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-rw-r--r--dln.c1088
1 files changed, 1088 insertions, 0 deletions
diff --git a/dln.c b/dln.c
new file mode 100644
index 0000000..766297e
--- /dev/null
+++ b/dln.c
@@ -0,0 +1,1088 @@
+/************************************************
+
+ dln.c -
+
+ $Author: matz $
+ $Date: 1994/06/17 14:23:49 $
+ created at: Tue Jan 18 17:05:06 JST 1994
+
+ Copyright (C) 1994 Yukihiro Matsumoto
+
+************************************************/
+
+#include <stdio.h>
+#include <sys/param.h>
+#include <sys/file.h>
+#include "defines.h"
+#include "dln.h"
+#include <sys/types.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+char *strdup();
+
+extern int errno;
+int dln_errno;
+
+static int dln_init_p = 0;
+
+#include <sys/stat.h>
+
+static char fbuf[MAXPATHLEN];
+static char *dln_find_1();
+char *getenv();
+char *index();
+int strcmp();
+
+char *
+dln_find_exe(fname, path)
+ char *fname;
+ char *path;
+{
+ if (!path) path = getenv("PATH");
+ if (!path) path = "/usr/local/bin:/usr/ucb:/usr/bin:/bin:.";
+ return dln_find_1(fname, path, 1);
+}
+
+char *
+dln_find_file(fname, path)
+ char *fname;
+ char *path;
+{
+ if (!path) path = ".";
+ return dln_find_1(fname, path, 0);
+}
+
+static char *
+dln_find_1(fname, path, exe_flag)
+ char *fname;
+ char *path;
+ int exe_flag; /* non 0 if looking for executable. */
+{
+ register char *dp;
+ register char *ep;
+ register char *bp;
+ struct stat st;
+
+ if (fname[0] == '/') return fname;
+
+ for (dp = path;; dp = ++ep)
+ {
+ register int l;
+ int i;
+ int fspace;
+
+ /* extract a component */
+ ep = index(dp, ':');
+ if (ep == NULL)
+ ep = dp+strlen(dp);
+
+ /* find the length of that component */
+ l = ep - dp;
+ bp = fbuf;
+ fspace = sizeof fbuf - 2;
+ if (l > 0)
+ {
+ /*
+ ** If the length of the component is zero length,
+ ** start from the current directory. If the
+ ** component begins with "~", start from the
+ ** user's $HOME environment variable. Otherwise
+ ** take the path literally.
+ */
+
+ if (*dp == '~' && (l == 1 || dp[1] == '/'))
+ {
+ char *home;
+
+ home = getenv("HOME");
+ if (home != NULL)
+ {
+ i = strlen(home);
+ if ((fspace -= i) < 0)
+ goto toolong;
+ memcpy(bp, home, i);
+ bp += i;
+ }
+ dp++;
+ l--;
+ }
+ if (l > 0)
+ {
+ if ((fspace -= l) < 0)
+ goto toolong;
+ memcpy(bp, dp, l);
+ bp += l;
+ }
+
+ /* add a "/" between directory and filename */
+ if (ep[-1] != '/')
+ *bp++ = '/';
+ }
+
+ /* now append the file name */
+ i = strlen(fname);
+ if ((fspace -= i) < 0)
+ {
+ toolong:
+ fprintf(stderr, "openpath: pathname too long (ignored)\n");
+ *bp = '\0';
+ fprintf(stderr, "\tDirectory \"%s\"\n", fbuf);
