sl@0: /* 
sl@0:  * tclLoadAix.c --
sl@0:  *
sl@0:  *	This file implements the dlopen and dlsym APIs under the
sl@0:  *	AIX operating system, to enable the Tcl "load" command to
sl@0:  *	work.  This code was provided by Jens-Uwe Mager.
sl@0:  *
sl@0:  *	This file is subject to the following copyright notice, which is
sl@0:  *	different from the notice used elsewhere in Tcl.  The file has
sl@0:  *	been modified to incorporate the file dlfcn.h in-line.
sl@0:  *
sl@0:  *	Copyright (c) 1992,1993,1995,1996, Jens-Uwe Mager, Helios Software GmbH
sl@0:  *	Not derived from licensed software.
sl@0: 
sl@0:  *	Permission is granted to freely use, copy, modify, and redistribute
sl@0:  *	this software, provided that the author is not construed to be liable
sl@0:  *	for any results of using the software, alterations are clearly marked
sl@0:  *	as such, and this notice is not modified.
sl@0:  *
sl@0:  * RCS: @(#) $Id: tclLoadAix.c,v 1.3 1999/04/16 00:48:04 stanton Exp $
sl@0:  *
sl@0:  * Note:  this file has been altered from the original in a few
sl@0:  * ways in order to work properly with Tcl.
sl@0:  */
sl@0: 
sl@0: /*
sl@0:  * @(#)dlfcn.c	1.7 revision of 95/08/14  19:08:38
sl@0:  * This is an unpublished work copyright (c) 1992 HELIOS Software GmbH
sl@0:  * 30159 Hannover, Germany
sl@0:  */
sl@0: 
sl@0: #include <stdio.h>
sl@0: #include <errno.h>
sl@0: #include <string.h>
sl@0: #include <stdlib.h>
sl@0: #include <sys/types.h>
sl@0: #include <sys/ldr.h>
sl@0: #include <a.out.h>
sl@0: #include <ldfcn.h>
sl@0: #include "../compat/dlfcn.h"
sl@0: 
sl@0: /*
sl@0:  * We simulate dlopen() et al. through a call to load. Because AIX has
sl@0:  * no call to find an exported symbol we read the loader section of the
sl@0:  * loaded module and build a list of exported symbols and their virtual
sl@0:  * address.
sl@0:  */
sl@0: 
sl@0: typedef struct {
sl@0: 	char		*name;		/* the symbols's name */
sl@0: 	void		*addr;		/* its relocated virtual address */
sl@0: } Export, *ExportPtr;
sl@0: 
sl@0: /*
sl@0:  * xlC uses the following structure to list its constructors and
sl@0:  * destructors. This is gleaned from the output of munch.
sl@0:  */
sl@0: typedef struct {
sl@0: 	void (*init)(void);		/* call static constructors */
sl@0: 	void (*term)(void);		/* call static destructors */
sl@0: } Cdtor, *CdtorPtr;
sl@0: 
sl@0: /*
sl@0:  * The void * handle returned from dlopen is actually a ModulePtr.
sl@0:  */
sl@0: typedef struct Module {
sl@0: 	struct Module	*next;
sl@0: 	char		*name;		/* module name for refcounting */
sl@0: 	int		refCnt;		/* the number of references */
sl@0: 	void		*entry;		/* entry point from load */
sl@0: 	struct dl_info	*info;		/* optional init/terminate functions */
sl@0: 	CdtorPtr	cdtors;		/* optional C++ constructors */
sl@0: 	int		nExports;	/* the number of exports found */
sl@0: 	ExportPtr	exports;	/* the array of exports */
sl@0: } Module, *ModulePtr;
sl@0: 
sl@0: /*
sl@0:  * We keep a list of all loaded modules to be able to call the fini
sl@0:  * handlers and destructors at atexit() time.
sl@0:  */
sl@0: static ModulePtr modList;
sl@0: 
sl@0: /*
sl@0:  * The last error from one of the dl* routines is kept in static
sl@0:  * variables here. Each error is returned only once to the caller.
