/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright (c) 2019, Joyent, Inc.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <libctf_impl.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <dlfcn.h>
#include <gelf.h>
#include <zlib.h>
#include <sys/debug.h>

#ifdef _LP64
static const char *_libctf_zlib = "/usr/lib/64/libz.so.1";
#else
static const char *_libctf_zlib = "/usr/lib/libz.so.1";
#endif

static struct {
        int (*z_uncompress)(uchar_t *, ulong_t *, const uchar_t *, ulong_t);
        int (*z_initcomp)(z_stream *, int, const char *, int);
        int (*z_compress)(z_stream *, int);
        int (*z_finicomp)(z_stream *);
        const char *(*z_error)(int);
        void *z_dlp;
} zlib;

static size_t _PAGESIZE;
static size_t _PAGEMASK;

static uint64_t ctf_phase = 0;

#define CTF_COMPRESS_CHUNK      (64*1024)

typedef struct ctf_zdata {
        void            *czd_buf;
        void            *czd_next;
        ctf_file_t      *czd_ctfp;
        size_t          czd_allocsz;
        z_stream        czd_zstr;
} ctf_zdata_t;

#pragma init(_libctf_init)
void
_libctf_init(void)
{
        const char *p = getenv("LIBCTF_DECOMPRESSOR");

        if (p != NULL)
                _libctf_zlib = p; /* use alternate decompression library */

        _libctf_debug = getenv("LIBCTF_DEBUG") != NULL;

        _PAGESIZE = getpagesize();
        _PAGEMASK = ~(_PAGESIZE - 1);
}

/*
 * Attempt to dlopen the decompression library and locate the symbols of
 * interest that we will need to call.  This information in cached so
 * that multiple calls to ctf_bufopen() do not need to reopen the library.
 */
void *
ctf_zopen(int *errp)
{
        ctf_dprintf("decompressing CTF data using %s\n", _libctf_zlib);

        if (zlib.z_dlp != NULL)
                return (zlib.z_dlp); /* library is already loaded */

        if (access(_libctf_zlib, R_OK) == -1)
                return (ctf_set_open_errno(errp, ECTF_ZMISSING));

        if ((zlib.z_dlp = dlopen(_libctf_zlib, RTLD_LAZY | RTLD_LOCAL)) == NULL)
                return (ctf_set_open_errno(errp, ECTF_ZINIT));

        zlib.z_uncompress = (int (*)()) dlsym(zlib.z_dlp, "uncompress");
        zlib.z_initcomp = (int (*)()) dlsym(zlib.z_dlp, "deflateInit_");
        zlib.z_compress = (int (*)()) dlsym(zlib.z_dlp, "deflate");
        zlib.z_finicomp = (int (*)()) dlsym(zlib.z_dlp, "deflateEnd");
        zlib.z_error = (const char *(*)()) dlsym(zlib.z_dlp, "zError");

        if (zlib.z_uncompress == NULL || zlib.z_error == NULL ||
            zlib.z_initcomp == NULL|| zlib.z_compress == NULL ||
            zlib.z_finicomp == NULL) {
                (void) dlclose(zlib.z_dlp);
                bzero(&zlib, sizeof (zlib));
                return (ctf_set_open_errno(errp, ECTF_ZINIT));
        }

        return (zlib.z_dlp);
}

/*
 * The ctf_bufopen() routine calls these subroutines, defined by <sys/zmod.h>,
 * which we then patch through to the functions in the decompression library.
 */
int
z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
{
        return (zlib.z_uncompress(dst, (ulong_t *)dstlen, src, srclen));
}

const char *
z_strerror(int err)
{
        return (zlib.z_error(err));
}

static int
ctf_zdata_init(ctf_zdata_t *czd, ctf_file_t *fp)
{
        ctf_header_t *cthp;

        bzero(czd, sizeof (ctf_zdata_t));

        czd->czd_allocsz = fp->ctf_size;
        czd->czd_buf = ctf_data_alloc(czd->czd_allocsz);
        if (czd->czd_buf == MAP_FAILED)
                return (ctf_set_errno(fp, ENOMEM));

