From 77cb17e940c806a4cc811bfd66187277b729a1e7 Mon Sep 17 00:00:00 2001 From: Michal Ostrowski Date: Tue, 10 Jan 2006 21:12:17 -0500 Subject: [PATCH 1/1] 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 Signed-off-by: Junio C Hamano --- Makefile | 13 ++++-- daemon.c | 3 +- exec_cmd.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++ exec_cmd.h | 10 +++++ fetch-clone.c | 7 ++- git.c | 50 +++++---------------- receive-pack.c | 4 +- run-command.c | 9 +++- run-command.h | 2 +- send-pack.c | 9 ++-- shell.c | 7 ++- upload-pack.c | 7 +-- 12 files changed, 176 insertions(+), 62 deletions(-) create mode 100644 exec_cmd.c create mode 100644 exec_cmd.h diff --git a/Makefile b/Makefile index 3738811952..c48ae3bc65 100644 --- a/Makefile +++ b/Makefile @@ -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)) diff --git a/daemon.c b/daemon.c index 3bd14269d7..bb014fa9c2 100644 --- a/daemon.c +++ b/daemon.c @@ -9,6 +9,7 @@ #include #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; } diff --git a/exec_cmd.c b/exec_cmd.c new file mode 100644 index 0000000000..55af33bb7e --- /dev/null +++ b/exec_cmd.c @@ -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); +} diff --git a/exec_cmd.h b/exec_cmd.h new file mode 100644 index 0000000000..5150ee29f7 --- /dev/null +++ b/exec_cmd.h @@ -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_ */ diff --git a/fetch-clone.c b/fetch-clone.c index f46fe6ecbb..859f400941 100644 --- a/fetch-clone.c +++ b/fetch-clone.c @@ -1,4 +1,5 @@ #include "cache.h" +#include "exec_cmd.h" #include 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]); diff --git a/git.c b/git.c index 5e7da74b68..4616df6e62 100644 --- a/git.c +++ b/git.c @@ -10,6 +10,7 @@ #include #include #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]); diff --git a/receive-pack.c b/receive-pack.c index f847ec2b54..eae31e370d 100644 --- a/receive-pack.c +++ b/receive-pack.c @@ -6,7 +6,7 @@ static const char receive_pack_usage[] = "git-receive-pack "; -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) { diff --git a/run-command.c b/run-command.c index 8bf5922fc3..b3d287e97e 100644 --- a/run-command.c +++ b/run-command.c @@ -1,6 +1,7 @@ #include "cache.h" #include "run-command.h" #include +#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 (;;) { diff --git a/run-command.h b/run-command.h index 2469eeaefb..ef3ee053de 100644 --- a/run-command.h +++ b/run-command.h @@ -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, ...); diff --git a/send-pack.c b/send-pack.c index cd36193444..990be3f1a3 100644 --- a/send-pack.c +++ b/send-pack.c @@ -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] [...]\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)); } diff --git a/shell.c b/shell.c index cd316185e9..fc0c73cde7 100644 --- a/shell.c +++ b/shell.c @@ -1,5 +1,6 @@ #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 { diff --git a/upload-pack.c b/upload-pack.c index 1834b6ba8c..d1980556ca 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -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] "; @@ -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"); } -- 2.43.2