sl@0:  */
sl@0: static char errbuf[BUFSIZ];
sl@0: static int errvalid;
sl@0: 
sl@0: static void caterr(char *);
sl@0: static int readExports(ModulePtr);
sl@0: static void terminate(void);
sl@0: static void *findMain(void);
sl@0: 
sl@0: VOID *dlopen(const char *path, int mode)
sl@0: {
sl@0: 	register ModulePtr mp;
sl@0: 	static void *mainModule;
sl@0: 
sl@0: 	/*
sl@0: 	 * Upon the first call register a terminate handler that will
sl@0: 	 * close all libraries. Also get a reference to the main module
sl@0: 	 * for use with loadbind.
sl@0: 	 */
sl@0: 	if (!mainModule) {
sl@0: 		if ((mainModule = findMain()) == NULL)
sl@0: 			return NULL;
sl@0: 		atexit(terminate);
sl@0: 	}
sl@0: 	/*
sl@0: 	 * Scan the list of modules if we have the module already loaded.
sl@0: 	 */
sl@0: 	for (mp = modList; mp; mp = mp->next)
sl@0: 		if (strcmp(mp->name, path) == 0) {
sl@0: 			mp->refCnt++;
sl@0: 			return (VOID *) mp;
sl@0: 		}
sl@0: 	if ((mp = (ModulePtr)calloc(1, sizeof(*mp))) == NULL) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "calloc: ");
sl@0: 		strcat(errbuf, strerror(errno));
sl@0: 		return (VOID *) NULL;
sl@0: 	}
sl@0: 	mp->name = malloc((unsigned) (strlen(path) + 1));
sl@0: 	strcpy(mp->name, path);
sl@0: 	/*
sl@0: 	 * load should be declared load(const char *...). Thus we
sl@0: 	 * cast the path to a normal char *. Ugly.
sl@0: 	 */
sl@0: 	if ((mp->entry = (void *)load((char *)path, L_NOAUTODEFER, NULL)) == NULL) {
sl@0: 		free(mp->name);
sl@0: 		free(mp);
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "dlopen: ");
sl@0: 		strcat(errbuf, path);
sl@0: 		strcat(errbuf, ": ");
sl@0: 		/*
sl@0: 		 * If AIX says the file is not executable, the error
sl@0: 		 * can be further described by querying the loader about
sl@0: 		 * the last error.
sl@0: 		 */
sl@0: 		if (errno == ENOEXEC) {
sl@0: 			char *tmp[BUFSIZ/sizeof(char *)];
sl@0: 			if (loadquery(L_GETMESSAGES, tmp, sizeof(tmp)) == -1)
sl@0: 				strcpy(errbuf, strerror(errno));
sl@0: 			else {
sl@0: 				char **p;
sl@0: 				for (p = tmp; *p; p++)
sl@0: 					caterr(*p);
sl@0: 			}
sl@0: 		} else
sl@0: 			strcat(errbuf, strerror(errno));
sl@0: 		return (VOID *) NULL;
sl@0: 	}
sl@0: 	mp->refCnt = 1;
sl@0: 	mp->next = modList;
sl@0: 	modList = mp;
sl@0: 	if (loadbind(0, mainModule, mp->entry) == -1) {
sl@0: 		dlclose(mp);
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "loadbind: ");
sl@0: 		strcat(errbuf, strerror(errno));
sl@0: 		return (VOID *) NULL;
sl@0: 	}
sl@0: 	/*
sl@0: 	 * If the user wants global binding, loadbind against all other
sl@0: 	 * loaded modules.