        bcopy(fp->ctf_base, czd->czd_buf, sizeof (ctf_header_t));
        czd->czd_ctfp = fp;
        cthp = czd->czd_buf;
        cthp->cth_flags |= CTF_F_COMPRESS;
        czd->czd_next = (void *)((uintptr_t)czd->czd_buf +
            sizeof (ctf_header_t));

        if (zlib.z_initcomp(&czd->czd_zstr, Z_BEST_COMPRESSION,
            ZLIB_VERSION, sizeof (z_stream)) != Z_OK)
                return (ctf_set_errno(fp, ECTF_ZLIB));

        return (0);
}

static int
ctf_zdata_grow(ctf_zdata_t *czd)
{
        size_t off;
        size_t newsz;
        void *ndata;

        off = (uintptr_t)czd->czd_next - (uintptr_t)czd->czd_buf;
        newsz = czd->czd_allocsz + CTF_COMPRESS_CHUNK;
        ndata = ctf_data_alloc(newsz);
        if (ndata == MAP_FAILED) {
                return (ctf_set_errno(czd->czd_ctfp, ENOMEM));
        }

        bcopy(czd->czd_buf, ndata, off);
        ctf_data_free(czd->czd_buf, czd->czd_allocsz);
        czd->czd_allocsz = newsz;
        czd->czd_buf = ndata;
        czd->czd_next = (void *)((uintptr_t)ndata + off);

        czd->czd_zstr.next_out = (Bytef *)czd->czd_next;
        czd->czd_zstr.avail_out = CTF_COMPRESS_CHUNK;
        return (0);
}

static int
ctf_zdata_compress_buffer(ctf_zdata_t *czd, const void *buf, size_t bufsize)
{
        int err;

        czd->czd_zstr.next_out = czd->czd_next;
        czd->czd_zstr.avail_out = czd->czd_allocsz -
            ((uintptr_t)czd->czd_next - (uintptr_t)czd->czd_buf);
        czd->czd_zstr.next_in = (Bytef *)buf;
        czd->czd_zstr.avail_in = bufsize;

        while (czd->czd_zstr.avail_in != 0) {
                if (czd->czd_zstr.avail_out == 0) {
                        czd->czd_next = czd->czd_zstr.next_out;
                        if ((err = ctf_zdata_grow(czd)) != 0) {
                                return (err);
                        }
                }

                if ((err = zlib.z_compress(&czd->czd_zstr, Z_NO_FLUSH)) != Z_OK)
                        return (ctf_set_errno(czd->czd_ctfp, ECTF_ZLIB));
        }
        czd->czd_next = czd->czd_zstr.next_out;

        return (0);
}

static int
ctf_zdata_flush(ctf_zdata_t *czd, boolean_t finish)
{
        int err;
        int flag = finish == B_TRUE ? Z_FINISH : Z_FULL_FLUSH;
        int bret = finish == B_TRUE ? Z_STREAM_END : Z_BUF_ERROR;

        for (;;) {
                if (czd->czd_zstr.avail_out == 0) {
                        czd->czd_next = czd->czd_zstr.next_out;
                        if ((err = ctf_zdata_grow(czd)) != 0) {
                                return (err);
                        }
                }

                err = zlib.z_compress(&czd->czd_zstr, flag);
                if (err == bret) {
                        break;
                }
                if (err != Z_OK)
                        return (ctf_set_errno(czd->czd_ctfp, ECTF_ZLIB));

        }

        czd->czd_next = czd->czd_zstr.next_out;

        return (0);
}

static int
ctf_zdata_end(ctf_zdata_t *czd)
{
        int ret;

        if ((ret = ctf_zdata_flush(czd, B_TRUE)) != 0)
                return (ret);

        if ((ret = zlib.z_finicomp(&czd->czd_zstr)) != 0)
                return (ctf_set_errno(czd->czd_ctfp, ECTF_ZLIB));

        return (0);
}

static void
ctf_zdata_cleanup(ctf_zdata_t *czd)
{
        ctf_data_free(czd->czd_buf, czd->czd_allocsz);
        (void) zlib.z_finicomp(&czd->czd_zstr);
}

