freebsd-dev/libexec/rtld-elf/libmap.c
Matthew N. Dodd 5b08cb0449 Description from Dan:
Another handy libmap patch.  Lets you do stuff like this:

	LD_LIBMAP="libpthread.so.1=libthr.so.1" mythreadedapp

	If you already have a program-specific override in libmap.conf, note
	that you must use a program-specific override in LD_LIBMAP:

	LD_LIBMAP="[mythreadedapp],libpthread.so.1=libthr.so.1" mythreadedapp

PR:		bin/74471
Submitted by:	Dan Nelson <dnelson AT allantgroup.com>
MFC after:	2 weeks
2005-02-04 02:46:41 +00:00

372 lines
6.9 KiB
C

/*
* $FreeBSD$
*/
#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
#ifdef COMPAT_32BIT
#undef _PATH_LIBMAP_CONF
#define _PATH_LIBMAP_CONF "/etc/libmap32.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;
enum { T_EXACT=0, T_BASENAME, T_DIRECTORY } type;
struct lm_list lml;
TAILQ_ENTRY(lmp) lmp_link;
};
static int lm_count;
static void lmc_parse (FILE *);
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 *);
static const char * quickbasename (const char *);
static int readstrfn (void * cookie, char *buf, int len);
static int closestrfn (void * cookie);
#define iseol(c) (((c) == '#') || ((c) == '\0') || \
((c) == '\n') || ((c) == '\r'))
int
lm_init (char *libmap_override)
{
FILE *fp;
dbg("%s(\"%s\")", __func__, libmap_override);
TAILQ_INIT(&lmp_head);
fp = fopen(_PATH_LIBMAP_CONF, "r");
if (fp) {
lmc_parse(fp);
fclose(fp);
}
if (libmap_override) {
char *p;
/* do some character replacement to make $LIBMAP look like a
text file, then "open" it with funopen */
libmap_override = xstrdup(libmap_override);
for (p = libmap_override; *p; p++) {
switch (*p) {
case '=':
*p = ' '; break;
case ',':
*p = '\n'; break;
}
}
fp = funopen(libmap_override, readstrfn, NULL, NULL, closestrfn);
if (fp) {
lmc_parse(fp);
fclose(fp);
}
}
return (lm_count == 0);
}
static void
lmc_parse (FILE *fp)
{
char *cp;
char *f, *t, *c, *p;
char prog[MAXPATHLEN];
char line[MAXPATHLEN + 2];
dbg("%s(%p)", __func__, fp);
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);
}
}
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$";
dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t);
if ((lml = lmp_find(p)) == NULL)
lml = lmp_init(xstrdup(p));
lm = xmalloc(sizeof(struct lm));
lm->f = xstrdup(f);
lm->t = xstrdup(t);
TAILQ_INSERT_HEAD(lml, lm, lm_link);
lm_count++;
}
char *
lm_find (const char *p, const char *f)
{
struct lm_list *lml;
char *t;
dbg("%s(\"%s\", \"%s\")", __func__, p, f);
if (p != NULL && (lml = lmp_find(p)) != NULL) {
t = lml_find(lml, f);
if (t != NULL) {
/*
* Add a global mapping if we have
* a successful constrained match.
*/
lm_add(NULL, f, t);
return (t);
}
}
lml = lmp_find("$DEFAULT$");
if (lml != NULL)
return (lml_find(lml, f));
else
return (NULL);
}
/* Given a libmap translation list and a library name, return the
replacement library, or NULL */
#ifdef COMPAT_32BIT
char *
lm_findn (const char *p, const char *f, const int n)
{
char pathbuf[64], *s, *t;
if (n < sizeof(pathbuf) - 1) {
memcpy(pathbuf, f, n);
pathbuf[n] = '\0';
s = pathbuf;
} else {
s = xmalloc(n + 1);
strcpy(s, f);
}
t = lm_find(p, s);
if (s != pathbuf)
free(s);
return (t);
}
#endif
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 (strcmp(f, lm->f) == 0)
return (lm->t);
return (NULL);
}
/* Given an executable name, return a pointer to the translation list or
NULL if no matches */
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 ((lmp->type == T_EXACT && strcmp(n, lmp->p) == 0) ||
(lmp->type == T_DIRECTORY && strncmp(n, lmp->p, strlen(lmp->p)) == 0) ||
(lmp->type == T_BASENAME && strcmp(quickbasename(n), lmp->p) == 0))
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;
if (n[strlen(n)-1] == '/')
lmp->type = T_DIRECTORY;
else if (strchr(n,'/') == NULL)
lmp->type = T_BASENAME;
else
lmp->type = T_EXACT;
TAILQ_INIT(&lmp->lml);
TAILQ_INSERT_HEAD(&lmp_head, lmp, lmp_link);
return (&lmp->lml);
}
/* libc basename is overkill. Return a pointer to the character after the
last /, or the original string if there are no slashes. */
static const char *
quickbasename (const char *path)
{
const char *p = path;
for (; *path; path++) {
if (*path == '/')
p = path+1;
}
return (p);
}
static int
readstrfn(void * cookie, char *buf, int len)
{
static char *current;
static int left;
int copied;
copied = 0;
if (!current) {
current = cookie;
left = strlen(cookie);
}
while (*current && left && len) {
*buf++ = *current++;
left--;
len--;
copied++;
}
return copied;
}
static int
closestrfn(void * cookie)
{
free(cookie);
return 0;
}