+ fprintf(stderr, "\tFile \"%s\"\n", fname);
+ continue;
+ }
+ memcpy(bp, fname, i + 1);
+
+ if (stat(fbuf, &st) == 0) {
+ if (exe_flag == 0) return fbuf;
+ /* looking for executable */
+#ifdef RUBY
+ if (eaccess(fbuf, X_OK) == 0) return fbuf;
+#else
+ {
+ uid_t uid = getuid();
+ gid_t gid = getgid();
+
+ if (uid == st.st_uid &&
+ (st.st_mode & S_IEXEC) ||
+ gid == st.st_gid &&
+ (st.st_mode & (S_IEXEC>>3)) ||
+ st.st_mode & (S_IEXEC>>6)) {
+ return fbuf;
+ }
+ }
+#endif
+ }
+ /* if not, and no other alternatives, life is bleak */
+ if (*ep == '\0') {
+ dln_errno = DLN_ENOENT;
+ return NULL;
+ }
+
+ /* otherwise try the next component in the search path */
+ }
+}
+
+#ifdef USE_DLN
+
+#include "st.h"
+#include <ar.h>
+#include <a.out.h>
+#ifndef N_COMM
+# define N_COMM 0x12
+#endif
+
+#define INVALID_OBJECT(h) (N_MAGIC(h) != OMAGIC)
+
+static st_table *sym_tbl;
+static st_table *undef_tbl;
+
+static int
+dln_load_header(fd, hdrp, disp)
+ int fd;
+ struct exec *hdrp;
+ long disp;
+{
+ int size;
+
+ lseek(fd, disp, 0);
+ size = read(fd, hdrp, sizeof(*hdrp));
+ if (size == -1) {
+ dln_errno = errno;
+ return -1;
+ }
+ if (size != sizeof(*hdrp) || N_BADMAG(*hdrp)) {
+ dln_errno = DLN_ENOEXEC;
+ return -1;
+ }
+ return 0;
+}
+
+#if defined(sun) && defined(sparc)
+/* Sparc (Sun 4) macros */
+# undef relocation_info
+# define relocation_info reloc_info_sparc
+# define R_RIGHTSHIFT(r) (reloc_r_rightshift[(r)->r_type])
+# define R_BITSIZE(r) (reloc_r_bitsize[(r)->r_type])
+# define R_LENGTH(r) (reloc_r_length[(r)->r_type])
+static int reloc_r_rightshift[] = {
+ 0, 0, 0, 0, 0, 0, 2, 2, 10, 0, 0, 0, 0, 0, 0,
+};
+static int reloc_r_bitsize[] = {
+ 8, 16, 32, 8, 16, 32, 30, 22, 22, 22, 13, 10, 32, 32, 16,
+};
+static int reloc_r_length[] = {
+ 0, 1, 2, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+};
+# define R_PCREL(r) \
+ ((r)->r_type >= RELOC_DISP8 && (r)->r_type <= RELOC_WDISP22)
+# define R_SYMBOL(r) ((r)->r_index)
+#else
+# define R_LENGTH(r) ((r)->r_length)
+# define R_PCREL(r) ((r)->r_pcrel)
+# define R_SYMBOL(r) ((r)->r_symbolnum)
+#endif
+
+static struct relocation_info *
+dln_load_reloc(fd, hdrp, disp)
+ int fd;
+ struct exec *hdrp;
+ long disp;
+{
+ struct relocation_info * reloc;
+ int size;
+
+ lseek(fd, disp + N_TXTOFF(*hdrp) + hdrp->a_text + hdrp->a_data, 0);
+
+ size = hdrp->a_trsize + hdrp->a_drsize;
+ reloc = (struct relocation_info*)xmalloc(size);
+ if (reloc == NULL) {
+ dln_errno = errno;
+ return NULL;
+ }
+
+ if (read(fd, reloc, size) != size) {
+ dln_errno = errno;
+ free(reloc);
+ return NULL;
+ }
+
+ return reloc;
+}
+
+static struct nlist *
+dln_load_sym(fd, hdrp, disp)
+ int fd;
+ struct exec *hdrp;
