/*
* read_exec
* Read the exec structure; ignore any files that don't look
* exactly right. Return MID.
* return -1 for files that don't look right.
* XXX it's hard to be sure when to ignore files, and when to error
* out.
*/
int
read_exec(FILE *rfp, FILE *wfp, long *symcnt, long *tsymlen)
{
union {
struct exec exec;
Elf32_Ehdr elf32;
Elf64_Ehdr elf64;
} eh;
struct nlist nl;
off_t r_off, w_off;
char *strtab = NULL;
long strsize, nsyms;
int i;
/* Get current offsets for original and tmp files. */
r_off = ftello(rfp);
w_off = ftello(wfp);
/* Read in exec structure. */
if (fread(&eh, sizeof(eh), 1, rfp) != 1)
err(1, "fread: %s", archive);
if (!elf32_chk_header(&eh.elf32)) {
Elf32_Sym sbuf;
char *shstr;
Elf32_Shdr *shdr;
size_t stabsize;
elf32_fix_header(&eh.elf32);
if (eh.elf32.e_ehsize < sizeof eh.elf32) {
warnx("%s: ELF header is too short", archive);
goto bad;
}
if (!(shdr = elf32_load_shdrs(archive, rfp, r_off, &eh.elf32)))
goto bad;
elf32_fix_shdrs(&eh.elf32, shdr);
if (!(shstr = elf32_shstrload(archive, rfp, r_off, &eh.elf32,
shdr))) {
free(shdr);
goto bad;
}
if (!(strtab = elf32_strload(archive, rfp, r_off, &eh.elf32,
shdr, shstr, ELF_STRTAB, &stabsize))) {
free(shstr);
free(shdr);
goto bad;
}
/* find the symtab section */
for (i = 0; i < eh.elf32.e_shnum; i++)
if (!strcmp(shstr + shdr[i].sh_name, ELF_SYMTAB)) {
nsyms = shdr[i].sh_size / sizeof(Elf32_Sym);
break;
}
if (i == eh.elf32.e_shnum) {
free(shstr);
free(shdr);
goto bad;
}
if (fseeko(rfp, r_off + shdr[i].sh_offset, SEEK_SET))
err(1, "fseeko: %s", archive);
for (i = 0; i < nsyms; i++) {
if (fread(&sbuf, sizeof(sbuf), 1, rfp) != 1)
err(1, "fread: %s", archive);
elf32_fix_sym(&eh.elf32, &sbuf);
if (!sbuf.st_name || sbuf.st_name > stabsize)
continue;
if (elf32_2nlist(&sbuf, &eh.elf32, shdr, shstr, &nl))
continue;
addsym(&nl, strtab, r_off - r_fuzz -
sizeof(struct ar_hdr), symcnt, tsymlen, archive);
}
free(strtab);
free(shstr);
free(shdr);
(void)fseeko(rfp, r_off, SEEK_SET);
return MID_ELFFL | eh.elf32.e_machine;
} else if (!elf64_chk_header(&eh.elf64)) {
Elf64_Sym sbuf;
char *shstr;
Elf64_Shdr *shdr;
size_t stabsize;
elf64_fix_header(&eh.elf64);
if (eh.elf64.e_ehsize < sizeof eh.elf64) {
warnx("%s: ELF header is too short", archive);
goto bad;
}
if (!(shdr = elf64_load_shdrs(archive, rfp, r_off, &eh.elf64)))
goto bad;
elf64_fix_shdrs(&eh.elf64, shdr);
if (!(shstr = elf64_shstrload(archive, rfp, r_off, &eh.elf64,
shdr))) {
free(shdr);
goto bad;
}
if (!(strtab = elf64_strload(archive, rfp, r_off, &eh.elf64,
shdr, shstr, ELF_STRTAB, &stabsize))) {
free(shstr);
free(shdr);
goto bad;
}
/* find the symtab section */
for (i = 0; i < eh.elf64.e_shnum; i++)
if (!strcmp(shstr + shdr[i].sh_name, ELF_SYMTAB)) {
nsyms = shdr[i].sh_size / sizeof(Elf64_Sym);
break;
}
if (i == eh.elf64.e_shnum) {
free(shstr);
free(shdr);
goto bad;
}
if (fseeko(rfp, r_off + shdr[i].sh_offset, SEEK_SET))
err(1, "fseeko: %s", archive);
for (i = 0; i < nsyms; i++) {
if (fread(&sbuf, sizeof(sbuf), 1, rfp) != 1)
err(1, "fread: %s", archive);
elf64_fix_sym(&eh.elf64, &sbuf);
if (!sbuf.st_name || sbuf.st_name > stabsize)
continue;
if (elf64_2nlist(&sbuf, &eh.elf64, shdr, shstr, &nl))
continue;
addsym(&nl, strtab, r_off - r_fuzz -
sizeof(struct ar_hdr), symcnt, tsymlen, archive);
}
free(strtab);
free(shstr);
free(shdr);
(void)fseeko(rfp, r_off, SEEK_SET);
return MID_ELFFL | eh.elf64.e_machine;
} else if (BAD_OBJECT(eh.exec) || eh.exec.a_syms == 0)
goto bad;
fix_header_order(&eh.exec);
/* Seek to string table. */