sl@0: 	 */
sl@0: 	if (mode & RTLD_GLOBAL) {
sl@0: 		register ModulePtr mp1;
sl@0: 		for (mp1 = mp->next; mp1; mp1 = mp1->next)
sl@0: 			if (loadbind(0, mp1->entry, mp->entry) == -1) {
sl@0: 				dlclose(mp);
sl@0: 				errvalid++;
sl@0: 				strcpy(errbuf, "loadbind: ");
sl@0: 				strcat(errbuf, strerror(errno));
sl@0: 				return (VOID *) NULL;
sl@0: 			}
sl@0: 	}
sl@0: 	if (readExports(mp) == -1) {
sl@0: 		dlclose(mp);
sl@0: 		return (VOID *) NULL;
sl@0: 	}
sl@0: 	/*
sl@0: 	 * If there is a dl_info structure, call the init function.
sl@0: 	 */
sl@0: 	if (mp->info = (struct dl_info *)dlsym(mp, "dl_info")) {
sl@0: 		if (mp->info->init)
sl@0: 			(*mp->info->init)();
sl@0: 	} else
sl@0: 		errvalid = 0;
sl@0: 	/*
sl@0: 	 * If the shared object was compiled using xlC we will need
sl@0: 	 * to call static constructors (and later on dlclose destructors).
sl@0: 	 */
sl@0: 	if (mp->cdtors = (CdtorPtr)dlsym(mp, "__cdtors")) {
sl@0: 		while (mp->cdtors->init) {
sl@0: 			(*mp->cdtors->init)();
sl@0: 			mp->cdtors++;
sl@0: 		}
sl@0: 	} else
sl@0: 		errvalid = 0;
sl@0: 	return (VOID *) mp;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  * Attempt to decipher an AIX loader error message and append it
sl@0:  * to our static error message buffer.
sl@0:  */
sl@0: static void caterr(char *s)
sl@0: {
sl@0: 	register char *p = s;
sl@0: 
sl@0: 	while (*p >= '0' && *p <= '9')
sl@0: 		p++;
sl@0: 	switch(atoi(s)) {		/* INTL: "C", UTF safe. */
sl@0: 	case L_ERROR_TOOMANY:
sl@0: 		strcat(errbuf, "to many errors");
sl@0: 		break;
sl@0: 	case L_ERROR_NOLIB:
sl@0: 		strcat(errbuf, "can't load library");
sl@0: 		strcat(errbuf, p);
sl@0: 		break;
sl@0: 	case L_ERROR_UNDEF:
sl@0: 		strcat(errbuf, "can't find symbol");
sl@0: 		strcat(errbuf, p);
sl@0: 		break;
sl@0: 	case L_ERROR_RLDBAD:
sl@0: 		strcat(errbuf, "bad RLD");
sl@0: 		strcat(errbuf, p);
sl@0: 		break;
sl@0: 	case L_ERROR_FORMAT:
sl@0: 		strcat(errbuf, "bad exec format in");
sl@0: 		strcat(errbuf, p);
sl@0: 		break;
sl@0: 	case L_ERROR_ERRNO:
sl@0: 		strcat(errbuf, strerror(atoi(++p)));	/* INTL: "C", UTF safe. */
sl@0: 		break;
sl@0: 	default:
sl@0: 		strcat(errbuf, s);
sl@0: 		break;
sl@0: 	}
sl@0: }
sl@0: 
sl@0: VOID *dlsym(void *handle, const char *symbol)
sl@0: {
sl@0: 	register ModulePtr mp = (ModulePtr)handle;
sl@0: 	register ExportPtr ep;
sl@0: 	register int i;
sl@0: 
sl@0: 	/*
sl@0: 	 * Could speed up the search, but I assume that one assigns
sl@0: 	 * the result to function pointers anyways.
