#include "builtin.h"
#include "transport.h"
#include "run-command.h"
/*
* URL syntax:
* 'command [arg1 [arg2 [...]]]' Invoke command with given arguments.
* Special characters:
* '% ': Literal space in argument.
* '%%': Literal percent sign.
* '%S': Name of service (git-upload-pack/git-upload-archive/
* git-receive-pack.
* '%s': Same as \s, but with possible git- prefix stripped.
* '%G': Only allowed as first 'character' of argument. Do not pass this
* Argument to command, instead send this as name of repository
* in in-line git://-style request (also activates sending this
* style of request).
* '%V': Only allowed as first 'character' of argument. Used in
* conjunction with '%G': Do not pass this argument to command,
* instead send this as vhost in git://-style request (note: does
* not activate sending git:// style request).
*/
static char *git_req;
static char *git_req_vhost;
static char *strip_escapes(const char *str, const char *service,
const char **next)
{
size_t rpos = 0;
int escape = 0;
char special = 0;
const char *service_noprefix = service;
struct strbuf ret = STRBUF_INIT;
skip_prefix(service_noprefix, "git-", &service_noprefix);
/* Pass the service to command. */
setenv("GIT_EXT_SERVICE", service, 1);
setenv("GIT_EXT_SERVICE_NOPREFIX", service_noprefix, 1);
/* Scan the length of argument. */
while (str[rpos] && (escape || str[rpos] != ' ')) {
if (escape) {
switch (str[rpos]) {
case ' ':
case '%':
case 's':
case 'S':
break;
case 'G':
case 'V':
special = str[rpos];
if (rpos == 1)
break;
/* Fall-through to error. */
default:
die("Bad remote-ext placeholder '%%%c'.",
str[rpos]);
}
escape = 0;
} else
escape = (str[rpos] == '%');
rpos++;
}
if (escape && !str[rpos])
die("remote-ext command has incomplete placeholder");
*next = str + rpos;
if (**next == ' ')
++*next; /* Skip over space */
/*
* Do the actual placeholder substitution. The string will be short
* enough not to overflow integers.
*/
rpos = special ? 2 : 0; /* Skip first 2 bytes in specials. */
escape = 0;
while (str[rpos] && (escape || str[rpos] != ' ')) {
if (escape) {
switch (str[rpos]) {
case ' ':
case '%':
strbuf_addch(&ret, str[rpos]);
break;
case 's':
strbuf_addstr(&ret, service_noprefix);
break;
case 'S':
strbuf_addstr(&ret, service);
break;
}
escape = 0;
} else
switch (str[rpos]) {
case '%':
escape = 1;
break;
default:
strbuf_addch(&ret, str[rpos]);
break;
}
rpos++;
}
switch (special) {
case 'G':
git_req = strbuf_detach(&ret, NULL);
return NULL;
case 'V':
git_req_vhost = strbuf_detach(&ret, NULL);
return NULL;
default:
return strbuf_detach(&ret, NULL);
}
}
/* Should be enough... */
#define MAXARGUMENTS 256
static const char **parse_argv(const char *arg, const char *service)
{
int arguments = 0;
int i;
const char **ret;
char *temparray[MAXARGUMENTS + 1];
while (*arg) {
char *expanded;
if (arguments == MAXARGUMENTS)
die("remote-ext command has too many arguments");
expanded = strip_escapes(arg, service, &arg);
if (expanded)
temparray[arguments++] = expanded;
}
ret = xmalloc((arguments + 1) * sizeof(char *));
for (i = 0; i < arguments; i++)
ret[i] = temparray[i];
ret[arguments] = NULL;
return ret;
}
static void send_git_request(int stdin_fd, const char *serv, const char *repo,
const char *vhost)
{
size_t bufferspace;
size_t wpos = 0;
char *buffer;
/*
* Request needs 12 bytes extra if there is vhost (xxxx \0host=\0) and
* 6 bytes extra (xxxx \0) if there is no vhost.
*/
if (vhost)
bufferspace = strlen(serv) + strlen(repo) + strlen(vhost) + 12;
else
bufferspace = strlen(serv) + strlen(repo) + 6;
if (bufferspace > 0xFFFF)
die("Request too large to send");
buffer = xmalloc(bufferspace);
/* Make the packet. */
wpos = sprintf(buffer, "%04x%s %s%c", (unsigned)bufferspace,
serv, repo, 0);
/* Add vhost if any. */
if (vhost)
sprintf(buffer + wpos, "host=%s%c", vhost, 0);
/* Send the request */
if (write_in_full(stdin_fd, buffer, bufferspace) < 0)
die_errno("Failed to send request");
free(buffer);
}
static int run_child(const char *arg, const char *service)
{
int r;
struct child_process child = CHILD_PROCESS_INIT;
child.in = -1;
child.out = -1;
child.err = 0;
child.argv = parse_argv(arg, service);
if (start_command(&child) < 0)
die("Can't run specified command");
if (git_req)
send_git_request(child.in, service, git_req, git_req_vhost);
r = bidirectional_transfer_loop(child.out, child.in);
if (!r)
r = finish_command(&child);
else
finish_command(&child);
return r;
}
#define MAXCOMMAND 4096
static int command_loop(const char *child)
{
char buffer[MAXCOMMAND];
while (1) {
size_t i;
if (!fgets(buffer, MAXCOMMAND - 1, stdin)) {
if (ferror(stdin))
die("Comammand input error");
exit(0);
}
/* Strip end of line characters. */
i = strlen(buffer);
while (i > 0 && isspace(buffer[i - 1]))
buffer[--i] = 0;
if (!strcmp(buffer, "capabilities")) {
printf("*connect\n\n");
fflush(stdout);
} else if (!strncmp(buffer, "connect ", 8)) {
printf("\n");
fflush(stdout);
return run_child(child, buffer + 8);
} else {
fprintf(stderr, "Bad command");
return 1;
}
}
}
int cmd_remote_ext(int argc, const char **argv, const char *prefix)
{
if (argc != 3)
die("Expected two arguments");
return command_loop(argv[2]);
}