+ long disp;
+{
+ struct nlist * buffer;
+ struct nlist * sym;
+ struct nlist * end;
+ long displ;
+ int size;
+ st_table *tbl;
+
+ lseek(fd, N_SYMOFF(*hdrp) + hdrp->a_syms + disp, 0);
+ if (read(fd, &size, sizeof(int)) != sizeof(int)) {
+ goto err_noexec;
+ }
+
+ buffer = (struct nlist*)xmalloc(hdrp->a_syms + size);
+ if (buffer == NULL) {
+ dln_errno = errno;
+ return NULL;
+ }
+
+ lseek(fd, disp + N_SYMOFF(*hdrp), 0);
+ if (read(fd, buffer, hdrp->a_syms + size) != hdrp->a_syms + size) {
+ free(buffer);
+ goto err_noexec;
+ }
+
+ sym = buffer;
+ end = sym + hdrp->a_syms / sizeof(struct nlist);
+ displ = (long)buffer + (long)(hdrp->a_syms);
+
+ while (sym < end) {
+ sym->n_un.n_name = (char*)sym->n_un.n_strx + displ;
+ sym++;
+ }
+ return buffer;
+
+ err_noexec:
+ dln_errno = DLN_ENOEXEC;
+ return NULL;
+}
+
+static st_table *
+dln_sym_hash(hdrp, syms)
+ struct exec *hdrp;
+ struct nlist *syms;
+{
+ st_table *tbl;
+ struct nlist *sym = syms;
+ struct nlist *end = syms + (hdrp->a_syms / sizeof(struct nlist));
+
+ tbl = st_init_table(strcmp, st_strhash);
+ if (tbl == NULL) {
+ dln_errno = errno;
+ return NULL;
+ }
+
+ while (sym < end) {
+ st_insert(tbl, sym->n_un.n_name, sym);
+ sym++;
+ }
+ return tbl;
+}
+
+int
+dln_init(prog)
+ char *prog;
+{
+ char *file;
+ int fd, size;
+ struct exec hdr;
+ struct nlist *syms;
+
+ if (dln_init_p == 1) return;
+
+ file = dln_find_exe(prog, NULL);
+ if (file == NULL) return -1;
+ if ((fd = open(file, O_RDONLY)) < 0) {
+ dln_errno = errno;
+ return -1;
+ }
+
+ if (dln_load_header(fd, &hdr, 0) == -1) return -1;
+ syms = dln_load_sym(fd, &hdr, 0);
+ if (syms == NULL) {
+ close(fd);
+ return -1;
+ }
+ sym_tbl = dln_sym_hash(&hdr, syms);
+ if (sym_tbl == NULL) { /* file may be start with #! */
+ char c = '\0';
+ char buf[MAXPATHLEN];
+ char *p;
+
+ free(syms);
+ lseek(fd, 0L, 0);
+ if (read(fd, &c, 1) == -1) {
+ dln_errno = errno;
+ return -1;
+ }
+ if (c != '#') goto err_noexec;
+ if (read(fd, &c, 1) == -1) {
+ dln_errno = errno;
+ return -1;
+ }
+ if (c != '!') goto err_noexec;
+
+ p = buf;
+ /* skip forwading spaces */
+ while (read(fd, &c, 1) == 1) {
+ if (c == '\n') goto err_noexec;
+ if (c != '\t' && c != ' ') {
+ *p++ = c;
+ break;
+ }
+ }
+ /* read in command name */
+ while (read(fd, p, 1) == 1) {
+ if (*p == '\n' || *p == '\t' || *p == ' ') break;
+ p++;
+ }
+ *p = '\0';
+ printf("%s\n", buf);
+
+ return dln_init(buf);
+ }
+ dln_init_p = 1;
+ undef_tbl = st_init_table(strcmp, st_strhash);
+ close(fd);
+ return 0;
+
+ err_noexec:
+ close(fd);
+ dln_errno = DLN_ENOEXEC;
+ return -1;
+}
+
+long
+dln_load_text_data(fd, hdrp, bss, disp)
+ int fd;
+ struct exec *hdrp;
+ int bss;
