--- /dev/null
+/* Opening CTF files with BFD.
+ Copyright (C) 2019 Free Software Foundation, Inc.
+
+ This file is part of libctf.
+
+ libctf is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free
+ Software Foundation; either version 3, or (at your option) any later
+ version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; see the file COPYING. If not see
+ <http://www.gnu.org/licenses/>. */
+
+#include <ctf-impl.h>
+#include <stddef.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <elf.h>
+#include <bfd.h>
+
+#include "elf-bfd.h"
+
+/* Make a new struct ctf_archive_internal wrapper for a ctf_archive or a
+ ctf_file. Closes ARC and/or FP on error. Arrange to free the SYMSECT and
+ STRSECT interior on close. */
+
+static struct ctf_archive_internal *
+ctf_new_archive_internal (int is_archive, struct ctf_archive *arc,
+ ctf_file_t *fp, const ctf_sect_t *symsect,
+ const ctf_sect_t *strsect,
+ int *errp)
+{
+ struct ctf_archive_internal *arci;
+
+ if ((arci = calloc (1, sizeof (struct ctf_archive_internal))) == NULL)
+ {
+ if (is_archive)
+ ctf_arc_close_internal (arc);
+ else
+ ctf_file_close (fp);
+ return (ctf_set_open_errno (errp, errno));
+ }
+ arci->ctfi_is_archive = is_archive;
+ if (is_archive)
+ arci->ctfi_archive = arc;
+ else
+ arci->ctfi_file = fp;
+ if (symsect)
+ memcpy (&arci->ctfi_symsect, symsect, sizeof (struct ctf_sect));
+ if (strsect)
+ memcpy (&arci->ctfi_strsect, strsect, sizeof (struct ctf_sect));
+
+ return arci;
+}
+
+/* Free the BFD bits of a CTF file on ctf_file_close(). */
+
+static void
+ctf_bfdclose (struct ctf_archive_internal *arci)
+{
+ if (arci->ctfi_abfd != NULL)
+ if (!bfd_close_all_done (arci->ctfi_abfd))
+ ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error()));
+}
+
+/* Open a CTF file given the specified BFD. */
+
+ctf_archive_t *
+ctf_bfdopen (struct bfd *abfd, int *errp)
+{
+ ctf_archive_t *arc;
+ asection *ctf_asect;
+ bfd_byte *contents;
+ ctf_sect_t ctfsect;
+
+ libctf_init_debug();
+
+ if ((ctf_asect = bfd_get_section_by_name (abfd, _CTF_SECTION)) == NULL)
+ {
+ return (ctf_set_open_errno (errp, ECTF_NOCTFDATA));
+ }
+
+ if (!bfd_malloc_and_get_section (abfd, ctf_asect, &contents))
+ {
+ ctf_dprintf ("ctf_bfdopen(): cannot malloc CTF section: %s\n",
+ bfd_errmsg (bfd_get_error()));
+ return (ctf_set_open_errno (errp, ECTF_FMT));
+ }
+
+ ctfsect.cts_name = _CTF_SECTION;
+ ctfsect.cts_type = SHT_PROGBITS;
+ ctfsect.cts_flags = 0;
+ ctfsect.cts_entsize = 1;
+ ctfsect.cts_offset = 0;
+ ctfsect.cts_size = bfd_section_size (abfd, ctf_asect);
+ ctfsect.cts_data = contents;
+
+ if ((arc = ctf_bfdopen_ctfsect (abfd, &ctfsect, errp)) != NULL)
+ {
+ arc->ctfi_data = (void *) ctfsect.cts_data;
+ return arc;
+ }
+
+ free (contents);
+ return NULL; /* errno is set for us. */
+}
+
+/* Open a CTF file given the specified BFD and CTF section (which may contain a
+ CTF archive or a file). Takes ownership of the ctfsect, and frees it
+ later. */
+
+ctf_archive_t *
+ctf_bfdopen_ctfsect (struct bfd *abfd, const ctf_sect_t *ctfsect, int *errp)
+{
+ struct ctf_archive *arc = NULL;
+ ctf_archive_t *arci;
+ ctf_file_t *fp = NULL;
+ ctf_sect_t *symsectp = NULL;
+ ctf_sect_t *strsectp = NULL;
