bin/58133: back port libmap.conf feature for 4-stable
Norikatsu Shigemura
nork at FreeBSD.org
Thu Oct 16 09:10:25 PDT 2003
>Number: 58133
>Category: bin
>Synopsis: back port libmap.conf feature for 4-stable
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Thu Oct 16 09:10:16 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator: Norikatsu Shigemura
>Release: FreeBSD 4.9-RC i386
>Organization:
Ensure Technology Ltd. (http://www.ensure-tech.co.jp)
>Environment:
System: FreeBSD sakura.ninth-nine.com 4.9-RC FreeBSD 4.9-RC #3: Fri Oct 3 15:57:33 JST 2003 nork at sakura.ninth-nine.com:/usr/obj/usr/src/sys/SAKURA i386
>Description:
I back-port-ed /etc/libmap.conf feature on 5-current written
by mdodd@ to 4-stable. I requested mdodd@ to back port this
feature. But mdodd@ said following lines and didn't have
mdodd@'s heart in it.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Subject: Re: /etc/libmap.conf MFC?
Date: Fri, 20 Jun 2003 18:10:57 -0400 (EDT)
on freebsd-stable@, mdodd said,
You should upgrade to 5.1 if it has features that you want.
Adding new features to the STABLE branch this late in its lifetime
seems pointless.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>How-To-Repeat:
N/A
>Fix:
--- libmap_4stable.diff begins here ---
diff -urN libexec/rtld-elf.old/Makefile libexec/rtld-elf/Makefile
--- libexec/rtld-elf.old/Makefile Sun Jun 23 06:32:35 2002
+++ libexec/rtld-elf/Makefile Wed Oct 8 02:50:10 2003
@@ -2,7 +2,7 @@
PROG= ld-elf.so.1
SRCS= rtld_start.S rtld.c lockdflt.c map_object.c malloc.c \
- xmalloc.c debug.c reloc.c
+ xmalloc.c debug.c reloc.c libmap.c
MAN= rtld.1
CFLAGS+= -Wall -DFREEBSD_ELF -I${.CURDIR}/${MACHINE_ARCH} -I${.CURDIR}
LDFLAGS+= -nostdlib -e .rtld_start
diff -urN libexec/rtld-elf.old/libmap.c libexec/rtld-elf/libmap.c
--- libexec/rtld-elf.old/libmap.c Thu Jan 1 09:00:00 1970
+++ libexec/rtld-elf/libmap.c Wed Oct 8 02:44:17 2003
@@ -0,0 +1,255 @@
+/*
+ * $FreeBSD: src/libexec/rtld-elf/libmap.c,v 1.9 2003/09/13 21:43:08 mdodd Exp $
+ */
+
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/queue.h>
+#include <sys/param.h>
+
+#include "debug.h"
+#include "rtld.h"
+#include "libmap.h"
+
+#ifndef _PATH_LIBMAP_CONF
+#define _PATH_LIBMAP_CONF "/etc/libmap.conf"
+#endif
+
+TAILQ_HEAD(lm_list, lm);
+struct lm {
+ char *f;
+ char *t;
+
+ TAILQ_ENTRY(lm) lm_link;
+};
+
+TAILQ_HEAD(lmp_list, lmp) lmp_head = TAILQ_HEAD_INITIALIZER(lmp_head);
+struct lmp {
+ char *p;
+ struct lm_list lml;
+ TAILQ_ENTRY(lmp) lmp_link;
+};
+
+static void lm_add (const char *, const char *, const char *);
+static void lm_free (struct lm_list *);
+static char * lml_find (struct lm_list *, const char *);
+static struct lm_list * lmp_find (const char *);
+static struct lm_list * lmp_init (char *);
+
+#define iseol(c) (((c) == '#') || ((c) == '\0') || \
+ ((c) == '\n') || ((c) == '\r'))
+
+int
+lm_init (void)
+{
+ FILE *fp;
+ char *cp;
+ char *f, *t, *p, *c;
+ char prog[MAXPATHLEN];
+ char line[MAXPATHLEN + 2];
+
+ dbg("%s()", __func__);
+
+ TAILQ_INIT(&lmp_head);
+
+ if ((fp = fopen(_PATH_LIBMAP_CONF, "r")) == NULL)
+ return (1);
+
+ p = NULL;
+ while ((cp = fgets(line, MAXPATHLEN + 1, fp)) != NULL) {
+ t = f = c = NULL;
+
+ /* Skip over leading space */
+ while (isspace(*cp)) cp++;
+
+ /* Found a comment or EOL */
+ if (iseol(*cp)) continue;
+
+ /* Found a constraint selector */
+ if (*cp == '[') {
+ cp++;
+
+ /* Skip leading space */
+ while (isspace(*cp)) cp++;
+
+ /* Found comment, EOL or end of selector */
+ if (iseol(*cp) || *cp == ']')
+ continue;
+
+ c = cp++;
+ /* Skip to end of word */
+ while (!isspace(*cp) && !iseol(*cp) && *cp != ']')
+ cp++;
+
+ /* Skip and zero out trailing space */
+ while (isspace(*cp)) *cp++ = '\0';
+
+ /* Check if there is a closing brace */
+ if (*cp != ']') continue;
+
+ /* Terminate string if there was no trailing space */
+ *cp++ = '\0';
+
+ /*
+ * There should be nothing except whitespace or comment
+ from this point to the end of the line.
