pkg_elf.c

/*
 * Copyright (c) 2011-2012 Baptiste Daroussin <bapt@FreeBSD.org>
 * Copyright (c) 2012 Matthew Seaman <matthew@FreeBSD.org>
 * 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
 *    in this position and unchanged.
 * 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.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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(S) 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.
 */

#include <sys/endian.h>
#include <sys/types.h>
#ifndef BUNDLED_LIBELF
#include <sys/elf_common.h>
#endif
#include <sys/stat.h>

#include <assert.h>
#include <ctype.h>
#include <dlfcn.h>
#include <elf-hints.h>
#include <err.h>
#include <fcntl.h>
#include <gelf.h>
#ifndef BUNDLED_LIBELF
#include <link.h>
#endif
#include <stdbool.h>
#include <string.h>
#include <unistd.h>

#include "pkg.h"
#include "private/pkg.h"
#include "private/event.h"
#include "private/elf_tables.h"
#include "private/ldconfig.h"

/* FFR: when we support installing a 32bit package on a 64bit host */
#define _PATH_ELF32_HINTS       "/var/run/ld-elf32.so.hints"

static int
filter_system_shlibs(const char *name, char *path, size_t pathlen)
{
	const char *shlib_path;

	shlib_path = shlib_list_find_by_name(name);
	if (shlib_path == NULL) {
		return (EPKG_FATAL);
	}

	/* match /lib, /lib32, /usr/lib and /usr/lib32 */
	if (strncmp(shlib_path, "/lib", 4) == 0 ||
	    strncmp(shlib_path, "/usr/lib", 7) == 0)
		return (EPKG_END); /* ignore libs from base */

	if (path != NULL)
		strncpy(path, shlib_path, pathlen);

	return (EPKG_OK);
} 

/* Callback functions to process the shlib data */

/* ARGSUSED */
static int
do_nothing(__unused void *actdata, __unused struct pkg *pkg,
	   __unused const char *name)
{
	return (EPKG_OK);
}

/* ARGSUSED */
static int
add_shlibs_to_pkg(__unused void *actdata, struct pkg *pkg, const char *name)
{
	switch(filter_system_shlibs(name, NULL, 0)) {
	case EPKG_OK:		/* A non-system library */
		pkg_addshlib(pkg, name);
		return (EPKG_OK);
	case EPKG_END:		/* A system library */
		return (EPKG_OK);
	default:
		warnx("(%s-%s) shared library %s not found", pkg_name(pkg),
		      pkg_version(pkg), name);
		return (EPKG_FATAL);
	}
}

static int
test_depends(void *actdata, struct pkg *pkg, const char *name)
{
	struct pkgdb *db = actdata;
	struct pkg_dep *dep = NULL;
	struct pkgdb_it *it = NULL;
	struct pkg *d;
	const char *deporigin, *depname, *depversion;
	char pathbuf[MAXPATHLEN];
	bool found;
	bool shlibs = false;

	assert(db != NULL);

	pkg_config_bool(PKG_CONFIG_SHLIBS, &shlibs);

	switch(filter_system_shlibs(name, pathbuf, sizeof(pathbuf))) {
	case EPKG_OK:		/* A non-system library */
		break;
	case EPKG_END:		/* A system library */
		return (EPKG_OK);
	default:
		warnx("(%s-%s) shared library %s not found", pkg_name(pkg),
		      pkg_version(pkg), name);
		return (EPKG_FATAL);
	}

	if (shlibs)
		pkg_addshlib(pkg, name);

	if ((it = pkgdb_query_which(db, pathbuf)) == NULL)
		return (EPKG_OK);

	d = NULL;
	if (pkgdb_it_next(it, &d, PKG_LOAD_BASIC) == EPKG_OK) {
		found = false;
		pkg_get(d, PKG_ORIGIN, &deporigin, PKG_NAME, &depname,
		    PKG_VERSION, &depversion);

		dep = NULL;
		found = false;
		while (pkg_deps(pkg, &dep) == EPKG_OK) {
			if (strcmp(pkg_dep_origin(dep), deporigin) == 0) {
				found = true;
				break;
			}
		}
		if (!found) {
			pkg_emit_error("adding forgotten depends (%s): %s-%s",
					pathbuf, depname, depversion);
			pkg_adddep(pkg, depname, deporigin, depversion);
		}
		pkg_free(d);
	}

	pkgdb_it_free(it);
	return (EPKG_OK);
}

static int
analyse_elf(struct pkg *pkg, const char *fpath, 
    int (action)(void *, struct pkg *, const char *), void *actdata)
{
	Elf *e = NULL;
	GElf_Ehdr elfhdr;
	Elf_Scn *scn = NULL;
	Elf_Scn *note = NULL;
	Elf_Scn *dynamic = NULL;
	GElf_Shdr shdr;
	Elf_Data *data;
	GElf_Dyn *dyn, dyn_mem;
	struct stat sb;
	int ret = EPKG_OK;

