private-lib: add src/fldd

2 files changed, 307 insertions, 0 deletions

diff --git a/src/fldd/Makefile.in b/src/fldd/Makefile.in
new file mode 100644
index 000000000..7369c835b
--- /dev/null
+++ b/src/fldd/Makefile.in
@@ -0,0 +1,45 @@
+all: fldd
+
+CC=@CC@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+sysconfdir=@sysconfdir@
+
+VERSION=@PACKAGE_VERSION@
+NAME=@PACKAGE_NAME@
+HAVE_SECCOMP_H=@HAVE_SECCOMP_H@
+HAVE_SECCOMP=@HAVE_SECCOMP@
+HAVE_CHROOT=@HAVE_CHROOT@
+HAVE_BIND=@HAVE_BIND@
+HAVE_FATAL_WARNINGS=@HAVE_FATAL_WARNINGS@
+HAVE_NETWORK=@HAVE_NETWORK@
+HAVE_USERNS=@HAVE_USERNS@
+HAVE_X11=@HAVE_X11@
+HAVE_FILE_TRANSFER=@HAVE_FILE_TRANSFER@
+HAVE_WHITELIST=@HAVE_WHITELIST@
+HAVE_GLOBALCFG=@HAVE_GLOBALCFG@
+HAVE_APPARMOR=@HAVE_APPARMOR@
+HAVE_OVERLAYFS=@HAVE_OVERLAYFS@
+HAVE_PRIVATE_HOME=@HAVE_PRIVATE_HOME@
+EXTRA_LDFLAGS +=@EXTRA_LDFLAGS@
+HAVE_GCOV=@HAVE_GCOV@
+EXTRA_LDFLAGS +=@EXTRA_LDFLAGS@
+
+H_FILE_LIST       = $(sort $(wildcard *.[h]))
+C_FILE_LIST       = $(sort $(wildcard *.c))
+OBJS = $(C_FILE_LIST:.c=.o)
+BINOBJS =  $(foreach file, $(OBJS), $file)
+CFLAGS += -ggdb $(HAVE_FATAL_WARNINGS) -O2 -DVERSION='"$(VERSION)"' $(HAVE_GCOV) -DPREFIX='"$(prefix)"'  -DSYSCONFDIR='"$(sysconfdir)/firejail"' -DLIBDIR='"$(libdir)"' $(HAVE_X11) $(HAVE_PRIVATE_HOME) $(HAVE_APPARMOR) $(HAVE_OVERLAYFS) $(HAVE_SECCOMP) $(HAVE_GLOBALCFG) $(HAVE_SECCOMP_H) $(HAVE_CHROOT) $(HAVE_NETWORK) $(HAVE_USERNS) $(HAVE_BIND) $(HAVE_FILE_TRANSFER) $(HAVE_WHITELIST) -fstack-protector-all -D_FORTIFY_SOURCE=2 -fPIE -pie -Wformat -Wformat-security
+LDFLAGS += -pie -Wl,-z,relro -Wl,-z,now -lpthread
+
+%.o : %.c $(H_FILE_LIST) ../include/common.h ../include/syscall.h
+        $(CC) $(CFLAGS) $(INCLUDE) -c $< -o $@
+
+fldd: $(OBJS)
+        $(CC)  $(LDFLAGS) -o $@ $(OBJS) $(LIBS) $(EXTRA_LDFLAGS)
+
+clean:; rm -f *.o fldd *.gcov *.gcda *.gcno
+
+distclean: clean
+        rm -fr Makefile
diff --git a/src/fldd/main.c b/src/fldd/main.c
new file mode 100644
index 000000000..8b54242a4
--- /dev/null
+++ b/src/fldd/main.c
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2014-2017 netblue30 (netblue30@yahoo.com)
+ *
+ * This file is part of firejail project
+ *
+ * This program 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 2 of the License, 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; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "../include/common.h"
+
+#include <elf.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#ifdef __LP64__
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Phdr Elf64_Phdr
+#define Elf_Shdr Elf64_Shdr
+#define Elf_Dyn Elf64_Dyn
+#else
+#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Phdr Elf32_Phdr
+#define Elf_Shdr Elf32_Shdr
+#define Elf_Dyn Elf32_Dyn
+#endif
+
+static int arg_quiet = 0;
+static void copy_libs_for_lib(const char *lib);
+
+static const char * const lib_paths[] = {
+        "/lib",
+        "/lib/x86_64-linux-gnu",
+        "/lib64",
+        "/usr/lib",
+        "/usr/lib/x86_64-linux-gnu",
+        LIBDIR,
+        "/usr/local/lib",
+        NULL
+}; // Note: this array is duplicated in src/firejail/fs_lib.c
+
+
+typedef struct storage_t {
+        struct storage_t *next;
+        const char *name;
+} Storage;
+static Storage *head;
+
+// return 1 if found
+static int storage_find(const char *name) {
+        Storage *ptr = head;
+        
+        while (ptr) {
+                if (strcmp(ptr->name, name) == 0)
+                        return 1;
+                ptr = ptr->next;
+        }
+
+        return 0;
+}
+
+static void storage_add(const char *name) {
+        if (storage_find(name))
+                return;
+
+        Storage *s = malloc(sizeof(Storage));
+        if (!s)
+                errExit("malloc");
+        s->next = head;
+        head = s;
+        s->name = strdup(name);
+        if (!s->name)
+                errExit("strdup");
+}
+
+
+static void storage_print(int fd) {
+        Storage *ptr = head;
+        
+        while (ptr) {
+                dprintf(fd, "%s\n", ptr->name);
+                ptr = ptr->next;
+        }
+}
+
+
+
+static void copy_libs_for_exe(const char *exe) {
+        int f;
+        f = open(exe, O_RDONLY);
+        if (f < 0) {
+                if (!arg_quiet)
+                        fprintf(stderr, "Warning fldd: cannot open %s\n", exe);
+                return;
+        }
+        
+        struct stat s;
+        char *base = NULL;
+        if (fstat(f, &s) == -1)
+                goto error_close;
+        base = mmap(0, s.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, f, 0);
+        if (base == MAP_FAILED)
+                goto error_close;
+
+
+        Elf_Ehdr *ebuf = (Elf_Ehdr *)base;
