Revision 3ebbd00cf3c5a7c6f90e2fed8adaf0c5145fb4ac authored by Jim Hill on 31 May 2015, 18:16:45 UTC, committed by Junio C Hamano on 10 August 2015, 19:51:13 UTC
The loop in strbuf_read() uses xread() repeatedly while extending the strbuf until the call returns zero. If the buffer is sufficiently large to begin with, this results in xread() returning the remainder of the file to the end (returning non-zero), the loop extending the strbuf, and then making another call to xread() to have it return zero. By using read_in_full(), we can tell when the read reached the end of file: when it returns less than was requested, it's eof. This way we can avoid an extra iteration that allocates an extra 8kB that is never used. Signed-off-by: Jim Hill <gjthill@gmail.com> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 282616c
shell.c
#include "cache.h"
#include "quote.h"
#include "exec_cmd.h"
#include "strbuf.h"
#include "run-command.h"
#define COMMAND_DIR "git-shell-commands"
#define HELP_COMMAND COMMAND_DIR "/help"
#define NOLOGIN_COMMAND COMMAND_DIR "/no-interactive-login"
static int do_generic_cmd(const char *me, char *arg)
{
const char *my_argv[4];
setup_path();
if (!arg || !(arg = sq_dequote(arg)))
die("bad argument");
if (!starts_with(me, "git-"))
die("bad command");
my_argv[0] = me + 4;
my_argv[1] = arg;
my_argv[2] = NULL;
return execv_git_cmd(my_argv);
}
static int do_cvs_cmd(const char *me, char *arg)
{
const char *cvsserver_argv[3] = {
"cvsserver", "server", NULL
};
if (!arg || strcmp(arg, "server"))
die("git-cvsserver only handles server: %s", arg);
setup_path();
return execv_git_cmd(cvsserver_argv);
}
static int is_valid_cmd_name(const char *cmd)
{
/* Test command contains no . or / characters */
return cmd[strcspn(cmd, "./")] == '\0';
}
static char *make_cmd(const char *prog)
{
char *prefix = xmalloc((strlen(prog) + strlen(COMMAND_DIR) + 2));
strcpy(prefix, COMMAND_DIR);
strcat(prefix, "/");
strcat(prefix, prog);
return prefix;
}
static void cd_to_homedir(void)
{
const char *home = getenv("HOME");
if (!home)
die("could not determine user's home directory; HOME is unset");
if (chdir(home) == -1)
die("could not chdir to user's home directory");
}
static void run_shell(void)
{
int done = 0;
static const char *help_argv[] = { HELP_COMMAND, NULL };
if (!access(NOLOGIN_COMMAND, F_OK)) {
/* Interactive login disabled. */
const char *argv[] = { NOLOGIN_COMMAND, NULL };
int status;
status = run_command_v_opt(argv, 0);
if (status < 0)
exit(127);
exit(status);
}
/* Print help if enabled */
run_command_v_opt(help_argv, RUN_SILENT_EXEC_FAILURE);
do {
struct strbuf line = STRBUF_INIT;
const char *prog;
char *full_cmd;
char *rawargs;
char *split_args;
const char **argv;
int code;
int count;
fprintf(stderr, "git> ");
if (strbuf_getline(&line, stdin, '\n') == EOF) {
fprintf(stderr, "\n");
strbuf_release(&line);
break;
}
strbuf_trim(&line);
rawargs = strbuf_detach(&line, NULL);
split_args = xstrdup(rawargs);
count = split_cmdline(split_args, &argv);
if (count < 0) {
fprintf(stderr, "invalid command format '%s': %s\n", rawargs,
split_cmdline_strerror(count));
free(split_args);
free(rawargs);
continue;
}
prog = argv[0];
if (!strcmp(prog, "")) {
} else if (!strcmp(prog, "quit") || !strcmp(prog, "logout") ||
!strcmp(prog, "exit") || !strcmp(prog, "bye")) {
done = 1;
} else if (is_valid_cmd_name(prog)) {
full_cmd = make_cmd(prog);
argv[0] = full_cmd;
code = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE);
if (code == -1 && errno == ENOENT) {
fprintf(stderr, "unrecognized command '%s'\n", prog);
}
free(full_cmd);
} else {
fprintf(stderr, "invalid command format '%s'\n", prog);
}
free(argv);
free(rawargs);
} while (!done);
}
static struct commands {
const char *name;
int (*exec)(const char *me, char *arg);
} cmd_list[] = {
{ "git-receive-pack", do_generic_cmd },
{ "git-upload-pack", do_generic_cmd },
{ "git-upload-archive", do_generic_cmd },
{ "cvs", do_cvs_cmd },
{ NULL },
};
int main(int argc, char **argv)
{
char *prog;
const char **user_argv;
struct commands *cmd;
int count;
git_setup_gettext();
git_extract_argv0_path(argv[0]);
/*
* Always open file descriptors 0/1/2 to avoid clobbering files
* in die(). It also avoids messing up when the pipes are dup'ed
* onto stdin/stdout/stderr in the child processes we spawn.
*/
sanitize_stdfds();
/*
* Special hack to pretend to be a CVS server
*/
if (argc == 2 && !strcmp(argv[1], "cvs server")) {
argv--;
} else if (argc == 1) {
/* Allow the user to run an interactive shell */
cd_to_homedir();
if (access(COMMAND_DIR, R_OK | X_OK) == -1) {
die("Interactive git shell is not enabled.\n"
"hint: ~/" COMMAND_DIR " should exist "
"and have read and execute access.");
}
run_shell();
exit(0);
} else if (argc != 3 || strcmp(argv[1], "-c")) {
/*
* We do not accept any other modes except "-c" followed by
* "cmd arg", where "cmd" is a very limited subset of git
* commands or a command in the COMMAND_DIR
*/
die("Run with no arguments or with -c cmd");
}
prog = xstrdup(argv[2]);
if (!strncmp(prog, "git", 3) && isspace(prog[3]))
/* Accept "git foo" as if the caller said "git-foo". */
prog[3] = '-';
for (cmd = cmd_list ; cmd->name ; cmd++) {
int len = strlen(cmd->name);
char *arg;
if (strncmp(cmd->name, prog, len))
continue;
arg = NULL;
switch (prog[len]) {
case '\0':
arg = NULL;
break;
case ' ':
arg = prog + len + 1;
break;
default:
continue;
}
exit(cmd->exec(cmd->name, arg));
}
cd_to_homedir();
count = split_cmdline(prog, &user_argv);
if (count >= 0) {
if (is_valid_cmd_name(user_argv[0])) {
prog = make_cmd(user_argv[0]);
user_argv[0] = prog;
execv(user_argv[0], (char *const *) user_argv);
}
free(prog);
free(user_argv);
die("unrecognized command '%s'", argv[2]);
} else {
free(prog);
die("invalid command format '%s': %s", argv[2],
split_cmdline_strerror(count));
}
}
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