if (fseeko(rfp, N_STROFF(eh.exec) + r_off, SEEK_SET) == -1) {
if (errno == EINVAL)
goto bad;
else
err(1, "lseek: %s", archive);
}
/* Read in size of the string table. */
if (fread((char *)&strsize, sizeof(strsize), 1, rfp) != 1)
err(1, "fread: %s", archive);
strsize = fix_32_order(strsize, N_GETMID(eh.exec));
/* Read in the string table. */
strsize -= sizeof(strsize);
strtab = malloc(strsize);
if (!strtab)
err(1, "malloc: %s", archive);
if (fread(strtab, strsize, 1, rfp) != 1)
err(1, "fread: %s", archive);
/* Seek to symbol table. */
if (fseek(rfp, N_SYMOFF(eh.exec) + r_off, SEEK_SET) == (off_t)-1)
err(1, "fseeko: %s", archive);
/* For each symbol read the nlist entry and save it as necessary. */
nsyms = eh.exec.a_syms / sizeof(struct nlist);
while (nsyms--) {
if (!fread((char *)&nl, sizeof(struct nlist), 1, rfp)) {
if (feof(rfp))
badfmt();
err(1, "fread: %s", archive);
}
fix_nlist_order(&nl, N_GETMID(eh.exec));
addsym(&nl, strtab - sizeof(long), r_off - r_fuzz -
sizeof(struct ar_hdr), symcnt, tsymlen, archive);
}
bad:
free(strtab);
(void)fseeko(rfp, r_off, SEEK_SET);
return N_GETMID(eh.exec);
}
/*
* rexec
* Read the exec structure; ignore any files that don't look
* exactly right. Return MID.
* return -1 for files that don't look right.
* XXX it's hard to be sure when to ignore files, and when to error
* out.
*/
static int
rexec(int rfd, int wfd)
{
RLIB *rp;
long nsyms;
int nr, symlen;
char *strtab = 0;
char *sym;
struct exec ebuf;
struct nlist nl;
off_t r_off, w_off;
long strsize;
int result = -1;
/* Get current offsets for original and tmp files. */
r_off = lseek(rfd, (off_t)0, SEEK_CUR);
w_off = lseek(wfd, (off_t)0, SEEK_CUR);
/* Read in exec structure. */
nr = read(rfd, (char *)&ebuf, sizeof(struct exec));
if (nr != sizeof(struct exec))
goto bad;
/* Check magic number and symbol count. */
if (BAD_OBJECT(ebuf) || ebuf.a_syms == 0)
goto bad;
fix_header_order(&ebuf);
/* Seek to string table. */
if (lseek(rfd, N_STROFF(ebuf) + r_off, SEEK_SET) == (off_t)-1) {
if (errno == EINVAL)
goto bad;
else
error(archive);
}
/* Read in size of the string table. */
nr = read(rfd, (char *)&strsize, sizeof(strsize));
if (nr != sizeof(strsize))
goto bad;
strsize = fix_32_order(strsize, N_GETMID(ebuf));
/* Read in the string table. */
strsize -= sizeof(strsize);
strtab = (char *)emalloc(strsize);
nr = read(rfd, strtab, strsize);
if (nr != strsize)
goto bad;
/* Seek to symbol table. */
if (fseek(fp, N_SYMOFF(ebuf) + r_off, SEEK_SET) == (off_t)-1)
goto bad;
result = N_GETMID(ebuf);
/* For each symbol read the nlist entry and save it as necessary. */
nsyms = ebuf.a_syms / sizeof(struct nlist);
while (nsyms--) {
if (!fread((char *)&nl, sizeof(struct nlist), 1, fp)) {
if (feof(fp))
badfmt();
error(archive);
}
fix_nlist_order(&nl, N_GETMID(ebuf));
/* Ignore if no name or local. */
if (!nl.n_un.n_strx || !(nl.n_type & N_EXT))
continue;
/*
* If the symbol is an undefined external and the n_value
* field is non-zero, keep it.
*/
if ((nl.n_type & N_TYPE) == N_UNDF && !nl.n_value)
continue;
/* First four bytes are the table size. */
sym = strtab + nl.n_un.n_strx - sizeof(long);
symlen = strlen(sym) + 1;
rp = (RLIB *)emalloc(sizeof(RLIB));
rp->sym = (char *)emalloc(symlen);
bcopy(sym, rp->sym, symlen);
rp->symlen = symlen;
rp->pos = w_off;
/* Build in forward order for "ar -m" command. */
*pnext = rp;
pnext = &rp->next;
++symcnt;
tsymlen += symlen;
}
bad: if (nr < 0)
error(archive);
free(strtab);
(void)lseek(rfd, (off_t)r_off, SEEK_SET);
return result;
}