	size_t numdyn;
	size_t sh_link;
	size_t dynidx;
	const char *osname;

	bool shlibs = false;
	bool autodeps = false;
	bool developer = false;

	pkg_config_bool(PKG_CONFIG_AUTODEPS, &autodeps);
	pkg_config_bool(PKG_CONFIG_SHLIBS, &shlibs);
	pkg_config_bool(PKG_CONFIG_DEVELOPER_MODE, &developer);

	int fd;

	if ((fd = open(fpath, O_RDONLY, 0)) < 0) {
		return (EPKG_FATAL);
	}
	if (fstat(fd, &sb) != 0)
		pkg_emit_errno("fstat() failed for %s", fpath);
	/* ignore empty files and non regular files */
	if (sb.st_size == 0 || !S_ISREG(sb.st_mode)) {
		ret = EPKG_END; /* Empty file: no results */
		goto cleanup;
	}

	if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
		ret = EPKG_FATAL;
		pkg_emit_error("elf_begin() for %s failed: %s", fpath,
		    elf_errmsg(-1));
		goto cleanup;
	}

	if (elf_kind(e) != ELF_K_ELF) {
		close(fd);
		return (EPKG_END); /* Not an elf file: no results */
	}

	if (developer)
		pkg->flags |= PKG_CONTAINS_ELF_OBJECTS;

	if (!autodeps && !shlibs) {
	   ret = EPKG_OK;
	   goto cleanup;
	}

	if (gelf_getehdr(e, &elfhdr) == NULL) {
		ret = EPKG_FATAL;
		pkg_emit_error("getehdr() failed: %s.", elf_errmsg(-1));
		goto cleanup;
	}

	while ((scn = elf_nextscn(e, scn)) != NULL) {
		if (gelf_getshdr(scn, &shdr) != &shdr) {
			ret = EPKG_FATAL;
			pkg_emit_error("getshdr() for %s failed: %s", fpath,
			    elf_errmsg(-1));
			goto cleanup;
		}
		switch (shdr.sh_type) {
		case SHT_NOTE:
			note = scn;
			break;
		case SHT_DYNAMIC:
			dynamic = scn;
			sh_link = shdr.sh_link;
			numdyn = shdr.sh_size / shdr.sh_entsize;
			break;
		}

		if (note != NULL && dynamic != NULL)
			break;
	}

	/*
	 * note == NULL usually means a shared object for use with dlopen(3)
	 * dynamic == NULL means not a dynamically linked elf
	 */
	if (dynamic == NULL) {
		ret = EPKG_END;
		goto cleanup; /* not a dynamically linked elf: no results */
	}

	if (note != NULL) {
		data = elf_getdata(note, NULL);
		osname = (const char *) data->d_buf + sizeof(Elf_Note);
		if (strncasecmp(osname, "freebsd", sizeof("freebsd")) != 0) {
			ret = EPKG_END;	/* Foreign (probably linux) ELF object */
			goto cleanup;
		}
	} else {
		if (elfhdr.e_ident[EI_OSABI] != ELFOSABI_FREEBSD) {
			ret = EPKG_END;
			goto cleanup;
		}
	}

	data = elf_getdata(dynamic, NULL);

	/* First, scan through the data from the .dynamic section to
	   find any RPATH or RUNPATH settings.  These are colon
	   separated paths to prepend to the ld.so search paths from
	   the ELF hints file.  These always seem to come right after
	   the NEEDED entries */

	rpath_list_init();
	for (dynidx = 0; dynidx < numdyn; dynidx++) {
		if ((dyn = gelf_getdyn(data, dynidx, &dyn_mem)) == NULL) {
			ret = EPKG_FATAL;
			pkg_emit_error("getdyn() failed for %s: %s", fpath,
			    elf_errmsg(-1));
			goto cleanup;
		}

		if (dyn->d_tag != DT_RPATH && dyn->d_tag != DT_RUNPATH)
			continue;

		shlib_list_from_rpath(elf_strptr(e, sh_link, dyn->d_un.d_val));
		break;
	}

	/* Now find all of the NEEDED shared libraries */

	for (dynidx = 0; dynidx < numdyn; dynidx++) {
		if ((dyn = gelf_getdyn(data, dynidx, &dyn_mem)) == NULL) {
			ret = EPKG_FATAL;
			pkg_emit_error("getdyn() failed for %s: %s", fpath,
			    elf_errmsg(-1));
			goto cleanup;
		}

		if (dyn->d_tag != DT_NEEDED)
			continue;