/*
 * Compress our CTF data and return both the size of the compressed data and the
 * size of the allocation. These may be different due to the nature of
 * compression.
 *
 * In addition, we flush the compression between our two phases such that we
 * maintain a different dictionary between the CTF data and the string section.
 */
int
ctf_compress(ctf_file_t *fp, void **buf, size_t *allocsz, size_t *elfsize)
{
        int err;
        ctf_zdata_t czd;
        ctf_header_t *cthp = (ctf_header_t *)fp->ctf_base;

        if ((err = ctf_zdata_init(&czd, fp)) != 0)
                return (err);

        if ((err = ctf_zdata_compress_buffer(&czd, fp->ctf_buf,
            cthp->cth_stroff)) != 0) {
                ctf_zdata_cleanup(&czd);
                return (err);
        }

        if ((err = ctf_zdata_flush(&czd, B_FALSE)) != 0) {
                ctf_zdata_cleanup(&czd);
                return (err);
        }

        if ((err = ctf_zdata_compress_buffer(&czd,
            fp->ctf_buf + cthp->cth_stroff, cthp->cth_strlen)) != 0) {
                ctf_zdata_cleanup(&czd);
                return (err);
        }

        if ((err = ctf_zdata_end(&czd)) != 0) {
                ctf_zdata_cleanup(&czd);
                return (err);
        }

        *buf = czd.czd_buf;
        *allocsz = czd.czd_allocsz;
        *elfsize = (uintptr_t)czd.czd_next - (uintptr_t)czd.czd_buf;

        return (0);
}

int
z_compress(void *dst, size_t *dstlen, const void *src, size_t srclen)
{
        z_stream zs;
        int err;

        bzero(&zs, sizeof (z_stream));
        zs.next_in = (uchar_t *)src;
        zs.avail_in = srclen;
        zs.next_out = dst;
        zs.avail_out = *dstlen;

        if ((err = zlib.z_initcomp(&zs, Z_BEST_COMPRESSION, ZLIB_VERSION,
            sizeof (z_stream))) != Z_OK)
                return (err);

        if ((err = zlib.z_compress(&zs, Z_FINISH)) != Z_STREAM_END) {
                (void) zlib.z_finicomp(&zs);
                return (err == Z_OK ? Z_BUF_ERROR : err);
        }

        *dstlen = zs.total_out;
        return (zlib.z_finicomp(&zs));
}

/*
 * Convert a 32-bit ELF file header into GElf.
 */
static void
ehdr_to_gelf(const Elf32_Ehdr *src, GElf_Ehdr *dst)
{
        bcopy(src->e_ident, dst->e_ident, EI_NIDENT);
        dst->e_type = src->e_type;
        dst->e_machine = src->e_machine;
        dst->e_version = src->e_version;
        dst->e_entry = (Elf64_Addr)src->e_entry;
        dst->e_phoff = (Elf64_Off)src->e_phoff;
        dst->e_shoff = (Elf64_Off)src->e_shoff;
        dst->e_flags = src->e_flags;
        dst->e_ehsize = src->e_ehsize;
        dst->e_phentsize = src->e_phentsize;
        dst->e_phnum = src->e_phnum;
        dst->e_shentsize = src->e_shentsize;
        dst->e_shnum = src->e_shnum;
        dst->e_shstrndx = src->e_shstrndx;
}

/*
 * Convert a 32-bit ELF section header into GElf.
 */
static void
shdr_to_gelf(const Elf32_Shdr *src, GElf_Shdr *dst)
{
        dst->sh_name = src->sh_name;
        dst->sh_type = src->sh_type;
        dst->sh_flags = src->sh_flags;
        dst->sh_addr = src->sh_addr;
        dst->sh_offset = src->sh_offset;
        dst->sh_size = src->sh_size;
        dst->sh_link = src->sh_link;
        dst->sh_info = src->sh_info;
        dst->sh_addralign = src->sh_addralign;
        dst->sh_entsize = src->sh_entsize;
}

