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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: Michal Ostrowski <mostrows@watson.ibm.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
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Michal Ostrowski Junio C Hamano
Michal Ostrowski authored and Junio C Hamano committed Jan 11, 2006
1 parent c884dd9 commit 77cb17e940c806a4cc811bfd66187277b729a1e7
Showing with 176 additions and 62 deletions.
  1. +9 −4 Makefile
  2. +2 −1 daemon.c
  3. +117 −0 exec_cmd.c
  4. +10 −0 exec_cmd.h
  5. +3 −4 fetch-clone.c
  6. +11 −39 git.c
  7. +2 −2 receive-pack.c
  8. +7 −2 run-command.c
  9. +1 −1 run-command.h
  10. +5 −4 send-pack.c
  11. +5 −2 shell.c
  12. +4 −3 upload-pack.c
View
@@ -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))
View
@@ -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;
}
View
@@ -0,0 +1,117 @@
+#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);
+}
View
@@ -0,0 +1,10 @@
+#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_ */
View
@@ -1,4 +1,5 @@
#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]);
View
50 git.c
@@ -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]);
View
@@ -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) {
View
@@ -1,6 +1,7 @@
#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 (;;) {
View
@@ -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, ...);
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