/****************************************************************/
/* mdso: midipix dso scavenger */
/* Copyright (C) 2015 Z. Gilboa */
/* Released under GPLv2 and GPLv3; see COPYING.MDSO. */
/****************************************************************/
#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>
#include <mdso/mdso.h>
#include "mdso_driver_impl.h"
static int mdso_free_unit_ctx_impl(struct mdso_unit_ctx_impl * ctx, int status)
{
if (ctx) {
if (ctx->expsyms && ctx->expsyms->buffer)
free(ctx->expsyms->buffer);
if (ctx->expsyms)
free(ctx->expsyms);
mdso_unmap_input(&ctx->map);
free(ctx);
}
return status;
}
static FILE * mdso_stdin_to_tmp(const struct mdso_driver_ctx * dctx)
{
struct mdso_driver_ctx_impl * ictx;
uintptr_t addr;
int fdtmp;
FILE * ftmp;
char buf[4096];
ssize_t nread;
int ret;
addr = (uintptr_t)dctx - offsetof(struct mdso_driver_ctx_impl,ctx);
ictx = (struct mdso_driver_ctx_impl *)addr;
if (ictx->fdtmpin >= 0) {
if ((fdtmp = dup(ictx->fdtmpin)) < 0)
return 0;
if (!(ftmp = fdopen(fdtmp,"r")))
close(fdtmp);
return ftmp;
}
if (!(ftmp = tmpfile()))
return 0;
if ((ictx->fdtmpin = dup(fileno(ftmp))) < 0) {
fclose(ftmp);
return 0;
}
nread = read(0,buf,sizeof(buf)-1);
while (nread) {
if (nread > 0) {
buf[nread] = '\0';
ret = fputs(buf,ftmp);
} else
ret = (errno == EINTR) ? 0 : -1;
if (ret < 0) {
fclose(ftmp);
return 0;
}
nread = read(0,buf,sizeof(buf)-1);
}
return ftmp;
}
static int mdso_create_symbol_vector(struct mdso_unit_ctx_impl * ctx)
{
int nsyms;
size_t nbytes;
size_t size;
char * dst;
const char * ch;
const char ** sym;
const char exphdr[] = "EXPORTS\n";
const char imphdr[] = "IMPORTS\n";
ch = ctx->map.addr;
nbytes = ctx->map.size;
for (nsyms=0; nbytes; ch++,nbytes--)
nsyms += (*ch == '\n');
size = offsetof(struct mdso_unit_ctx_impl,expsyms);
size += (nsyms+1)*sizeof(const char *);
if (!(ctx->expsyms = calloc(1,size)))
return -1;
if (!(ctx->expsyms->buffer = calloc(1,ctx->map.size)))
return -1;
ch = ctx->map.addr;
nbytes = ctx->map.size;
sym = ctx->expsyms->syms;
dst = ctx->expsyms->buffer;
size = strlen(exphdr);
/* support .def input files */
if ((nbytes >= size) && !(strncmp(ch,exphdr,size))) {
ch += size;
nbytes -= size;
}
/* advance to first symbol */
for (; nbytes && ((*ch==' ')
|| (*ch=='\t')
|| (*ch=='\r')
|| (*ch=='\n')); nbytes--)
ch++;
/* support .def input files */
size = strlen(imphdr);
while (nbytes && ((nbytes < size) || (strncmp(ch,imphdr,size)))) {
/* vector */
*sym++ = dst;
/* symbol */
for (; nbytes && ((*ch!=' ')
&& (*ch!='\t')
&& (*ch!='\r')
&& (*ch!='\n')); nbytes--)
*dst++ = *ch++;
dst++;
/* discard rest of input line */
for (; nbytes && (*ch!='\n'); nbytes--)
ch++;
/* advance to next symbol */
for (; nbytes && ((*ch==' ')
|| (*ch=='\t')
|| (*ch=='\r')
|| (*ch=='\n')); nbytes--)
ch++;
}
return 0;
}
int mdso_get_unit_ctx(
const struct mdso_driver_ctx * dctx,
const char * path,
struct mdso_unit_ctx ** pctx)
{
struct mdso_unit_ctx_impl * ctx;
FILE * ftmp;
int fd;
if (!dctx || !(ctx = calloc(1,sizeof(*ctx))))
return -1;
if (strcmp(path,"-"))
fd = -1;
else if (!(ftmp = mdso_stdin_to_tmp(dctx)))
return mdso_free_unit_ctx_impl(ctx,-1);
else if ((fd = dup(fileno(ftmp))) < 0)
return mdso_free_unit_ctx_impl(ctx,-1);
else
fclose(ftmp);
if (mdso_map_input(fd,path,PROT_READ,&ctx->map))
return mdso_free_unit_ctx_impl(ctx,-1);
if (fd > 0)
close(fd);
if (mdso_create_symbol_vector(ctx))
return mdso_free_unit_ctx_impl(ctx,-1);
memcpy(&ctx->cctx,dctx->cctx,
sizeof(ctx->cctx));
ctx->path = path;
ctx->uctx.path = &ctx->path;
ctx->uctx.map = &ctx->map;
ctx->uctx.cctx = &ctx->cctx;
ctx->uctx.syms = ctx->expsyms->syms;
*pctx = &ctx->uctx;
return 0;
}
void mdso_free_unit_ctx(struct mdso_unit_ctx * ctx)
{
struct mdso_unit_ctx_impl * ictx;
uintptr_t addr;
if (ctx) {
addr = (uintptr_t)ctx - offsetof(struct mdso_unit_ctx_impl,uctx);
ictx = (struct mdso_unit_ctx_impl *)addr;
mdso_free_unit_ctx_impl(ictx,0);
}
}