+ const char *bfderrstr = NULL;
+ int is_archive;
+
+ asection *sym_asect;
+ ctf_sect_t symsect, strsect;
+ /* TODO: handle SYMTAB_SHNDX. */
+
+ if ((sym_asect = bfd_section_from_elf_index (abfd,
+ elf_onesymtab (abfd))) != NULL)
+ {
+ Elf_Internal_Shdr *symhdr = &elf_symtab_hdr (abfd);
+ asection *str_asect = NULL;
+ bfd_byte *contents;
+
+ if (symhdr->sh_link != SHN_UNDEF &&
+ symhdr->sh_link <= elf_numsections (abfd))
+ str_asect = bfd_section_from_elf_index (abfd, symhdr->sh_link);
+
+ Elf_Internal_Shdr *strhdr = elf_elfsections (abfd)[symhdr->sh_link];
+
+ if (sym_asect && str_asect)
+ {
+ if (!bfd_malloc_and_get_section (abfd, str_asect, &contents))
+ {
+ bfderrstr = "Cannot malloc string table";
+ free (contents);
+ goto err;
+ }
+ strsect.cts_data = contents;
+ strsect.cts_name = (char *) strsect.cts_data + strhdr->sh_name;
+ strsect.cts_type = strhdr->sh_type;
+ strsect.cts_flags = strhdr->sh_flags;
+ strsect.cts_entsize = strhdr->sh_size;
+ strsect.cts_offset = strhdr->sh_offset;
+ strsectp = &strsect;
+
+ if (!bfd_malloc_and_get_section (abfd, sym_asect, &contents))
+ {
+ bfderrstr = "Cannot malloc symbol table";
+ free (contents);
+ goto err_free_str;
+ }
+
+ symsect.cts_name = (char *) strsect.cts_data + symhdr->sh_name;
+ symsect.cts_type = symhdr->sh_type;
+ symsect.cts_flags = symhdr->sh_flags;
+ symsect.cts_entsize = symhdr->sh_size;
+ symsect.cts_data = contents;
+ symsect.cts_offset = symhdr->sh_offset;
+ symsectp = &symsect;
+ }
+ }
+
+ if (ctfsect->cts_size > sizeof (uint64_t) &&
+ ((*(uint64_t *) ctfsect->cts_data) == CTFA_MAGIC))
+ {
+ is_archive = 1;
+ if ((arc = ctf_arc_bufopen ((void *) ctfsect->cts_data,
+ ctfsect->cts_size, errp)) == NULL)
+ goto err_free_sym;
+ }
+ else
+ {
+ is_archive = 0;
+ if ((fp = ctf_bufopen (ctfsect, symsectp, strsectp, errp)) == NULL)
+ {
+ ctf_dprintf ("ctf_internal_open(): cannot open CTF: %s\n",
+ ctf_errmsg (*errp));
+ goto err_free_sym;
+ }
+ }
+ arci = ctf_new_archive_internal (is_archive, arc, fp, symsectp, strsectp,
+ errp);
+
+ if (arci)
+ return arci;
+ err_free_sym:
+ free ((void *) symsect.cts_data);
+err_free_str:
+ free ((void *) strsect.cts_data);
+err: _libctf_unused_;
+ if (bfderrstr)
+ {
+ ctf_dprintf ("ctf_bfdopen(): %s: %s\n", bfderrstr,
+ bfd_errmsg (bfd_get_error()));
+ ctf_set_open_errno (errp, ECTF_FMT);
+ }
+ return NULL;
+}
+
+/* Open the specified file descriptor and return a pointer to a CTF archive that
+ contains one or more CTF containers. The file can be an ELF file, a raw CTF
+ file, or a CTF archive. The caller is responsible for closing the file
+ descriptor when it is no longer needed. If this is an ELF file, TARGET, if
+ non-NULL, should be the name of a suitable BFD target. */
+
+ctf_archive_t *
+ctf_fdopen (int fd, const char *filename, const char *target, int *errp)
+{
+ ctf_archive_t *arci;
+ bfd *abfd;
+ int nfd;
+
+ struct stat st;
+ ssize_t nbytes;
+
+ ctf_preamble_t ctfhdr;
+ uint64_t arc_magic;
+
+ memset (&ctfhdr, 0, sizeof (ctfhdr));
+
+ libctf_init_debug();
+
+ if (fstat (fd, &st) == -1)
+ return (ctf_set_open_errno (errp, errno));
+
+ if ((nbytes = ctf_pread (fd, &ctfhdr, sizeof (ctfhdr), 0)) <= 0)
+ return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT));