sl@0: 	 */
sl@0: 	for (ep = mp->exports, i = mp->nExports; i; i--, ep++)
sl@0: 		if (strcmp(ep->name, symbol) == 0)
sl@0: 			return ep->addr;
sl@0: 	errvalid++;
sl@0: 	strcpy(errbuf, "dlsym: undefined symbol ");
sl@0: 	strcat(errbuf, symbol);
sl@0: 	return NULL;
sl@0: }
sl@0: 
sl@0: char *dlerror(void)
sl@0: {
sl@0: 	if (errvalid) {
sl@0: 		errvalid = 0;
sl@0: 		return errbuf;
sl@0: 	}
sl@0: 	return NULL;
sl@0: }
sl@0: 
sl@0: int dlclose(void *handle)
sl@0: {
sl@0: 	register ModulePtr mp = (ModulePtr)handle;
sl@0: 	int result;
sl@0: 	register ModulePtr mp1;
sl@0: 
sl@0: 	if (--mp->refCnt > 0)
sl@0: 		return 0;
sl@0: 	if (mp->info && mp->info->fini)
sl@0: 		(*mp->info->fini)();
sl@0: 	if (mp->cdtors)
sl@0: 		while (mp->cdtors->term) {
sl@0: 			(*mp->cdtors->term)();
sl@0: 			mp->cdtors++;
sl@0: 		}
sl@0: 	result = unload(mp->entry);
sl@0: 	if (result == -1) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, strerror(errno));
sl@0: 	}
sl@0: 	if (mp->exports) {
sl@0: 		register ExportPtr ep;
sl@0: 		register int i;
sl@0: 		for (ep = mp->exports, i = mp->nExports; i; i--, ep++)
sl@0: 			if (ep->name)
sl@0: 				free(ep->name);
sl@0: 		free(mp->exports);
sl@0: 	}
sl@0: 	if (mp == modList)
sl@0: 		modList = mp->next;
sl@0: 	else {
sl@0: 		for (mp1 = modList; mp1; mp1 = mp1->next)
sl@0: 			if (mp1->next == mp) {
sl@0: 				mp1->next = mp->next;
sl@0: 				break;
sl@0: 			}
sl@0: 	}
sl@0: 	free(mp->name);
sl@0: 	free(mp);
sl@0: 	return result;
sl@0: }
sl@0: 
sl@0: static void terminate(void)
sl@0: {
sl@0: 	while (modList)
sl@0: 		dlclose(modList);
sl@0: }
sl@0: 
sl@0: /*
sl@0:  * Build the export table from the XCOFF .loader section.
sl@0:  */
sl@0: static int readExports(ModulePtr mp)
sl@0: {
sl@0: 	LDFILE *ldp = NULL;
sl@0: 	SCNHDR sh, shdata;
sl@0: 	LDHDR *lhp;
sl@0: 	char *ldbuf;
sl@0: 	LDSYM *ls;
sl@0: 	int i;
sl@0: 	ExportPtr ep;
sl@0: 
sl@0: 	if ((ldp = ldopen(mp->name, ldp)) == NULL) {
sl@0: 		struct ld_info *lp;
sl@0: 		char *buf;
sl@0: 		int size = 4*1024;
sl@0: 		if (errno != ENOENT) {
sl@0: 			errvalid++;
sl@0: 			strcpy(errbuf, "readExports: ");
sl@0: 			strcat(errbuf, strerror(errno));
sl@0: 			return -1;
sl@0: 		}
sl@0: 		/*
sl@0: 		 * The module might be loaded due to the LIBPATH
sl@0: 		 * environment variable. Search for the loaded
sl@0: 		 * module using L_GETINFO.
sl@0: 		 */
sl@0: 		if ((buf = malloc(size)) == NULL) {
sl@0: 			errvalid++;
sl@0: 			strcpy(errbuf, "readExports: ");
sl@0: 			strcat(errbuf, strerror(errno));
sl@0: 			return -1;
sl@0: 		}
sl@0: 		while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM) {
sl@0: 			free(buf);
sl@0: 			size += 4*1024;
sl@0: 			if ((buf = malloc(size)) == NULL) {
sl@0: 				errvalid++;
sl@0: 				strcpy(errbuf, "readExports: ");
sl@0: 				strcat(errbuf, strerror(errno));
sl@0: 				return -1;
sl@0: 			}
sl@0: 		}
sl@0: 		if (i == -1) {
sl@0: 			errvalid++;
sl@0: 			strcpy(errbuf, "readExports: ");
sl@0: 			strcat(errbuf, strerror(errno));
sl@0: 			free(buf);
sl@0: 			return -1;
sl@0: 		}
sl@0: 		/*
sl@0: 		 * Traverse the list of loaded modules. The entry point
sl@0: 		 * returned by load() does actually point to the data
sl@0: 		 * segment origin.