/*
 * In order to mmap a section from the ELF file, we must round down sh_offset
 * to the previous page boundary, and mmap the surrounding page.  We store
 * the pointer to the start of the actual section data back into sp->cts_data.
 */
const void *
ctf_sect_mmap(ctf_sect_t *sp, int fd)
{
        size_t pageoff = sp->cts_offset & ~_PAGEMASK;

        caddr_t base = mmap64(NULL, sp->cts_size + pageoff, PROT_READ,
            MAP_PRIVATE, fd, sp->cts_offset & _PAGEMASK);

        if (base != MAP_FAILED)
                sp->cts_data = base + pageoff;

        return (base);
}

/*
 * Since sp->cts_data has the adjusted offset, we have to again round down
 * to get the actual mmap address and round up to get the size.
 */
void
ctf_sect_munmap(const ctf_sect_t *sp)
{
        uintptr_t addr = (uintptr_t)sp->cts_data;
        uintptr_t pageoff = addr & ~_PAGEMASK;

        (void) munmap((void *)(addr - pageoff), sp->cts_size + pageoff);
}

/*
 * Open the specified file descriptor and return a pointer to a CTF container.
 * The file can be either an ELF file or raw CTF file.  The caller is
 * responsible for closing the file descriptor when it is no longer needed.
 */
ctf_file_t *
ctf_fdcreate_int(int fd, int *errp, ctf_sect_t *ctfp)
{
        ctf_sect_t ctfsect, symsect, strsect;
        ctf_file_t *fp = NULL;
        size_t shstrndx, shnum;

        struct stat64 st;
        ssize_t nbytes;

        union {
                ctf_preamble_t ctf;
                Elf32_Ehdr e32;
                GElf_Ehdr e64;
        } hdr;

        bzero(&ctfsect, sizeof (ctf_sect_t));
        bzero(&symsect, sizeof (ctf_sect_t));
        bzero(&strsect, sizeof (ctf_sect_t));
        bzero(&hdr.ctf, sizeof (hdr));

        if (fstat64(fd, &st) == -1)
                return (ctf_set_open_errno(errp, errno));

        if ((nbytes = pread64(fd, &hdr.ctf, sizeof (hdr), 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 (nbytes >= sizeof (ctf_preamble_t) &&
            hdr.ctf.ctp_magic == CTF_MAGIC) {
                if (ctfp != NULL)
                        return (ctf_set_open_errno(errp, EINVAL));

                if (hdr.ctf.ctp_version > CTF_VERSION)
                        return (ctf_set_open_errno(errp, ECTF_CTFVERS));

                ctfsect.cts_data = mmap64(NULL, st.st_size, PROT_READ,
                    MAP_PRIVATE, fd, 0);

                if (ctfsect.cts_data == MAP_FAILED)
                        return (ctf_set_open_errno(errp, errno));

                ctfsect.cts_name = _CTF_SECTION;
                ctfsect.cts_type = SHT_PROGBITS;
                ctfsect.cts_flags = SHF_ALLOC;
                ctfsect.cts_size = (size_t)st.st_size;
                ctfsect.cts_entsize = 1;
                ctfsect.cts_offset = 0;

                if ((fp = ctf_bufopen(&ctfsect, NULL, NULL, errp)) == NULL)
                        ctf_sect_munmap(&ctfsect);

                return (fp);
        }

        /*
         * If we have read enough bytes to form an ELF header and the magic
         * string matches, attempt to interpret the file as an ELF file.  We
         * do our own largefile ELF processing, and convert everything to
         * GElf structures so that clients can operate on any data model.
         */
        if (nbytes >= sizeof (Elf32_Ehdr) &&
            bcmp(&hdr.e32.e_ident[EI_MAG0], ELFMAG, SELFMAG) == 0) {
#ifdef  _BIG_ENDIAN
                uchar_t order = ELFDATA2MSB;
#else
                uchar_t order = ELFDATA2LSB;
#endif
                GElf_Shdr *sp;