+ */
+ while(isspace(*cp)) *cp++;
+ if (!iseol(*cp)) continue;
+
+ strcpy(prog, c);
+ p = prog;
+ continue;
+ }
+
+ /* Parse the 'from' candidate. */
+ f = cp++;
+ while (!isspace(*cp) && !iseol(*cp)) cp++;
+
+ /* Skip and zero out the trailing whitespace */
+ while (isspace(*cp)) *cp++ = '\0';
+
+ /* Found a comment or EOL */
+ if (iseol(*cp)) continue;
+
+ /* Parse 'to' mapping */
+ t = cp++;
+ while (!isspace(*cp) && !iseol(*cp)) cp++;
+
+ /* Skip and zero out the trailing whitespace */
+ while (isspace(*cp)) *cp++ = '\0';
+
+ /* Should be no extra tokens at this point */
+ if (!iseol(*cp)) continue;
+
+ *cp = '\0';
+ lm_add(p, f, t);
+ }
+ fclose(fp);
+ return (0);
+}
+
+static void
+lm_free (struct lm_list *lml)
+{
+ struct lm *lm;
+
+ dbg("%s(%p)", __func__, lml);
+
+ while (!TAILQ_EMPTY(lml)) {
+ lm = TAILQ_FIRST(lml);
+ TAILQ_REMOVE(lml, lm, lm_link);
+ free(lm->f);
+ free(lm->t);
+ free(lm);
+ }
+ return;
+}
+
+void
+lm_fini (void)
+{
+ struct lmp *lmp;
+
+ dbg("%s()", __func__);
+
+ while (!TAILQ_EMPTY(&lmp_head)) {
+ lmp = TAILQ_FIRST(&lmp_head);
+ TAILQ_REMOVE(&lmp_head, lmp, lmp_link);
+ free(lmp->p);
+ lm_free(&lmp->lml);
+ free(lmp);
+ }
+ return;
+}
+
+static void
+lm_add (const char *p, const char *f, const char *t)
+{
+ struct lm_list *lml;
+ struct lm *lm;
+
+ if (p == NULL)
+ p = "$DEFAULT$";
+
+ dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t);
+
+ if ((lml = lmp_find(p)) == NULL)
+ lml = lmp_init(xstrdup(p));
+
+ lm = xmalloc(sizeof(struct lm));
+ lm->f = xstrdup(f);
+ lm->t = xstrdup(t);
+ TAILQ_INSERT_HEAD(lml, lm, lm_link);
+}
+
+char *
+lm_find (const char *p, const char *f)
+{
+ struct lm_list *lml;
+ char *t;
+
+ dbg("%s(\"%s\", \"%s\")", __func__, p, f);
+
+ if (p != NULL && (lml = lmp_find(p)) != NULL) {
+ t = lml_find(lml, f);
+ if (t != NULL) {
+ /*
+ * Add a global mapping if we have
+ * a successful constrained match.