sl@0: 		 */
sl@0: 		lp = (struct ld_info *)buf;
sl@0: 		while (lp) {
sl@0: 			if (lp->ldinfo_dataorg == mp->entry) {
sl@0: 				ldp = ldopen(lp->ldinfo_filename, ldp);
sl@0: 				break;
sl@0: 			}
sl@0: 			if (lp->ldinfo_next == 0)
sl@0: 				lp = NULL;
sl@0: 			else
sl@0: 				lp = (struct ld_info *)((char *)lp + lp->ldinfo_next);
sl@0: 		}
sl@0: 		free(buf);
sl@0: 		if (!ldp) {
sl@0: 			errvalid++;
sl@0: 			strcpy(errbuf, "readExports: ");
sl@0: 			strcat(errbuf, strerror(errno));
sl@0: 			return -1;
sl@0: 		}
sl@0: 	}
sl@0: 	if (TYPE(ldp) != U802TOCMAGIC) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "readExports: bad magic");
sl@0: 		while(ldclose(ldp) == FAILURE)
sl@0: 			;
sl@0: 		return -1;
sl@0: 	}
sl@0: 	/*
sl@0: 	 * Get the padding for the data section. This is needed for
sl@0: 	 * AIX 4.1 compilers. This is used when building the final
sl@0: 	 * function pointer to the exported symbol.
sl@0: 	 */
sl@0: 	if (ldnshread(ldp, _DATA, &shdata) != SUCCESS) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "readExports: cannot read data section header");
sl@0: 		while(ldclose(ldp) == FAILURE)
sl@0: 			;
sl@0: 		return -1;
sl@0: 	}
sl@0: 	if (ldnshread(ldp, _LOADER, &sh) != SUCCESS) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "readExports: cannot read loader section header");
sl@0: 		while(ldclose(ldp) == FAILURE)
sl@0: 			;
sl@0: 		return -1;
sl@0: 	}
sl@0: 	/*
sl@0: 	 * We read the complete loader section in one chunk, this makes
sl@0: 	 * finding long symbol names residing in the string table easier.
sl@0: 	 */
sl@0: 	if ((ldbuf = (char *)malloc(sh.s_size)) == NULL) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "readExports: ");
sl@0: 		strcat(errbuf, strerror(errno));
sl@0: 		while(ldclose(ldp) == FAILURE)
sl@0: 			;
sl@0: 		return -1;
sl@0: 	}
sl@0: 	if (FSEEK(ldp, sh.s_scnptr, BEGINNING) != OKFSEEK) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "readExports: cannot seek to loader section");
sl@0: 		free(ldbuf);
sl@0: 		while(ldclose(ldp) == FAILURE)
sl@0: 			;
sl@0: 		return -1;
sl@0: 	}
sl@0: 	if (FREAD(ldbuf, sh.s_size, 1, ldp) != 1) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "readExports: cannot read loader section");
sl@0: 		free(ldbuf);
sl@0: 		while(ldclose(ldp) == FAILURE)
sl@0: 			;
sl@0: 		return -1;
sl@0: 	}
sl@0: 	lhp = (LDHDR *)ldbuf;
sl@0: 	ls = (LDSYM *)(ldbuf+LDHDRSZ);
sl@0: 	/*
sl@0: 	 * Count the number of exports to include in our export table.