                void *strs_map;
                size_t strs_mapsz, i;
                const char *strs;

                if (hdr.e32.e_ident[EI_DATA] != order)
                        return (ctf_set_open_errno(errp, ECTF_ENDIAN));
                if (hdr.e32.e_version != EV_CURRENT)
                        return (ctf_set_open_errno(errp, ECTF_ELFVERS));

                if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS64) {
                        if (nbytes < sizeof (GElf_Ehdr))
                                return (ctf_set_open_errno(errp, ECTF_FMT));
                } else {
                        Elf32_Ehdr e32 = hdr.e32;
                        ehdr_to_gelf(&e32, &hdr.e64);
                }

                shnum = hdr.e64.e_shnum;
                shstrndx = hdr.e64.e_shstrndx;

                /* Extended ELF sections */
                if ((shstrndx == SHN_XINDEX) || (shnum == 0)) {
                        if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS32) {
                                Elf32_Shdr x32;

                                if (pread64(fd, &x32, sizeof (x32),
                                    hdr.e64.e_shoff) != sizeof (x32))
                                        return (ctf_set_open_errno(errp,
                                            errno));

                                shnum = x32.sh_size;
                                shstrndx = x32.sh_link;
                        } else {
                                Elf64_Shdr x64;

                                if (pread64(fd, &x64, sizeof (x64),
                                    hdr.e64.e_shoff) != sizeof (x64))
                                        return (ctf_set_open_errno(errp,
                                            errno));

                                shnum = x64.sh_size;
                                shstrndx = x64.sh_link;
                        }
                }

                if (shstrndx >= shnum)
                        return (ctf_set_open_errno(errp, ECTF_CORRUPT));

                nbytes = sizeof (GElf_Shdr) * shnum;

                if ((sp = malloc(nbytes)) == NULL)
                        return (ctf_set_open_errno(errp, errno));

                /*
                 * Read in and convert to GElf the array of Shdr structures
                 * from e_shoff so we can locate sections of interest.
                 */
                if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS32) {
                        Elf32_Shdr *sp32;

                        nbytes = sizeof (Elf32_Shdr) * shnum;

                        if ((sp32 = malloc(nbytes)) == NULL || pread64(fd,
                            sp32, nbytes, hdr.e64.e_shoff) != nbytes) {
                                free(sp);
                                return (ctf_set_open_errno(errp, errno));
                        }

                        for (i = 0; i < shnum; i++)
                                shdr_to_gelf(&sp32[i], &sp[i]);

                        free(sp32);

                } else if (pread64(fd, sp, nbytes, hdr.e64.e_shoff) != nbytes) {
                        free(sp);
                        return (ctf_set_open_errno(errp, errno));
                }

                /*
                 * Now mmap the section header strings section so that we can
                 * perform string comparison on the section names.
                 */
                strs_mapsz = sp[shstrndx].sh_size +
                    (sp[shstrndx].sh_offset & ~_PAGEMASK);

                strs_map = mmap64(NULL, strs_mapsz, PROT_READ, MAP_PRIVATE,
                    fd, sp[shstrndx].sh_offset & _PAGEMASK);

                strs = (const char *)strs_map +
                    (sp[shstrndx].sh_offset & ~_PAGEMASK);

                if (strs_map == MAP_FAILED) {
                        free(sp);
                        return (ctf_set_open_errno(errp, ECTF_MMAP));
                }

                /*
                 * Iterate over the section header array looking for the CTF
                 * section and symbol table.  The strtab is linked to symtab.
                 */
                for (i = 0; i < shnum; i++) {
                        const GElf_Shdr *shp = &sp[i];
                        const GElf_Shdr *lhp = &sp[shp->sh_link];

                        if (shp->sh_link >= shnum)
                                continue; /* corrupt sh_link field */

                        if (shp->sh_name >= sp[shstrndx].sh_size ||
                            lhp->sh_name >= sp[shstrndx].sh_size)
                                continue; /* corrupt sh_name field */