+ long disp;
+{
+ int size;
+ unsigned char* addr;
+
+ lseek(fd, disp + N_TXTOFF(*hdrp), 0);
+ size = hdrp->a_text + hdrp->a_data;
+
+ if (bss == -1) size += hdrp->a_bss;
+ else if (bss > 1) size += bss;
+
+ addr = (unsigned char*)xmalloc(size);
+ if (addr == NULL) {
+ dln_errno = errno;
+ return 0;
+ }
+
+ if (read(fd, addr, size) != size) {
+ dln_errno = errno;
+ free(addr);
+ return 0;
+ }
+
+ if (bss == -1) {
+ bzero(addr + hdrp->a_text + hdrp->a_data, hdrp->a_bss);
+ }
+ else if (bss > 0) {
+ bzero(addr + hdrp->a_text + hdrp->a_data, bss );
+ }
+
+ return (long)addr;
+}
+
+static int
+undef_print(key, value, arg)
+ char *key;
+{
+ fprintf(stderr, " %s\n", key);
+ return ST_CONTINUE;
+}
+
+static
+dln_undefined()
+{
+ fprintf(stderr, "dln: Calling undefined function\n");
+ fprintf(stderr, " Undefined symbols:\n");
+ st_foreach(undef_tbl, undef_print, NULL);
+#ifdef RUBY
+ rb_exit(1);
+#else
+ exit(1);
+#endif
+}
+
+struct undef {
+ char *name;
+ struct relocation_info reloc;
+ long base;
+ char *addr;
+ union {
+ char c;
+ short s;
+ long l;
+ } u;
+};
+
+static st_table *reloc_tbl = NULL;
+static void
+link_undef(name, base, reloc)
+ char *name;
+ long base;
+ struct relocation_info *reloc;
+{
+ static int u_no = 0;
+ struct undef *obj;
+ char *addr = (char*)(reloc->r_address + base);
+
+ obj = (struct undef*)xmalloc(sizeof(struct undef));
+ obj->name = strdup(name);
+ obj->reloc = *reloc;
+ obj->base = base;
+ switch (R_LENGTH(reloc)) {
+ case 0: /* byte */
+ obj->u.c = *addr;
+ break;
+ case 1: /* word */
+ obj->u.s = *(short*)addr;
+ break;
+ case 2: /* long */
+ obj->u.l = *(long*)addr;
+ break;
+ }
+ if (reloc_tbl == NULL) {
+ reloc_tbl = st_init_table(ST_NUMCMP, ST_NUMHASH);
+ }
+ st_insert(reloc_tbl, u_no++, obj);
+}
+
+struct reloc_arg {
+ char *name;
+ long value;
+};
+
+static int
+reloc_undef(no, undef, arg)
+ int no;
+ struct undef *undef;
+ struct reloc_arg *arg;
+{
+ int datum;
+ char *address;
+#if defined(sun) && defined(sparc)
+ unsigned int mask = 0;
+#endif
+
+ if (strcmp(arg->name, undef->name) != 0) return ST_CONTINUE;
+ address = (char*)(undef->base + undef->reloc.r_address);
+ datum = arg->value;
+
+ if (R_PCREL(&(undef->reloc))) datum -= undef->base;
+#if defined(sun) && defined(sparc)
+ datum += undef->reloc.r_addend;
+ datum >>= R_RIGHTSHIFT(&(undef->reloc));
+ mask = 1 << R_BITSIZE(&(undef->reloc)) - 1;
+ mask |= mask -1;
+ datum &= mask;
+ switch (R_LENGTH(&(undef->reloc))) {
+ case 0:
+ *address = undef->u.c;
+ *address &= ~mask;
+ *address |= datum;
+ break;
+ case 1:
+ *(short *)address = undef->u.s;
+ *(short *)address &= ~mask;
+ *(short *)address |= datum;
+ break;
+ case 2:
+ *(long *)address = undef->u.l;
+ *(long *)address &= ~mask;
+ *(long *)address |= datum;
+ break;
+ }
+#else
+ switch (R_LENGTH(&(undef->reloc))) {
+ case 0: /* byte */
+ *address = undef->u.c + datum;
+ break;
+ case 1: /* word */
+ *(short *)address = undef->u.s + datum;
+ break;
+ case 2: /* long */
+ *(long *)address = undef->u.l + datum;
+ break;
+ }
+#endif
+ free(undef->name);
+ free(undef);
+ return ST_DELETE;
+}
+
+static int
+unlink_undef(name, value)
+ char *name;
+ long value;
+{
+ struct reloc_arg arg;
+
+ arg.name = name;
+ arg.value = value;
+ st_foreach(reloc_tbl, reloc_undef, &arg);
+}
+
+static int dln_load_1(fd, disp, need_init)
+ int fd;
+ long disp;
+ int need_init;
+{
+ static char *libc = LIBC_NAME;
+ struct exec hdr;
+ struct relocation_info *reloc = NULL;
+ long block = 0;
+ long new_common = 0; /* Length of new common */
+ struct nlist *syms = NULL;
+ struct nlist *sym;
+ struct nlist *end;
+ int init_p = 0;
+
+ if (dln_load_header(fd, &hdr, disp) == -1) return -1;
+ if (INVALID_OBJECT(hdr)) {
+ dln_errno = DLN_ENOEXEC;
+ return -1;
+ }
+ reloc = dln_load_reloc(fd, &hdr, disp);
+ if (reloc == NULL) return -1;
+ syms = dln_load_sym(fd, &hdr, disp);
+ if (syms == NULL) return -1;
+
+ sym = syms;
+ end = syms + (hdr.a_syms / sizeof(struct nlist));
+ while (sym < end) {
+ struct nlist *old_sym;
+ int value = sym->n_value;
+
+ if (sym->n_type == (N_UNDF | N_EXT)) {
+ if (st_lookup(sym_tbl, sym->n_un.n_name, &old_sym) == 0) {
+ old_sym = NULL;
+ }
+
+ if (value) {
+ if (old_sym) {
+ sym->n_type = N_EXT | N_COMM;
+ sym->n_value = old_sym->n_value;
+ }
+ else {
+ int rnd =
+ value >= sizeof(double) ? sizeof(double) - 1
+ : value >= sizeof(long) ? sizeof(long) - 1
+ : sizeof(short) - 1;
+
+ sym->n_type = N_COMM;
+ new_common += rnd;
+ new_common &= ~(long)rnd;
+ sym->n_value = new_common;
+ new_common += value;
+ }
+ }
+ else {
+ if (old_sym) {
+ sym->n_type = N_EXT | N_COMM;
+ sym->n_value = old_sym->n_value;
+ }
+ else {
+ sym->n_value = (long)dln_undefined;
+ st_insert(undef_tbl, strdup(sym->n_un.n_name), NULL);
+ }
+ }
+ }
+ sym++;
+ }
+
+ block = dln_load_text_data(fd, &hdr, hdr.a_bss + new_common, disp);
+ if (block == 0) goto err_exit;
+
+ sym = syms;
+ while (sym < end) {
+ struct nlist *new_sym;
+ char *key;
+
+ switch (sym->n_type) {
+ case N_COMM:
+ sym->n_value += hdr.a_text + hdr.a_data;
+ case N_TEXT|N_EXT:
+ case N_DATA|N_EXT:
+ sym->n_value += block;
+
+ if (st_lookup(sym_tbl, sym->n_un.n_name, &new_sym) != 0
+ && new_sym->n_value != (long)dln_undefined) {
+ dln_errno = DLN_ECONFL;
+ goto err_exit;
+ }
+
+ key = sym->n_un.n_name;
+ if (st_delete(undef_tbl, &key, NULL) != 0) {
