Commit 77cb17e9 authored by Michal Ostrowski's avatar Michal Ostrowski Committed by Junio C Hamano

Exec git programs without using PATH.

The git suite may not be in PATH (and thus programs such as
git-send-pack could not exec git-rev-list).  Thus there is a need for
logic that will locate these programs.  Modifying PATH is not
desirable as it result in behavior differing from the user's
intentions, as we may end up prepending "/usr/bin" to PATH.

- git C programs will use exec*_git_cmd() APIs to exec sub-commands.
- exec*_git_cmd() will execute a git program by searching for it in
  the following directories:
	1. --exec-path (as used by "git")
	2. The GIT_EXEC_PATH environment variable.
	3. $(gitexecdir) as set in Makefile (default value $(bindir)).
- git wrapper will modify PATH as before to enable shell scripts to
  invoke "git-foo" commands.

Ideally, shell scripts should use the git wrapper to become independent
of PATH, and then modifying PATH will not be necessary.

[jc: with minor updates after a brief review.]
Signed-off-by: default avatarMichal Ostrowski <mostrows@watson.ibm.com>
Signed-off-by: default avatarJunio C Hamano <junkio@cox.net>
parent c884dd9a
......@@ -69,6 +69,7 @@ STRIP ?= strip
prefix = $(HOME)
bindir = $(prefix)/bin
gitexecdir = $(prefix)/bin
template_dir = $(prefix)/share/git-core/templates/
GIT_PYTHON_DIR = $(prefix)/share/git-core/python
# DESTDIR=
......@@ -142,7 +143,7 @@ PROGRAMS = \
git-describe$X
# what 'all' will build and 'install' will install.
ALL_PROGRAMS = $(PROGRAMS) $(SIMPLE_PROGRAMS) $(SCRIPTS) git$X
ALL_PROGRAMS = $(PROGRAMS) $(SIMPLE_PROGRAMS) $(SCRIPTS)
# Backward compatibility -- to be removed after 1.0
PROGRAMS += git-ssh-pull$X git-ssh-push$X
......@@ -174,7 +175,7 @@ DIFF_OBJS = \
LIB_OBJS = \
blob.o commit.o connect.o count-delta.o csum-file.o \
date.o diff-delta.o entry.o ident.o index.o \
date.o diff-delta.o entry.o exec_cmd.o ident.o index.o \
object.o pack-check.o patch-delta.o path.o pkt-line.o \
quote.o read-cache.o refs.o run-command.o \
server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
......@@ -367,7 +368,7 @@ LIB_OBJS += $(COMPAT_OBJS)
export prefix TAR INSTALL DESTDIR SHELL_PATH template_dir
### Build rules
all: $(ALL_PROGRAMS)
all: $(ALL_PROGRAMS) git$X
all:
$(MAKE) -C templates
......@@ -376,7 +377,7 @@ strip: $(PROGRAMS) git$X
$(STRIP) $(STRIP_OPTS) $(PROGRAMS) git$X
git$X: git.c $(LIB_FILE)
$(CC) -DGIT_EXEC_PATH='"$(bindir)"' -DGIT_VERSION='"$(GIT_VERSION)"' \
$(CC) -DGIT_VERSION='"$(GIT_VERSION)"' \
$(CFLAGS) $(COMPAT_CFLAGS) -o $@ $(filter %.c,$^) $(LIB_FILE)
$(patsubst %.sh,%,$(SCRIPT_SH)) : % : %.sh
......@@ -416,6 +417,8 @@ git$X git.spec \
%.o: %.S
$(CC) -o $*.o -c $(ALL_CFLAGS) $<
exec_cmd.o: ALL_CFLAGS += -DGIT_EXEC_PATH=\"$(gitexecdir)\"
git-%$X: %.o $(LIB_FILE)
$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
......@@ -472,7 +475,9 @@ check:
install: all
$(INSTALL) -d -m755 $(call shellquote,$(DESTDIR)$(bindir))
$(INSTALL) -d -m755 $(call shellquote,$(DESTDIR)$(gitexecdir))
$(INSTALL) $(ALL_PROGRAMS) $(call shellquote,$(DESTDIR)$(bindir))
$(INSTALL) git$X $(call shellquote,$(DESTDIR)$(gitexecdir))
$(MAKE) -C templates install
$(INSTALL) -d -m755 $(call shellquote,$(DESTDIR)$(GIT_PYTHON_DIR))
$(INSTALL) $(PYMODULES) $(call shellquote,$(DESTDIR)$(GIT_PYTHON_DIR))
......
......@@ -9,6 +9,7 @@
#include <syslog.h>
#include "pkt-line.h"
#include "cache.h"
#include "exec_cmd.h"
static int log_syslog;
static int verbose;
......@@ -227,7 +228,7 @@ static int upload(char *dir)
snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
/* git-upload-pack only ever reads stuff, so this is safe */
execlp("git-upload-pack", "git-upload-pack", "--strict", timeout_buf, ".", NULL);
execl_git_cmd("upload-pack", "--strict", timeout_buf, ".", NULL);
return -1;
}
......
#include "cache.h"
#include "exec_cmd.h"
#define MAX_ARGS 32
extern char **environ;
static const char *builtin_exec_path = GIT_EXEC_PATH;
static const char *current_exec_path = NULL;
void git_set_exec_path(const char *exec_path)
{
current_exec_path = exec_path;
}
/* Returns the highest-priority, location to look for git programs. */
const char *git_exec_path()
{
const char *env;
if (current_exec_path)
return current_exec_path;
env = getenv("GIT_EXEC_PATH");
if (env) {
return env;
}
return builtin_exec_path;
}
int execv_git_cmd(char **argv)
{
char git_command[PATH_MAX + 1];
char *tmp;
int len, err, i;
const char *paths[] = { current_exec_path,
getenv("GIT_EXEC_PATH"),
builtin_exec_path };
for (i = 0; i < sizeof(paths)/sizeof(paths[0]); ++i) {
const char *exec_dir = paths[i];
if (!exec_dir) continue;
if (*exec_dir != '/') {
if (!getcwd(git_command, sizeof(git_command))) {
fprintf(stderr, "git: cannot determine "
"current directory\n");
exit(1);
}
len = strlen(git_command);
/* Trivial cleanup */
while (!strncmp(exec_dir, "./", 2)) {
exec_dir += 2;
while (*exec_dir == '/')
exec_dir++;
}
snprintf(git_command + len, sizeof(git_command) - len,
"/%s", exec_dir);
} else {
strcpy(git_command, exec_dir);
}
len = strlen(git_command);
len += snprintf(git_command + len, sizeof(git_command) - len,
"/git-%s", argv[0]);
if (sizeof(git_command) <= len) {
fprintf(stderr,
"git: command name given is too long.\n");
break;
}
/* argv[0] must be the git command, but the argv array
* belongs to the caller, and my be reused in
* subsequent loop iterations. Save argv[0] and
* restore it on error.
*/
tmp = argv[0];
argv[0] = git_command;
/* execve() can only ever return if it fails */
execve(git_command, argv, environ);
err = errno;
argv[0] = tmp;
}
return -1;
}
int execl_git_cmd(char *cmd,...)
{
int argc;
char *argv[MAX_ARGS + 1];
char *arg;
va_list param;
va_start(param, cmd);
argv[0] = cmd;
argc = 1;
while (argc < MAX_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_ARGS <= argc)
return error("too many args to run %s", cmd);
argv[argc] = NULL;
return execv_git_cmd(argv);
}
#ifndef __GIT_EXEC_CMD_H_
#define __GIT_EXEC_CMD_H_
extern void git_set_exec_path(const char *exec_path);
extern const char* git_exec_path(void);
extern int execv_git_cmd(char **argv); /* NULL terminated */
extern int execl_git_cmd(char *cmd, ...);
#endif /* __GIT_EXEC_CMD_H_ */
#include "cache.h"
#include "exec_cmd.h"
#include <sys/wait.h>
static int finish_pack(const char *pack_tmp_name, const char *me)
......@@ -27,8 +28,7 @@ static int finish_pack(const char *pack_tmp_name, const char *me)
dup2(pipe_fd[1], 1);
close(pipe_fd[0]);
close(pipe_fd[1]);
execlp("git-index-pack","git-index-pack",
"-o", idx, pack_tmp_name, NULL);
execl_git_cmd("index-pack", "-o", idx, pack_tmp_name, NULL);
error("cannot exec git-index-pack <%s> <%s>",
idx, pack_tmp_name);
exit(1);
......@@ -105,8 +105,7 @@ int receive_unpack_pack(int fd[2], const char *me, int quiet)
dup2(fd[0], 0);
close(fd[0]);
close(fd[1]);
execlp("git-unpack-objects", "git-unpack-objects",
quiet ? "-q" : NULL, NULL);
execl_git_cmd("unpack-objects", quiet ? "-q" : NULL, NULL);
die("git-unpack-objects exec failed");
}
close(fd[0]);
......
......@@ -10,6 +10,7 @@
#include <stdarg.h>
#include <sys/ioctl.h>
#include "git-compat-util.h"
#include "exec_cmd.h"
#ifndef PATH_MAX
# define PATH_MAX 4096
......@@ -233,14 +234,11 @@ int main(int argc, char **argv, char **envp)
{
char git_command[PATH_MAX + 1];
char wd[PATH_MAX + 1];
int i, len, show_help = 0;
char *exec_path = getenv("GIT_EXEC_PATH");
int i, show_help = 0;
const char *exec_path;
getcwd(wd, PATH_MAX);
if (!exec_path)
exec_path = GIT_EXEC_PATH;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
......@@ -256,10 +254,11 @@ int main(int argc, char **argv, char **envp)
if (!strncmp(arg, "exec-path", 9)) {
arg += 9;
if (*arg == '=')
if (*arg == '=') {
exec_path = arg + 1;
else {
puts(exec_path);
git_set_exec_path(exec_path);
} else {
puts(git_exec_path());
exit(0);
}
}
......@@ -275,42 +274,15 @@ int main(int argc, char **argv, char **envp)
if (i >= argc || show_help) {
if (i >= argc)
cmd_usage(exec_path, NULL);
cmd_usage(git_exec_path(), NULL);
show_man_page(argv[i]);
}
if (*exec_path != '/') {
if (!getcwd(git_command, sizeof(git_command))) {
fprintf(stderr,
"git: cannot determine current directory\n");
exit(1);
}
len = strlen(git_command);
/* Trivial cleanup */
while (!strncmp(exec_path, "./", 2)) {
exec_path += 2;
while (*exec_path == '/')
exec_path++;
}
snprintf(git_command + len, sizeof(git_command) - len,
"/%s", exec_path);
}
else
strcpy(git_command, exec_path);
len = strlen(git_command);
prepend_to_path(git_command, len);
len += snprintf(git_command + len, sizeof(git_command) - len,
"/git-%s", argv[i]);
if (sizeof(git_command) <= len) {
fprintf(stderr, "git: command name given is too long.\n");
exit(1);
}
exec_path = git_exec_path();
prepend_to_path(exec_path, strlen(exec_path));
/* execve() can only ever return if it fails */
execve(git_command, &argv[i], envp);
execv_git_cmd(argv + i);
if (errno == ENOENT)
cmd_usage(exec_path, "'%s' is not a git-command", argv[i]);
......
......@@ -6,7 +6,7 @@
static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
static const char unpacker[] = "git-unpack-objects";
static char *unpacker[] = { "unpack-objects", NULL };
static int report_status = 0;
......@@ -257,7 +257,7 @@ static void read_head_info(void)
static const char *unpack(int *error_code)
{
int code = run_command(unpacker, NULL);
int code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
*error_code = 0;
switch (code) {
......