sl@0: 	 */
sl@0: 	for (i = lhp->l_nsyms; i; i--, ls++) {
sl@0: 		if (!LDR_EXPORT(*ls))
sl@0: 			continue;
sl@0: 		mp->nExports++;
sl@0: 	}
sl@0: 	if ((mp->exports = (ExportPtr)calloc(mp->nExports, sizeof(*mp->exports))) == NULL) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "readExports: ");
sl@0: 		strcat(errbuf, strerror(errno));
sl@0: 		free(ldbuf);
sl@0: 		while(ldclose(ldp) == FAILURE)
sl@0: 			;
sl@0: 		return -1;
sl@0: 	}
sl@0: 	/*
sl@0: 	 * Fill in the export table. All entries are relative to
sl@0: 	 * the entry point we got from load.
sl@0: 	 */
sl@0: 	ep = mp->exports;
sl@0: 	ls = (LDSYM *)(ldbuf+LDHDRSZ);
sl@0: 	for (i = lhp->l_nsyms; i; i--, ls++) {
sl@0: 		char *symname;
sl@0: 		char tmpsym[SYMNMLEN+1];
sl@0: 		if (!LDR_EXPORT(*ls))
sl@0: 			continue;
sl@0: 		if (ls->l_zeroes == 0)
sl@0: 			symname = ls->l_offset+lhp->l_stoff+ldbuf;
sl@0: 		else {
sl@0: 			/*
sl@0: 			 * The l_name member is not zero terminated, we
sl@0: 			 * must copy the first SYMNMLEN chars and make
sl@0: 			 * sure we have a zero byte at the end.
sl@0: 			 */
sl@0: 			strncpy(tmpsym, ls->l_name, SYMNMLEN);
sl@0: 			tmpsym[SYMNMLEN] = '\0';
sl@0: 			symname = tmpsym;
sl@0: 		}
sl@0: 		ep->name = malloc((unsigned) (strlen(symname) + 1));
sl@0: 		strcpy(ep->name, symname);
sl@0: 		ep->addr = (void *)((unsigned long)mp->entry +
sl@0: 					ls->l_value - shdata.s_vaddr);
sl@0: 		ep++;
sl@0: 	}
sl@0: 	free(ldbuf);
sl@0: 	while(ldclose(ldp) == FAILURE)
sl@0: 		;
sl@0: 	return 0;
sl@0: }
sl@0: 
sl@0: /*
sl@0:  * Find the main modules entry point. This is used as export pointer
sl@0:  * for loadbind() to be able to resolve references to the main part.
sl@0:  */
sl@0: static void * findMain(void)
sl@0: {
sl@0: 	struct ld_info *lp;
sl@0: 	char *buf;
sl@0: 	int size = 4*1024;
sl@0: 	int i;
sl@0: 	void *ret;
sl@0: 
sl@0: 	if ((buf = malloc(size)) == NULL) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "findMain: ");
sl@0: 		strcat(errbuf, strerror(errno));
sl@0: 		return NULL;
sl@0: 	}
sl@0: 	while ((i = loadquery(L_GETINFO, buf, size)) == -1 && errno == ENOMEM) {
sl@0: 		free(buf);
sl@0: 		size += 4*1024;
sl@0: 		if ((buf = malloc(size)) == NULL) {
sl@0: 			errvalid++;
sl@0: 			strcpy(errbuf, "findMain: ");
sl@0: 			strcat(errbuf, strerror(errno));
sl@0: 			return NULL;
sl@0: 		}
sl@0: 	}
sl@0: 	if (i == -1) {
sl@0: 		errvalid++;
sl@0: 		strcpy(errbuf, "findMain: ");
sl@0: 		strcat(errbuf, strerror(errno));
sl@0: 		free(buf);
sl@0: 		return NULL;
sl@0: 	}
sl@0: 	/*
sl@0: 	 * The first entry is the main module. The entry point
sl@0: 	 * returned by load() does actually point to the data
sl@0: 	 * segment origin.
sl@0: 	 */
sl@0: 	lp = (struct ld_info *)buf;
sl@0: 	ret = lp->ldinfo_dataorg;
sl@0: 	free(buf);
sl@0: 	return ret;
sl@0: }
sl@0: