(name, "wither") &&
(mt->provider != NULL || mt->geom != NULL))) {
if (mt->config != NULL)
c = mt->config;
else if (mt->provider != NULL)
c = &mt->provider->lg_config;
else
c = &mt->geom->lg_config;
gc = calloc(1, sizeof *gc);
if (gc == NULL) {
mt->error = errno;
XML_StopParser(mt->parser, 0);
warn("Cannot allocate memory during processing of '%s' "
"element", name);
free(p);
return;
}
gc->lg_name = strdup(name);
if (gc->lg_name == NULL) {
mt->error = errno;
XML_StopParser(mt->parser, 0);
warn("Cannot allocate memory during processing of '%s' "
"element", name);
free(gc);
free(p);
return;
}
gc->lg_val = p;
LIST_INSERT_HEAD(c, gc, lg_config);
return;
}
if (p != NULL) {
#if DEBUG_LIBGEOM > 0
printf("Unexpected XML: name=%s data=\"%s\"\n", name, p);
#endif
free(p);
}
if (!strcmp(name, "consumer") && mt->consumer != NULL) {
mt->consumer = NULL;
return;
}
if (!strcmp(name, "provider") && mt->provider != NULL) {
mt->provider = NULL;
return;
}
if (!strcmp(name, "geom") && mt->consumer != NULL) {
return;
}
if (!strcmp(name, "geom") && mt->provider != NULL) {
return;
}
if (!strcmp(name, "geom") && mt->geom != NULL) {
mt->geom = NULL;
return;
}
if (!strcmp(name, "class") && mt->geom != NULL) {
return;
}
if (!strcmp(name, "class") && mt->class != NULL) {
mt->class = NULL;
return;
}
}
static void
CharData(void *userData , const XML_Char *s , int len)
{
struct mystate *mt;
const char *b, *e;
mt = userData;
b = s;
e = s + len - 1;
while (isspace(*b) && b < e)
b++;
while (isspace(*e) && e > b)
e--;
if (e != b || (*b && !isspace(*b)))
sbuf_bcat(mt->sbuf[mt->level], b, e - b + 1);
}
struct gident *
geom_lookupid(struct gmesh *gmp, const void *id)
{
struct gident *gip;
for (gip = gmp->lg_ident; gip->lg_id != NULL; gip++)
if (gip->lg_id == id)
return (gip);
return (NULL);
}
static void *
geom_lookupidptr(struct gmesh *gmp, const void *id)
{
struct gident *gip;
gip = geom_lookupid(gmp, id);
if (gip)
return (gip->lg_ptr);
return (NULL);
}
int
geom_xml2tree(struct gmesh *gmp, char *p)
{
XML_Parser parser;
struct mystate *mt;
struct gclass *cl;
struct ggeom *ge;
struct gprovider *pr;
struct gconsumer *co;
int error, i;
memset(gmp, 0, sizeof *gmp);
LIST_INIT(&gmp->lg_class);
parser = XML_ParserCreate(NULL);
if (parser == NULL)
return (ENOMEM);
mt = calloc(1, sizeof *mt);
if (mt == NULL) {
XML_ParserFree(parser);
return (ENOMEM);
}
mt->mesh = gmp;
mt->parser = parser;
error = 0;
XML_SetUserData(parser, mt);
XML_SetElementHandler(parser, StartElement, EndElement);
XML_SetCharacterDataHandler(parser, CharData);
i = XML_Parse(parser, p, strlen(p), 1);
if (mt->error != 0)
error = mt->error;
else if (i != 1) {
error = XML_GetErrorCode(parser) == XML_ERROR_NO_MEMORY ?
ENOMEM : EILSEQ;
}
XML_ParserFree(parser);
if (error != 0) {
free(mt);
return (error);
}
gmp->lg_ident = calloc(sizeof *gmp->lg_ident, mt->nident + 1);
free(mt);
if (gmp->lg_ident == NULL)
return (ENOMEM);
i = 0;
/* Collect all identifiers */
LIST_FOREACH(cl, &gmp->lg_class, lg_class) {
gmp->lg_ident[i].lg_id = cl->lg_id;
gmp->lg_ident[i].lg_ptr = cl;
gmp->lg_ident[i].lg_what = ISCLASS;
i++;
LIST_FOREACH(ge, &cl->lg_geom, lg_geom) {
gmp->lg_ident[i].lg_id = ge->lg_id;
gmp->lg_ident[i].lg_ptr = ge;
gmp->lg_ident[i].lg_what = ISGEOM;
i++;
LIST_FOREACH(pr, &ge->lg_provider, lg_provider) {
gmp->lg_ident[i].lg_id = pr->lg_id;
gmp->lg_ident[i].lg_ptr = pr;
gmp->lg_ident[i].lg_what = ISPROVIDER;
i++;
}
LIST_FOREACH(co, &ge->lg_consumer, lg_consumer) {
gmp->lg_ident[i].lg_id = co->lg_id;
gmp->lg_ident[i].lg_ptr = co;
gmp->lg_ident[i].lg_what = ISCONSUMER;
i++;
}
}
}
/* Substitute all identifiers */
LIST_FOREACH(cl, &gmp->lg_class, lg_class) {
LIST_FOREACH(ge, &cl->lg_geom, lg_geom) {
ge->lg_class = geom_lookupidptr(gmp, ge->lg_class);
LIST_FOREACH(pr, &ge->lg_provider, lg_provider)
pr->lg_geom = geom_lookupidptr(gmp, pr->lg_geom);
LIST_FOREACH(co, &ge->lg_consumer, lg_consumer) {
co->lg_geom = geom_lookupidptr(gmp, co->lg_geom);
if (co->lg_provider != NULL) {
co->lg_provider = geom_lookupidptr(gmp,
co->lg_provider);
if (co->lg_provider != NULL) {
LIST_INSERT_HEAD(
&co->lg_provider->lg_consumers,
co, lg_consumers);
}
}
}
}
}
return (0);
}
int
geom_gettree(struct gmesh *gmp)
{
char *p;
int error;
p = geom_getxml();
if (p == NULL)
return (errno);
error = geom_xml2tree(gmp, p);
free(p);
return (error);
}
int
geom_gettree_geom(struct gmesh *gmp, const char *c, const char *g, int parents)
{
char *p;
int error;
p = geom_getxml_geom(c, g, parents);
if (p == NULL)
return (errno);
error = geom_xml2tree(gmp, p);
free(p);
return (error);
}
static void
delete_config(struct gconf *gp)
{
struct gconfig *cf;
for (;;) {
cf = LIST_FIRST(gp);
if (cf == NULL)
return;
LIST_REMOVE(cf, lg_config);
free(cf->lg_name);
free(cf->lg_val);
free(cf);
}
}
void
geom_deletetree(struct gmesh *gmp)
{
struct gclass *cl;
struct ggeom *ge;
struct gprovider *pr;
struct gconsumer *co;
free(gmp->lg_ident);
gmp->lg_ident = NULL;
for (;;) {
cl = LIST_FIRST(&gmp->lg_class);
if (cl == NULL)
break;
LIST_REMOVE(cl, lg_class);
delete_config(&cl->lg_config);
if (cl->lg_name) free(cl->lg_name);
for (;;) {
ge = LIST_FIRST(&cl->lg_geom);
if (ge == NULL)
break;
LIST_REMOVE(ge, lg_geom);
delete_config(&ge->lg_config);
if (ge->lg_name) free(ge->lg_name);
for (;;) {
pr = LIST_FIRST(&ge->lg_provider);
if (pr == NULL)
break;
LIST_REMOVE(pr, lg_provider);
delete_config(&pr->lg_config);
if (pr->lg_name) free(pr->lg_name);
if (pr->lg_mode) free(pr->lg_mode);
free(pr);
}
for (;;) {
co = LIST_FIRST(&ge->lg_consumer);
if (co == NULL)
break;
LIST_REMOVE(co, lg_consumer);
delete_config(&co->lg_config);
if (co->lg_mode) free(co->lg_mode);
free(co);
}
free(ge);
}
free(cl);
}
}