+ unlink_undef(key, sym->n_value);
+ free(key);
+ }
+
+ new_sym = (struct nlist*)xmalloc(sizeof(struct nlist));
+ *new_sym = *sym;
+ new_sym->n_un.n_name = strdup(sym->n_un.n_name);
+ st_insert(sym_tbl, new_sym->n_un.n_name, new_sym);
+ }
+ sym++;
+ }
+
+ /*
+ * First comes the text-relocation
+ */
+ {
+ struct relocation_info * rel = reloc;
+ struct relocation_info * rel_beg = reloc +
+ (hdr.a_trsize/sizeof(struct relocation_info));
+ struct relocation_info * rel_end = reloc +
+ (hdr.a_trsize+hdr.a_drsize)/sizeof(struct relocation_info);
+
+ while (rel < rel_end) {
+ char *address = (char*)(rel->r_address + block);
+ long datum = 0;
+#if defined(sun) && defined(sparc)
+ unsigned int mask = 0;
+#endif
+
+ if(rel >= rel_beg)
+ address += hdr.a_text;
+
+ if (rel->r_extern) { /* Look it up in symbol-table */
+ sym = &(syms[R_SYMBOL(rel)]);
+ switch (sym->n_type) {
+ case N_EXT|N_UNDF:
+ link_undef(sym->n_un.n_name, block, rel);
+ case N_EXT|N_COMM:
+ case N_COMM:
+ datum = sym->n_value;
+ break;
+ default:
+ goto err_exit;
+ }
+ } /* end.. look it up */
+ else { /* is static */
+ switch (R_SYMBOL(rel) & N_TYPE) {
+ case N_TEXT:
+ case N_DATA:
+ datum = block;
+ break;
+ case N_BSS:
+ datum = block + new_common;
+ break;
+ case N_ABS:
+ break;
+ }
+ } /* end .. is static */
+ if (R_PCREL(rel)) datum -= block;
+
+#if defined(sun) && defined(sparc)
+ datum += rel->r_addend;
+ datum >>= R_RIGHTSHIFT(rel);
+ mask = 1 << R_BITSIZE(rel) - 1;
+ mask |= mask -1;
+ datum &= mask;
+
+ switch (R_LENGTH(rel)) {
+ case 0:
+ *address &= ~mask;
+ *address |= datum;
+ break;
+ case 1:
+ *(short *)address &= ~mask;
+ *(short *)address |= datum;
+ break;
+ case 2:
+ *(long *)address &= ~mask;
+ *(long *)address |= datum;
+ break;
+ }
+#else
+ switch (R_LENGTH(rel)) {
+ case 0: /* byte */
+ if (datum < -128 || datum > 127) goto err_exit;
+ *address += datum;
+ break;
+ case 1: /* word */
+ *(short *)address += datum;
+ break;
+ case 2: /* long */
+ *(long *)address += datum;
+ break;
+ }
+#endif
+ rel++;
+ }
+ }
+
+ if (need_init) {
+ if (undef_tbl->num_entries > 0) {
+ if (dln_load_lib(libc) == -1) goto err_exit;
+ }
+
+ sym = syms;
+ while (sym < end) {
+ char *name = sym->n_un.n_name;
+ if (name[0] == '_' && sym->n_value >= block
+ && ((bcmp (name, "_Init_", 6) == 0
+ || bcmp (name, "_init_", 6) == 0) && name[6] != '_')) {
+ init_p = 1;
+ ((int (*)())sym->n_value)();
+ }
+ sym++;
+ }
+ }
+ free(reloc);
+ free(syms);
+ if (need_init) {
+ if (init_p == 0) {
+ dln_errno = DLN_ENOINIT;
+ return -1;
+ }
+ if (undef_tbl->num_entries > 0) {
+ if (dln_load_lib(libc) == -1) goto err_exit;
+ if (undef_tbl->num_entries > 0) {
+ dln_errno = DLN_EUNDEF;