#include "cache.h"
#include "run-command.h"
#include <sys/wait.h>
#include "exec_cmd.h"
int run_command_v_opt(int argc, char **argv, int flags)
{
......@@ -13,9 +14,13 @@ int run_command_v_opt(int argc, char **argv, int flags)
int fd = open("/dev/null", O_RDWR);
dup2(fd, 0);
dup2(fd, 1);
close(fd);
close(fd);
}
if (flags & RUN_GIT_CMD) {
execv_git_cmd(argv);
} else {
execvp(argv[0], (char *const*) argv);
}
execvp(argv[0], (char *const*) argv);
die("exec %s failed.", argv[0]);
}
for (;;) {
......
......@@ -12,7 +12,7 @@ enum {
};
#define RUN_COMMAND_NO_STDIO 1
#define RUN_GIT_CMD 2 /*If this is to be git sub-command */
int run_command_v_opt(int argc, char **argv, int opt);
int run_command_v(int argc, char **argv);
int run_command(const char *cmd, ...);
......
......@@ -3,6 +3,7 @@
#include "tag.h"
#include "refs.h"
#include "pkt-line.h"
#include "exec_cmd.h"
static const char send_pack_usage[] =
"git-send-pack [--all] [--exec=git-receive-pack] <remote> [<head>...]\n"
......@@ -26,11 +27,11 @@ static int is_zero_sha1(const unsigned char *sha1)
static void exec_pack_objects(void)
{
static char *args[] = {
"git-pack-objects",
"pack-objects",
"--stdout",
NULL
};
execvp("git-pack-objects", args);
execv_git_cmd(args);
die("git-pack-objects exec failed (%s)", strerror(errno));
}
......@@ -39,7 +40,7 @@ static void exec_rev_list(struct ref *refs)
static char *args[1000];
int i = 0;
args[i++] = "git-rev-list"; /* 0 */
args[i++] = "rev-list"; /* 0 */
args[i++] = "--objects"; /* 1 */
while (refs) {
char *buf = malloc(100);
......@@ -58,7 +59,7 @@ static void exec_rev_list(struct ref *refs)
refs = refs->next;
}
args[i] = NULL;
execvp("git-rev-list", args);
execv_git_cmd(args);
die("git-rev-list exec failed (%s)", strerror(errno));
}
......
#include "cache.h"
#include "quote.h"
#include "exec_cmd.h"
static int do_generic_cmd(const char *me, char *arg)
{
......@@ -7,12 +8,14 @@ static int do_generic_cmd(const char *me, char *arg)
if (!arg || !(arg = sq_dequote(arg)))
die("bad argument");
if (strncmp(me, "git-", 4))
die("bad command");
my_argv[0] = me;
my_argv[0] = me + 4;
my_argv[1] = arg;
my_argv[2] = NULL;
return execvp(me, (char**) my_argv);
return execv_git_cmd((char**) my_argv);
}
static struct commands {
......
......@@ -4,6 +4,7 @@
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "exec_cmd.h"
static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
......@@ -60,7 +61,7 @@ static void create_pack_file(void)
close(0);
close(fd[0]);
close(fd[1]);
*p++ = "git-rev-list";
*p++ = "rev-list";
*p++ = "--objects";
if (create_full_pack || MAX_NEEDS <= nr_needs)
*p++ = "--all";
......@@ -79,13 +80,13 @@ static void create_pack_file(void)
buf += 41;
}
*p++ = NULL;
execvp("git-rev-list", argv);
execv_git_cmd(argv);
die("git-upload-pack: unable to exec git-rev-list");
}
dup2(fd[0], 0);
close(fd[0]);
close(fd[1]);
execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
execl_git_cmd("pack-objects", "--stdout", NULL);
die("git-upload-pack: unable to exec git-pack-objects");
}
......
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