+
+ /* If we have read enough bytes to form a CTF header and the magic
+ string matches, attempt to interpret the file as raw CTF. */
+
+ if ((size_t) nbytes >= sizeof (ctf_preamble_t) &&
+ ctfhdr.ctp_magic == CTF_MAGIC)
+ {
+ ctf_file_t *fp = NULL;
+ void *data;
+
+ if (ctfhdr.ctp_version > CTF_VERSION)
+ return (ctf_set_open_errno (errp, ECTF_CTFVERS));
+
+ if ((data = ctf_mmap (st.st_size, 0, fd)) == NULL)
+ return (ctf_set_open_errno (errp, errno));
+
+ if ((fp = ctf_simple_open (data, (size_t) st.st_size, NULL, 0, 0,
+ NULL, 0, errp)) == NULL)
+ ctf_munmap (data, (size_t) st.st_size);
+ fp->ctf_data_mmapped = data;
+ fp->ctf_data_mmapped_len = (size_t) st.st_size;
+
+ return ctf_new_archive_internal (0, NULL, fp, NULL, NULL, errp);
+ }
+
+ if ((nbytes = ctf_pread (fd, &arc_magic, sizeof (arc_magic), 0)) <= 0)
+ return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT));
+
+ if ((size_t) nbytes >= sizeof (uint64_t) && arc_magic == CTFA_MAGIC)
+ {
+ struct ctf_archive *arc;
+
+ if ((arc = ctf_arc_open_internal (filename, errp)) == NULL)
+ return NULL; /* errno is set for us. */
+
+ return ctf_new_archive_internal (1, arc, NULL, NULL, NULL, errp);
+ }
+
+ /* Attempt to open the file with BFD. We must dup the fd first, since bfd
+ takes ownership of the passed fd. */
+
+ if ((nfd = dup (fd)) < 0)
+ return (ctf_set_open_errno (errp, errno));
+
+ if ((abfd = bfd_fdopenr (filename, target, nfd)) == NULL)
+ {
+ ctf_dprintf ("Cannot open BFD from %s: %s\n",
+ filename ? filename : "(unknown file)",
+ bfd_errmsg (bfd_get_error()));
+ return (ctf_set_open_errno (errp, ECTF_FMT));
+ }
+
+ if (!bfd_check_format (abfd, bfd_object))
+ {
+ ctf_dprintf ("BFD format problem in %s: %s\n",
+ filename ? filename : "(unknown file)",
+ bfd_errmsg (bfd_get_error()));
+ if (bfd_get_error() == bfd_error_file_ambiguously_recognized)
+ return (ctf_set_open_errno (errp, ECTF_BFD_AMBIGUOUS));
+ else
+ return (ctf_set_open_errno (errp, ECTF_FMT));
+ }
+
+ if ((arci = ctf_bfdopen (abfd, errp)) == NULL)
+ {
+ if (!bfd_close_all_done (abfd))
+ ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error()));
+ return NULL; /* errno is set for us. */
+ }
+ arci->ctfi_bfd_close = ctf_bfdclose;
+ arci->ctfi_abfd = abfd;
+
+ return arci;
+}
+
+/* Open the specified file and return a pointer to a CTF container. The file
+ can be either an ELF file or raw CTF file. This is just a convenient
+ wrapper around ctf_fdopen() for callers. */
+
+ctf_archive_t *
+ctf_open (const char *filename, const char *target, int *errp)
+{
+ ctf_archive_t *arc;
+ int fd;
+
+ if ((fd = open (filename, O_RDONLY)) == -1)
+ {
+ if (errp != NULL)
+ *errp = errno;
+ return NULL;
+ }
+
+ arc = ctf_fdopen (fd, filename, target, errp);
+ (void) close (fd);
+ return arc;
+}
+
+/* Public entry point: open a CTF archive, or CTF file. Returns the archive, or
+ NULL and an error in *err. Despite the fact that this uses CTF archives, it
+ must be in this file to avoid dragging in BFD into non-BFD-using programs. */
+ctf_archive_t *
+ctf_arc_open (const char *filename, int *errp)
+{
+ return ctf_open (filename, NULL, errp);
+}
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