+ return -1;
+ }
+ }
+ }
+ return 0;
+
+ err_exit:
+ if (syms) free(syms);
+ if (reloc) free(reloc);
+ if (block) free(block);
+ return -1;
+}
+
+int
+dln_load(file)
+ char *file;
+{
+ int fd;
+ int result;
+
+ if (dln_init_p == 0) {
+ dln_errno = DLN_ENOINIT;
+ return -1;
+ }
+
+ fd = open(file, O_RDONLY);
+ if (fd == -1) {
+ dln_errno = errno;
+ return -1;
+ }
+ result = dln_load_1(fd, 0, 1);
+ close(fd);
+
+ return result;
+}
+
+struct symdef {
+ int str_index;
+ int lib_offset;
+};
+
+static int target_offset;
+static int
+search_undef(key, value, lib_tbl)
+ char *key;
+ int value;
+ st_table *lib_tbl;
+{
+ static char *last = "";
+ int offset;
+
+ if (st_lookup(lib_tbl, key, &offset) == 0) return ST_CONTINUE;
+ if (strcmp(last, key) != 0) {
+ last = key;
+ target_offset = offset;
+ }
+ return ST_STOP;
+}
+
+char *dln_library_path = DLN_DEFAULT_PATH;
+
+int
+dln_load_lib(lib)
+ char *lib;
+{
+ char *path, *file;
+ char armagic[SARMAG];
+ int fd, size;
+ struct ar_hdr ahdr;
+ st_table *lib_tbl = NULL;
+ int *data, nsym;
+ struct symdef *base;
+ char *name_base;
+
+ if (dln_init_p == 0) {
+ dln_errno = DLN_ENOINIT;
+ return -1;
+ }
+
+ if (undef_tbl->num_entries == 0) return 0;
+ dln_errno = DLN_EBADLIB;
+
+ /* library search path: */
+ /* look for environment variable DLN_LIBRARY_PATH first. */
+ /* then variable dln_library_path. */
+ /* if path is still NULL, use "." for path. */
+ path = getenv("DLN_LIBRARY_PATH");
+ if (path == NULL) path = dln_library_path;
+
+ file = dln_find_file(lib, path);
+ fd = open(file, O_RDONLY);
+ if (fd == -1) goto syserr;
+ size = read(fd, armagic, SARMAG);
+ if (fd == -1) goto syserr;
+
+ if (size != SARMAG) {
+ dln_errno = DLN_ENOTLIB;
+ goto badlib;
+ }
+ size = read(fd, &ahdr, sizeof(ahdr));
+ if (size == -1) goto syserr;
+ if (size != sizeof(ahdr) || sscanf(ahdr.ar_size, "%d", &size) != 1) {
+ goto badlib;
+ }
+
+ if (strncmp(ahdr.ar_name, "__.SYMDEF", 9) == 0 && ahdr.ar_name[9] == ' ') {
+ /* make hash table from __.SYMDEF */
+
+ lib_tbl = st_init_table(strcmp, st_strhash);
+ data = (int*)xmalloc(size);
+ if (data == NULL) goto syserr;
+ size = read(fd, data, size);
+ nsym = *data / sizeof(struct symdef);
+ base = (struct symdef*)(data + 1);
+ name_base = (char*)(base + nsym) + sizeof(int);
+ while (nsym > 0) {
+ char *name = name_base + base->str_index;
+
+ st_insert(lib_tbl, name, base->lib_offset + sizeof(ahdr));
+ nsym--;
+ base++;
+ }
+ for (;;) {
+ target_offset = -1;
+ st_foreach(undef_tbl, search_undef, lib_tbl);
+ if (target_offset == -1) break;
+ if (dln_load_1(fd, target_offset, 0) == -1) {
+ st_free_table(lib_tbl);
+ free(data);
+ goto badlib;
+ }