+        if (strncmp((const char *)ebuf->e_ident, ELFMAG, SELFMAG) != 0) {
+                if (!arg_quiet)
+                        fprintf(stderr, "Warning fldd: %s is not an ELF executable or library\n", exe);
+                goto close;
+        }
+
+        Elf_Phdr *pbuf = (Elf_Phdr *)(base + sizeof(*ebuf));
+        while (ebuf->e_phnum-- > 0) {
+                switch (pbuf->p_type) {
+                case PT_INTERP:
+                        // dynamic loader ld-linux.so
+                        storage_add(base + pbuf->p_offset);
+                        break;
+                }
+                pbuf++;
+        }
+
+        Elf_Shdr *sbuf = (Elf_Shdr *)(base + ebuf->e_shoff);
+
+        // Find strings section
+        char *strbase = NULL;
+        int sections = ebuf->e_shnum;
+        while (sections-- > 0) {
+                if (sbuf->sh_type == SHT_STRTAB) {
+                        strbase = base + sbuf->sh_offset;
+                        break;
+                }
+                sbuf++;
+        }
+        if (strbase == NULL)
+                goto error_close;
+
+        // Find dynamic section
+        sections = ebuf->e_shnum;
+        while (sections-- > 0) {
+// TODO: running fldd on large gui programs (fldd /usr/bin/transmission-qt)
+// crash on accessing memory location sbuf->sh_type if sbuf->sh_type in the previous section was 0 (SHT_NULL)
+// for now we just exit the while loop - this is probably incorrect
+// printf("sbuf %p #%s#, sections %d, type %u\n", sbuf, exe, sections, sbuf->sh_type);
+                if (sbuf->sh_type == SHT_NULL)
+                        break;
+                if (sbuf->sh_type == SHT_DYNAMIC) {
+                        // Find DT_NEEDED tags
+                        Elf_Dyn *dbuf = (Elf_Dyn *)(base + sbuf->sh_offset);
+                        while (sbuf->sh_size >= sizeof(*dbuf)) {
+                                if (dbuf->d_tag == DT_NEEDED) {
+                                        const char *lib = strbase + dbuf->d_un.d_ptr;
+                                        copy_libs_for_lib(lib);
+                                }
+                                sbuf->sh_size -= sizeof(*dbuf);
+                                dbuf++;
+                        }
+                }
+                sbuf++;
+        }
+        goto close;
+
+ error_close:
+        perror("copy libs");
+ close:
+        if (base)
+                munmap(base, s.st_size);
+                        
+        close(f);
+}
+
+static void copy_libs_for_lib(const char *lib) {
+        int i;
+        for (i = 0; lib_paths[i]; i++) {
+                char *fname;
+                if (asprintf(&fname, "%s/%s", lib_paths[i], lib) == -1)
+                        errExit("asprintf");
+                if (access(fname, R_OK) == 0) {
+                        if (!storage_find(fname)) {
+                                storage_add(fname);
+                                // libs may need other libs
+                                copy_libs_for_exe(fname);
+                        }
+                        free(fname);
+                        return;
+                }
+                free(fname);
+        }
+        errExit("library not found");
+}
+
+static void usage(void) {
+        printf("Usage: fldd program [file]\n");
+        printf("print a list of libraries used by program or store it in the file.\n");
+}
+
+int main(int argc, char **argv) {
+#if 0
+{
+//system("cat /proc/self/status");
+int i;
+for (i = 0; i < argc; i++)
+        printf("*%s* ", argv[i]);
+printf("\n");
+}
+#endif
+        if (argc < 2) {
+                fprintf(stderr, "Error fldd: invalid arguments\n");
+                usage();
+                exit(1);
+        }
+
+
+        // check program access
+        if (access(argv[1], R_OK)) {
+                fprintf(stderr, "Error fldd: cannot access %s\n", argv[1]);
+                exit(1);
+        }
+
+        char *quiet = getenv("FIREJAIL_QUIET");
+        if (quiet && strcmp(quiet, "yes") == 0)
+                arg_quiet = 1;
+
+        if (strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") ==0) {
+                usage();
+                return 0;
+        }
+        
+        int fd = STDOUT_FILENO;
+        // attempt to open the file
+        if (argc == 3) {
+                fd = open(argv[2], O_CREAT | O_TRUNC | O_WRONLY, 0644);
+                if (!fd) {
+                        fprintf(stderr, "Error fldd: invalid arguments\n");
+                        usage();
+                        exit(1);
+                }
+        }
+        
+        copy_libs_for_exe(argv[1]);
+        storage_print(fd);      
+        if (argc == 3)
+                close(fd);
+                
+        return 0;
+}