                        if (shp->sh_type == SHT_PROGBITS &&
                            strcmp(strs + shp->sh_name, _CTF_SECTION) == 0 &&
                            ctfp == NULL) {
                                ctfsect.cts_name = strs + shp->sh_name;
                                ctfsect.cts_type = shp->sh_type;
                                ctfsect.cts_flags = shp->sh_flags;
                                ctfsect.cts_size = shp->sh_size;
                                ctfsect.cts_entsize = shp->sh_entsize;
                                ctfsect.cts_offset = (off64_t)shp->sh_offset;

                        } else if (shp->sh_type == SHT_SYMTAB) {
                                symsect.cts_name = strs + shp->sh_name;
                                symsect.cts_type = shp->sh_type;
                                symsect.cts_flags = shp->sh_flags;
                                symsect.cts_size = shp->sh_size;
                                symsect.cts_entsize = shp->sh_entsize;
                                symsect.cts_offset = (off64_t)shp->sh_offset;

                                strsect.cts_name = strs + lhp->sh_name;
                                strsect.cts_type = lhp->sh_type;
                                strsect.cts_flags = lhp->sh_flags;
                                strsect.cts_size = lhp->sh_size;
                                strsect.cts_entsize = lhp->sh_entsize;
                                strsect.cts_offset = (off64_t)lhp->sh_offset;
                        }
                }

                free(sp); /* free section header array */

                if (ctfp == NULL) {
                        if (ctfsect.cts_type == SHT_NULL && ctfp == NULL) {
                                (void) munmap(strs_map, strs_mapsz);
                                return (ctf_set_open_errno(errp,
                                    ECTF_NOCTFDATA));
                        }

                        /*
                         * Now mmap the CTF data, symtab, and strtab sections
                         * and call ctf_bufopen() to do the rest of the work.
                         */
                        if (ctf_sect_mmap(&ctfsect, fd) == MAP_FAILED) {
                                (void) munmap(strs_map, strs_mapsz);
                                return (ctf_set_open_errno(errp, ECTF_MMAP));
                        }
                        ctfp = &ctfsect;
                }

                if (symsect.cts_type != SHT_NULL &&
                    strsect.cts_type != SHT_NULL) {
                        if (ctf_sect_mmap(&symsect, fd) == MAP_FAILED ||
                            ctf_sect_mmap(&strsect, fd) == MAP_FAILED) {
                                (void) ctf_set_open_errno(errp, ECTF_MMAP);
                                goto bad; /* unmap all and abort */
                        }
                        fp = ctf_bufopen(ctfp, &symsect, &strsect, errp);
                } else
                        fp = ctf_bufopen(ctfp, NULL, NULL, errp);
bad:
                if (fp == NULL) {
                        if (ctfp == NULL)
                                ctf_sect_munmap(&ctfsect);
                        ctf_sect_munmap(&symsect);
                        ctf_sect_munmap(&strsect);
                } else
                        fp->ctf_flags |= LCTF_MMAP;

                (void) munmap(strs_map, strs_mapsz);
                return (fp);
        }

        return (ctf_set_open_errno(errp, ECTF_FMT));
}

ctf_file_t *
ctf_fdopen(int fd, int *errp)
{
        return (ctf_fdcreate_int(fd, errp, NULL));
}

/*
 * 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_file_t *
ctf_open(const char *filename, int *errp)
{
        ctf_file_t *fp;
        int fd;

        if ((fd = open64(filename, O_RDONLY)) == -1) {
                if (errp != NULL)
                        *errp = errno;
                return (NULL);
        }

        fp = ctf_fdopen(fd, errp);
        (void) close(fd);
        return (fp);
}

/*
 * Write the uncompressed CTF data stream to the specified file descriptor.
 * This is useful for saving the results of dynamic CTF containers.
 */
int
ctf_write(ctf_file_t *fp, int fd)
{
        const uchar_t *buf = fp->ctf_base;
        ssize_t resid = fp->ctf_size;
        ssize_t len;