+ */
+ lm_add(NULL, f, t);
+ return (t);
+ }
+ }
+ lml = lmp_find("$DEFAULT$");
+ if (lml != NULL)
+ return (lml_find(lml, f));
+ else
+ return (NULL);
+}
+
+static char *
+lml_find (struct lm_list *lmh, const char *f)
+{
+ struct lm *lm;
+
+ dbg("%s(%p, \"%s\")", __func__, lmh, f);
+
+ TAILQ_FOREACH(lm, lmh, lm_link)
+ if ((strncmp(f, lm->f, strlen(lm->f)) == 0) &&
+ (strlen(f) == strlen(lm->f)))
+ return (lm->t);
+ return NULL;
+}
+
+static struct lm_list *
+lmp_find (const char *n)
+{
+ struct lmp *lmp;
+
+ dbg("%s(\"%s\")", __func__, n);
+
+ TAILQ_FOREACH(lmp, &lmp_head, lmp_link)
+ if ((strncmp(n, lmp->p, strlen(lmp->p)) == 0) &&
+ (strlen(n) == strlen(lmp->p)))
+ return (&lmp->lml);
+ return (NULL);
+}
+
+static struct lm_list *
+lmp_init (char *n)
+{
+ struct lmp *lmp;
+
+ dbg("%s(\"%s\")", __func__, n);
+
+ lmp = xmalloc(sizeof(struct lmp));
+ lmp->p = n;
+ TAILQ_INIT(&lmp->lml);
+ TAILQ_INSERT_HEAD(&lmp_head, lmp, lmp_link);
+
+ return (&lmp->lml);
+}
diff -urN libexec/rtld-elf.old/libmap.h libexec/rtld-elf/libmap.h
--- libexec/rtld-elf.old/libmap.h Thu Jan 1 09:00:00 1970
+++ libexec/rtld-elf/libmap.h Wed Oct 8 02:44:17 2003
@@ -0,0 +1,7 @@
+/*
+ * $FreeBSD: src/libexec/rtld-elf/libmap.h,v 1.2 2003/09/13 21:43:08 mdodd Exp $
+ */
+
+int lm_init (void);
+void lm_fini (void);
+char * lm_find (const char *, const char *);
diff -urN libexec/rtld-elf.old/rtld.1 libexec/rtld-elf/rtld.1
--- libexec/rtld-elf.old/rtld.1 Sat Jan 12 02:35:52 2002
+++ libexec/rtld-elf/rtld.1 Wed Oct 8 02:50:10 2003
@@ -88,6 +88,9 @@
other shared libraries.
If the directory is not specified then
the directories specified by
+.It Ev LD_LIBMAP_DISABLE
+If set, disables the use of
+.Xr libmap.conf 5 .
.Ev LD_LIBRARY_PATH
will be searched first
followed by the set of built-in standard directories.
@@ -147,9 +150,12 @@
.Sh FILES
.Bl -tag -width indent
.It Pa /var/run/ld-elf.so.hints
+.It Pa /etc/libmap.conf
+The libmap configuration file.
.El
.Sh SEE ALSO
.Xr ld 1 ,
.Xr ldd 1 ,
.Xr elf 5 ,
+.Xr libmap.conf 5 ,
.Xr ldconfig 8
diff -urN libexec/rtld-elf.old/rtld.c libexec/rtld-elf/rtld.c
--- libexec/rtld-elf.old/rtld.c Sat Feb 22 00:50:43 2003
+++ libexec/rtld-elf/rtld.c Wed Oct 8 02:50:10 2003
@@ -52,6 +52,7 @@
#include "debug.h"
#include "rtld.h"
+#include "libmap.h"
#define END_SYM "_end"
#define PATH_RTLD "/usr/libexec/ld-elf.so.1"
@@ -131,6 +132,7 @@
*/
static char *error_message; /* Message for dlerror(), or NULL */
struct r_debug r_debug; /* for GDB; */
+static bool libmap_disable; /* Disable libmap */
static bool trust; /* False for setuid and setgid programs */
static char *ld_bind_now; /* Environment variable for immediate binding */
static char *ld_debug; /* Environment variable for debugging */
@@ -293,6 +295,7 @@
ld_bind_now = getenv("LD_BIND_NOW");
if (trust) {
ld_debug = getenv("LD_DEBUG");
+ libmap_disable = getenv("LD_LIBMAP_DISABLE") != NULL;
ld_library_path = getenv("LD_LIBRARY_PATH");
ld_preload = getenv("LD_PRELOAD");
}
@@ -366,6 +369,9 @@
sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
sym_zero.st_shndx = SHN_ABS;
+ if (!libmap_disable)
+ libmap_disable = (bool)lm_init();
+
dbg("loading LD_PRELOAD libraries");
if (load_preload_objects() == -1)
die();
@@ -791,19 +797,24 @@
* /usr/lib
*/
static char *
-find_library(const char *name, const Obj_Entry *refobj)
+find_library(const char *xname, const Obj_Entry *refobj)
{
char *pathname;
+ char *name;
- if (strchr(name, '/') != NULL) { /* Hard coded pathname */
- if (name[0] != '/' && !trust) {
+ if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
+ if (xname[0] != '/' && !trust) {
_rtld_error("Absolute pathname required for shared object \"%s\"",
- name);
+ xname);
return NULL;
}
- return xstrdup(name);
+ return xstrdup(xname);
}
+ if (libmap_disable || (refobj == NULL) ||
+ (name = lm_find(refobj->path, xname)) == NULL)
+ name = (char *)xname;
+
dbg(" Searching for \"%s\"", name);
if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
@@ -1433,6 +1444,8 @@
obj->refcount = 0;
objlist_call_fini(&list_fini);
/* No need to remove the items from the list, since we are exiting. */
+ if (!libmap_disable)
+ lm_fini();
}
static void *
--- libmap_4stable.diff ends here ---
>Release-Note:
>Audit-Trail:
>Unformatted:
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