+ if (undef_tbl->num_entries == 0) break;
+ }
+ free(data);
+ st_free_table(lib_tbl);
+ }
+ else {
+ /* linear library, need to scan (FUTURE) */
+
+ for (;;) {
+ int offset = SARMAG;
+ int found = 0;
+ struct exec hdr;
+ struct nlist *syms, *sym, *end;
+
+ while (undef_tbl->num_entries > 0) {
+ found = 0;
+ lseek(fd, offset, 0);
+ size = read(fd, &ahdr, sizeof(ahdr));
+ if (size == -1) goto syserr;
+ if (size == 0) break;
+ if (size != sizeof(ahdr)
+ || sscanf(ahdr.ar_size, "%d", &size) != 1) {
+ goto badlib;
+ }
+ offset += sizeof(ahdr);
+ if (dln_load_header(fd, &hdr, offset) == -1)
+ goto badlib;
+ syms = dln_load_sym(fd, &hdr, offset);
+ if (syms == NULL) goto badlib;
+ sym = syms;
+ end = syms + (hdr.a_syms / sizeof(struct nlist));
+ while (sym < end) {
+ if (sym->n_type == N_EXT|N_TEXT
+ && st_lookup(undef_tbl, sym->n_un.n_name, NULL)) {
+ break;
+ }
+ sym++;
+ }
+ if (sym < end) {
+ found++;
+ free(syms);
+ if (dln_load_1(fd, offset, 0) == -1) {
+ goto badlib;
+ }
+ }
+ offset += size;
+ if (offset & 1) offset++;
+ }
+ if (found) break;
+ }
+ }
+ close(fd);
+ return 0;
+
+ syserr:
+ dln_errno = errno;
+ badlib:
+ if (fd >= 0) close(fd);
+ return -1;
+}
+
+char *
+dln_strerror()
+{
+ char *strerror();
+
+ switch (dln_errno) {
+ case DLN_ECONFL:
+ return "Symbol name conflict";
+ case DLN_ENOINIT:
+ return "No inititalizer given";
+ case DLN_EUNDEF:
+ return "Unresolved symbols";
+ case DLN_ENOTLIB:
+ return "Not a library file";
+ case DLN_EBADLIB:
+ return "Malformed library file";
+ case DLN_EINIT:
+ return "Not initialized";
+ default:
+ return strerror(dln_errno);
+ }
+}
+
+dln_perror(str)
+ char *str;
+{
+ fprintf(stderr, "%s: %s\n", str, dln_strerror());
+}
+
+void*
+dln_get_sym(name)
+ char *name;
+{
+ struct nlist *sym;
+
+ if (st_lookup(sym_tbl, name, &sym))
+ return (void*)sym->n_value;
+ return NULL;
+}
+
+#ifdef TEST
+xmalloc(size)
+ int size;
+{
+ return malloc(size);
+}
+
+xcalloc(size, n)
+ int size, n;
+{
+ return calloc(size, n);
+}
+
+main(argc, argv)
+ int argc;
+ char **argv;
+{
+ if (dln_init(argv[0]) == -1) {
+ dln_perror("dln_init");
+ exit(1);
+ }
+
+ while (argc > 1) {
+ printf("obj: %s\n", argv[1]);
+ if (dln_load(argv[1]) == -1) {
+ dln_perror("dln_load");
+ exit(1);
+ }
+ argc--;
+ argv++;
+ }
+ if (dln_load_lib("libdln.a") == -1) {
+ dln_perror("dln_init");
+ exit(1);
+ }
+
+ if (dln_get_sym("_foo"))
+ printf("_foo defined\n");
+ else
+ printf("_foo undefined\n");
+}
+#endif /* TEST */
+
+#else /* USE_DLN */
+
+int
+dln_init(file)
+ char *file;
+{
+ return 0;
+}
+
+int
+dln_load(file)
+ char *file;
+{
+ return 0;
+}
+
+int
+dln_load_lib(file)
+ char *file;
+{
+ return 0;
+}
+
+#endif /* USE_DLN */