        while (resid != 0) {
                if ((len = write(fd, buf, resid)) <= 0)
                        return (ctf_set_errno(fp, errno));
                resid -= len;
                buf += len;
        }

        return (0);
}

/*
 * Set the CTF library client version to the specified version.  If version is
 * zero, we just return the default library version number.
 */
int
ctf_version(int version)
{
        if (version < 0) {
                errno = EINVAL;
                return (-1);
        }

        if (version > 0) {
                if (version > CTF_VERSION) {
                        errno = ENOTSUP;
                        return (-1);
                }
                ctf_dprintf("ctf_version: client using version %d\n", version);
                _libctf_version = version;
        }

        return (_libctf_version);
}

/*
 * A utility function for folks debugging CTF conversion and merging.
 */
void
ctf_phase_dump(ctf_file_t *fp, const char *phase, const char *name)
{
        int fd;
        static char *base;
        char path[MAXPATHLEN];

        if (base == NULL && (base = getenv("LIBCTF_WRITE_PHASES")) == NULL)
                return;

        if (name == NULL)
                name = "libctf";

        (void) snprintf(path, sizeof (path), "%s/%s.%s.%d.ctf", base, name,
            phase != NULL ? phase : "",
            ctf_phase);
        if ((fd = open(path, O_CREAT | O_TRUNC | O_RDWR, 0777)) < 0)
                return;
        (void) ctf_write(fp, fd);
        (void) close(fd);
}

void
ctf_phase_bump(void)
{
        ctf_phase++;
}

int
ctf_symtab_iter(ctf_file_t *fp, ctf_symtab_f func, void *arg)
{
        ulong_t i;
        uintptr_t symbase;
        uintptr_t strbase;
        const char *file = NULL;
        boolean_t primary = B_TRUE;

        if (fp->ctf_symtab.cts_data == NULL ||
            fp->ctf_strtab.cts_data == NULL) {
                return (ECTF_NOSYMTAB);
        }

        symbase = (uintptr_t)fp->ctf_symtab.cts_data;
        strbase = (uintptr_t)fp->ctf_strtab.cts_data;

        for (i = 0; i < fp->ctf_nsyms; i++) {
                const char *name;
                int ret;
                uint_t type;
                Elf64_Sym sym;

                /*
                 * The CTF library has historically tried to handle large file
                 * offsets itself so that way clients can be unaware of such
                 * isseus. Therefore, we translate everything to a 64-bit ELF
                 * symbol, this is done to make it so that the rest of the
                 * library doesn't have to know about these differences. For
                 * more information see, lib/libctf/common/ctf_lib.c.
                 */
                if (fp->ctf_symtab.cts_entsize == sizeof (Elf32_Sym)) {
                        const Elf32_Sym *symp = (Elf32_Sym *)symbase + i;
                        uint_t bind, itype;

                        sym.st_name = symp->st_name;
                        sym.st_value = symp->st_value;
                        sym.st_size = symp->st_size;
                        bind = ELF32_ST_BIND(symp->st_info);
                        itype = ELF32_ST_TYPE(symp->st_info);
                        sym.st_info = ELF64_ST_INFO(bind, itype);
                        sym.st_other = symp->st_other;
                        sym.st_shndx = symp->st_shndx;
                } else {
                        const Elf64_Sym *symp = (Elf64_Sym *)symbase + i;

                        sym = *symp;
                }

                type = ELF64_ST_TYPE(sym.st_info);
                name = (const char *)(strbase + sym.st_name);

                /*
                 * Check first if we have an STT_FILE entry. This is used to
                 * distinguish between various local symbols when merging.
                 */
                if (type == STT_FILE) {
                        if (file != NULL) {
                                primary = B_FALSE;
                        }
                        file = name;
                        continue;
                }

                /*
                 * Check if this is a symbol that we care about.
                 */
                if (!ctf_sym_valid(strbase, type, sym.st_shndx, sym.st_value,
                    sym.st_name)) {
                        continue;
                }

                if ((ret = func(&sym, i, file, name, primary, arg)) != 0) {
                        return (ret);
                }
        }

        return (0);
}