		action(actdata, pkg, elf_strptr(e, sh_link, dyn->d_un.d_val));
	}

cleanup:
	rpath_list_free();

	if (e != NULL)
		elf_end(e);
	close(fd);

	return (ret);
}

static int
analyse_fpath(struct pkg *pkg, const char *fpath)
{
	const char *dot;

	dot = strrchr(fpath, '.');

	if (dot == NULL)	/* No extension */
		return (EPKG_OK);

	if (dot[1] == 'a' && dot[2] == '\0')
		pkg->flags |= PKG_CONTAINS_STATIC_LIBS;

	if ((dot[1] == 'l' && dot[2] == 'a' && dot[3] == '\0') ||
	    (dot[1] == 'h' && dot[2] == '\0'))
		pkg->flags |= PKG_CONTAINS_H_OR_LA;

	return (EPKG_OK);
}

int
pkg_analyse_files(struct pkgdb *db, struct pkg *pkg)
{
	struct pkg_file *file = NULL;
	int ret = EPKG_OK;
	const char *fpath;
	bool shlibs = false;
	bool autodeps = false;
	bool developer = false;
	int (*action)(void *, struct pkg *, const char *);

	pkg_config_bool(PKG_CONFIG_SHLIBS, &shlibs);
	pkg_config_bool(PKG_CONFIG_AUTODEPS, &autodeps);
	pkg_config_bool(PKG_CONFIG_DEVELOPER_MODE, &developer);

	if (!autodeps && !shlibs && !developer)
		return (EPKG_OK);

	if (elf_version(EV_CURRENT) == EV_NONE)
		return (EPKG_FATAL);

	if (autodeps)
		action = test_depends;
	else if (shlibs)
		action = add_shlibs_to_pkg;
	else
		action = do_nothing;

	if (autodeps || shlibs) {
		shlib_list_init();

		ret = shlib_list_from_elf_hints(_PATH_ELF_HINTS);
		if (ret != EPKG_OK)
			goto cleanup;
	}

	/* Assume no architecture dependence, for contradiction */
	if (developer)
		pkg->flags &= ~(PKG_CONTAINS_ELF_OBJECTS |
				PKG_CONTAINS_STATIC_LIBS |
				PKG_CONTAINS_H_OR_LA);

	while (pkg_files(pkg, &file) == EPKG_OK) {
		fpath = pkg_file_path(file);
		ret = analyse_elf(pkg, fpath, action, db);
		if (developer) {
			if (ret != EPKG_OK && ret != EPKG_END)
				goto cleanup;
			analyse_fpath(pkg, fpath);
		}
	}

	ret = EPKG_OK;

cleanup:
	if (autodeps || shlibs)
		shlib_list_free();

	return (ret);
}

int
pkg_register_shlibs(struct pkg *pkg)
{
	struct pkg_file        *file = NULL;
	bool			shlibs;

	pkg_config_bool(PKG_CONFIG_SHLIBS, &shlibs);

	pkg_list_free(pkg, PKG_SHLIBS);

	if (!shlibs)
		return (EPKG_OK);

	if (elf_version(EV_CURRENT) == EV_NONE)
		return (EPKG_FATAL);

	shlib_list_init();
	if (shlib_list_from_elf_hints(_PATH_ELF_HINTS) != EPKG_OK) {
		shlib_list_free();
		return (EPKG_FATAL);
	}

	while(pkg_files(pkg, &file) == EPKG_OK)
		analyse_elf(pkg, pkg_file_path(file), add_shlibs_to_pkg, NULL);

	shlib_list_free();
	return (EPKG_OK);
}

static const char *
elf_corres_to_string(struct _elf_corres* m, int e)
{
	int i = 0;

	for (i = 0; m[i].string != NULL; i++)
		if (m[i].elf_nb == e)
			return (m[i].string);

	return ("unknown");
}

int
pkg_get_myarch(char *dest, size_t sz)
{
	Elf *elf = NULL;
	GElf_Ehdr elfhdr;
	GElf_Shdr shdr;
	Elf_Data *data;
	Elf_Note note;
	Elf_Scn *scn = NULL;
	int fd;
	char *src = NULL;
	char *osname;
	uint32_t version = 0;
	int ret = EPKG_OK;
	int i;
	const char *abi, *endian_corres_str, *wordsize_corres_str;

	if (elf_version(EV_CURRENT) == EV_NONE) {
		pkg_emit_error("ELF library initialization failed: %s",
		    elf_errmsg(-1));
		return (EPKG_FATAL);
	}

	if ((fd = open("/bin/sh", O_RDONLY)) < 0) {
		pkg_emit_errno("open", "/bin/sh");
		snprintf(dest, sz, "%s", "unknown");
		return (EPKG_FATAL);
	}

