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#include "cache.h"
#include "pkt-line.h"
#include <signal.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <netinet/in.h>
static const char daemon_usage[] = "git-daemon [--inetd | --port=n]";
/* We don't actually do anything about this yet */
static int max_connections = 10;
/*
* We count spawned/reaped separately, just to avoid any
* races when updating them from signals. The SIGCHLD handler
* will only update children_reaped, and the fork logic will
* only update children_spawned.
*/
static unsigned int children_spawned = 0;
static unsigned int children_reaped = 0;
static int upload(char *dir, int dirlen)
{
if (chdir(dir) < 0)
return -1;
chdir(".git");
/*
* Security on the cheap.
*
* We want a readable HEAD, usable "objects" directory, and
* a "git-daemon-export-ok" flag that says that the other side
* is ok with us doing this.
*/
if (access("git-daemon-export-ok", F_OK) ||
access("objects/00", X_OK) ||
access("HEAD", R_OK))
return -1;
/* git-upload-pack only ever reads stuff, so this is safe */
execlp("git-upload-pack", "git-upload-pack", ".", NULL);
return -1;
}
static int execute(void)
{
static char line[1000];
int len;
len = packet_read_line(0, line, sizeof(line));
if (len && line[len-1] == '\n')
line[--len] = 0;
if (!strncmp("git-upload-pack /", line, 17))
return upload(line + 16, len - 16);
fprintf(stderr, "got bad connection '%s'\n", line);
return -1;
}
static void handle(int incoming, struct sockaddr_in *addr, int addrlen)
{
pid_t pid = fork();
if (pid) {
int active;
close(incoming);
if (pid < 0)
return;
active = ++children_spawned - children_reaped;
if (active > max_connections) {
/*
* Fixme! This is where you'd have to do something to
* limit the number of children. Like killing off random
* ones, or at least the ones that haven't even gotten
* started yet.
*/
}
return;
}
dup2(incoming, 0);
dup2(incoming, 1);
close(incoming);
exit(execute());
}
static void child_handler(int signo)
{
for (;;) {
if (waitpid(-1, NULL, WNOHANG) > 0) {
children_reaped++;
continue;
}
break;
}
}
static int serve(int port)
{
int sockfd;
struct sockaddr_in addr;
signal(SIGCHLD, child_handler);
sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_IP);
if (sockfd < 0)
die("unable to open socket (%s)", strerror(errno));
memset(&addr, 0, sizeof(addr));
addr.sin_port = htons(port);
addr.sin_family = AF_INET;
if (bind(sockfd, (void *)&addr, sizeof(addr)) < 0)
die("unable to bind to port %d (%s)", port, strerror(errno));
if (listen(sockfd, 5) < 0)
die("unable to listen to port %d (%s)", port, strerror(errno));
for (;;) {
struct sockaddr_in in;
socklen_t addrlen = sizeof(in);
int incoming = accept(sockfd, (void *)&in, &addrlen);
if (incoming < 0) {
switch (errno) {
case EAGAIN:
case EINTR:
case ECONNABORTED:
continue;
default:
die("accept returned %s", strerror(errno));
}
}
handle(incoming, &in, addrlen);
}
}
int main(int argc, char **argv)
{
int port = DEFAULT_GIT_PORT;
int inetd_mode = 0;
int i;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (!strncmp(arg, "--port=", 7)) {
char *end;
unsigned long n;
n = strtoul(arg+7, &end, 0);
if (arg[7] && !*end) {
port = n;
continue;
}
}
if (!strcmp(arg, "--inetd")) {
inetd_mode = 1;
continue;
}
usage(daemon_usage);
}
if (inetd_mode)
return execute();
return serve(port);
}
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