	if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
		ret = EPKG_FATAL;
		pkg_emit_error("elf_begin() failed: %s.", elf_errmsg(-1));
		goto cleanup;
	}

	if (gelf_getehdr(elf, &elfhdr) == NULL) {
		ret = EPKG_FATAL;
		pkg_emit_error("getehdr() failed: %s.", elf_errmsg(-1));
		goto cleanup;
	}

	while ((scn = elf_nextscn(elf, scn)) != NULL) {
		if (gelf_getshdr(scn, &shdr) != &shdr) {
			ret = EPKG_FATAL;
			pkg_emit_error("getshdr() failed: %s.", elf_errmsg(-1));
			goto cleanup;
		}

		if (shdr.sh_type == SHT_NOTE)
			break;
	}

	if (scn == NULL) {
		ret = EPKG_FATAL;
		pkg_emit_error("fail to get the note section");
		goto cleanup;
	}

	data = elf_getdata(scn, NULL);
	src = data->d_buf;
	while (1) {
		memcpy(&note, src, sizeof(Elf_Note));
		src += sizeof(Elf_Note);
		if (note.n_type == NT_VERSION)
			break;
		src += note.n_namesz + note.n_descsz;
	}
	osname = src;
	src += note.n_namesz;
	if (elfhdr.e_ident[EI_DATA] == ELFDATA2MSB)
		version = be32dec(src);
	else
		version = le32dec(src);

	for (i = 0; osname[i] != '\0'; i++)
		osname[i] = (char)tolower(osname[i]);

	wordsize_corres_str = elf_corres_to_string(wordsize_corres,
	    (int)elfhdr.e_ident[EI_CLASS]);

	snprintf(dest, sz, "%s:%d:%s:%s",
	    osname, version / 100000,
	    elf_corres_to_string(mach_corres, (int) elfhdr.e_machine),
	    wordsize_corres_str);

	switch (elfhdr.e_machine) {
	case EM_ARM:
		endian_corres_str = elf_corres_to_string(endian_corres,
		    (int)elfhdr.e_ident[EI_DATA]);

		snprintf(dest + strlen(dest), sz - strlen(dest), ":%s:%s:%s",
		    endian_corres_str,
		    (elfhdr.e_flags & EF_ARM_NEW_ABI) > 0 ? "eabi" : "oabi",
		    (elfhdr.e_flags & EF_ARM_VFP_FLOAT) > 0 ? "softfp" : "vfp");
		break;
	case EM_MIPS:
		/*
		 * this is taken from binutils sources:
		 * include/elf/mips.h
		 * mapping is figured out from binutils:
		 * gas/config/tc-mips.c
		 */
		switch (elfhdr.e_flags & EF_MIPS_ABI) {
			case E_MIPS_ABI_O32:
				abi = "o32";
				break;
			case E_MIPS_ABI_N32:
				abi = "n32";
				break;
			default:
				if (elfhdr.e_ident[EI_DATA] == ELFCLASS32)
					abi = "o32";
				else if (elfhdr.e_ident[EI_DATA] == ELFCLASS64)
					abi = "n64";
				else
					abi = "unknown";
				break;
		}
		endian_corres_str = elf_corres_to_string(endian_corres,
		    (int)elfhdr.e_ident[EI_DATA]);

		snprintf(dest + strlen(dest), sz - strlen(dest), ":%s:%s",
		    endian_corres_str, abi);
		break;
	default:
		break;
	}

cleanup:
	if (elf != NULL)
		elf_end(elf);

	close(fd);
	return (ret);
}

int
pkg_suggest_arch(struct pkg *pkg, const char *arch, bool isdefault)
{
	bool iswildcard;

	iswildcard = (strchr(arch, 'c') != NULL);

	if (iswildcard && isdefault)
		pkg_emit_error("Configuration error: arch \"%s\" cannot use "
		    "wildcards as default", arch);

	if (pkg->flags & (PKG_CONTAINS_ELF_OBJECTS|PKG_CONTAINS_STATIC_LIBS)) {
		if (iswildcard) {
			/* Definitely has to be arch specific */
			pkg_emit_error("Error: arch \"%s\" -- package installs "
			    "architecture specific files", arch);
		}
	} else {
		if (pkg->flags & PKG_CONTAINS_H_OR_LA) {
			if (iswildcard) {
				/* Could well be arch specific */
				pkg_emit_error("Warning: arch \"%s\" -- package"
				    " installs C/C++ headers or libtool "
				    "files,\n**** which are often architecture "
				    "specific", arch);
			}
		} else {
			/* Might be arch independent */
			if (!iswildcard)
				pkg_emit_error("Notice: arch \"%s\" -- no "
				    "architecture specific files found:\n"
				    "**** could this package use a wildcard "
				    "architecture?", arch);
		}
	}
	return (EPKG_OK);
}