mirror of
https://github.com/git/git
synced 2024-10-30 04:01:21 +00:00
7fa090844f
This should work around the compilation problem Johannes Schindelin and others had on Mac OS/X. Quoting Linus: Any operating system where socklen_t is anything else than "int" is terminally broken. The people who introduced that typedef were confused, and I actually had to argue with them that it was fundamentally wrong: there is no other valid type than "int" that makes sense for it. Signed-off-by: Junio C Hamano <junkio@cox.net>
362 lines
7.6 KiB
C
362 lines
7.6 KiB
C
#include "cache.h"
|
|
#include "pkt-line.h"
|
|
#include <signal.h>
|
|
#include <sys/wait.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/time.h>
|
|
#include <netdb.h>
|
|
#include <netinet/in.h>
|
|
|
|
static const char daemon_usage[] = "git-daemon [--inetd | --port=n]";
|
|
|
|
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;
|
|
|
|
/*
|
|
* We'll ignore SIGTERM from now on, we have a
|
|
* good client.
|
|
*/
|
|
signal(SIGTERM, SIG_IGN);
|
|
|
|
/* 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;
|
|
}
|
|
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* MAX_CHILDREN should be a power-of-two to make the modulus
|
|
* operation cheap. It should also be at least twice
|
|
* the maximum number of connections we will ever allow.
|
|
*/
|
|
#define MAX_CHILDREN 128
|
|
|
|
static int max_connections = 25;
|
|
|
|
/* These are updated by the signal handler */
|
|
static volatile unsigned int children_reaped = 0;
|
|
static pid_t dead_child[MAX_CHILDREN];
|
|
|
|
/* These are updated by the main loop */
|
|
static unsigned int children_spawned = 0;
|
|
static unsigned int children_deleted = 0;
|
|
|
|
static struct child {
|
|
pid_t pid;
|
|
int addrlen;
|
|
struct sockaddr_storage address;
|
|
} live_child[MAX_CHILDREN];
|
|
|
|
static void add_child(int idx, pid_t pid, struct sockaddr *addr, int addrlen)
|
|
{
|
|
live_child[idx].pid = pid;
|
|
live_child[idx].addrlen = addrlen;
|
|
memcpy(&live_child[idx].address, addr, addrlen);
|
|
}
|
|
|
|
/*
|
|
* Walk from "deleted" to "spawned", and remove child "pid".
|
|
*
|
|
* We move everything up by one, since the new "deleted" will
|
|
* be one higher.
|
|
*/
|
|
static void remove_child(pid_t pid, unsigned deleted, unsigned spawned)
|
|
{
|
|
struct child n;
|
|
|
|
deleted %= MAX_CHILDREN;
|
|
spawned %= MAX_CHILDREN;
|
|
if (live_child[deleted].pid == pid) {
|
|
live_child[deleted].pid = -1;
|
|
return;
|
|
}
|
|
n = live_child[deleted];
|
|
for (;;) {
|
|
struct child m;
|
|
deleted = (deleted + 1) % MAX_CHILDREN;
|
|
if (deleted == spawned)
|
|
die("could not find dead child %d\n", pid);
|
|
m = live_child[deleted];
|
|
live_child[deleted] = n;
|
|
if (m.pid == pid)
|
|
return;
|
|
n = m;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This gets called if the number of connections grows
|
|
* past "max_connections".
|
|
*
|
|
* We _should_ start off by searching for connections
|
|
* from the same IP, and if there is some address wth
|
|
* multiple connections, we should kill that first.
|
|
*
|
|
* As it is, we just "randomly" kill 25% of the connections,
|
|
* and our pseudo-random generator sucks too. I have no
|
|
* shame.
|
|
*
|
|
* Really, this is just a place-holder for a _real_ algorithm.
|
|
*/
|
|
static void kill_some_children(int signo, unsigned start, unsigned stop)
|
|
{
|
|
start %= MAX_CHILDREN;
|
|
stop %= MAX_CHILDREN;
|
|
while (start != stop) {
|
|
if (!(start & 3))
|
|
kill(live_child[start].pid, signo);
|
|
start = (start + 1) % MAX_CHILDREN;
|
|
}
|
|
}
|
|
|
|
static void check_max_connections(void)
|
|
{
|
|
for (;;) {
|
|
int active;
|
|
unsigned spawned, reaped, deleted;
|
|
|
|
spawned = children_spawned;
|
|
reaped = children_reaped;
|
|
deleted = children_deleted;
|
|
|
|
while (deleted < reaped) {
|
|
pid_t pid = dead_child[deleted % MAX_CHILDREN];
|
|
remove_child(pid, deleted, spawned);
|
|
deleted++;
|
|
}
|
|
children_deleted = deleted;
|
|
|
|
active = spawned - deleted;
|
|
if (active <= max_connections)
|
|
break;
|
|
|
|
/* Kill some unstarted connections with SIGTERM */
|
|
kill_some_children(SIGTERM, deleted, spawned);
|
|
if (active <= max_connections << 1)
|
|
break;
|
|
|
|
/* If the SIGTERM thing isn't helping use SIGKILL */
|
|
kill_some_children(SIGKILL, deleted, spawned);
|
|
sleep(1);
|
|
}
|
|
}
|
|
|
|
static void handle(int incoming, struct sockaddr *addr, int addrlen)
|
|
{
|
|
pid_t pid = fork();
|
|
|
|
if (pid) {
|
|
unsigned idx;
|
|
|
|
close(incoming);
|
|
if (pid < 0)
|
|
return;
|
|
|
|
idx = children_spawned % MAX_CHILDREN;
|
|
children_spawned++;
|
|
add_child(idx, pid, addr, addrlen);
|
|
|
|
check_max_connections();
|
|
return;
|
|
}
|
|
|
|
dup2(incoming, 0);
|
|
dup2(incoming, 1);
|
|
close(incoming);
|
|
exit(execute());
|
|
}
|
|
|
|
static void child_handler(int signo)
|
|
{
|
|
for (;;) {
|
|
pid_t pid = waitpid(-1, NULL, WNOHANG);
|
|
|
|
if (pid > 0) {
|
|
unsigned reaped = children_reaped;
|
|
dead_child[reaped % MAX_CHILDREN] = pid;
|
|
children_reaped = reaped + 1;
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int serve(int port)
|
|
{
|
|
struct addrinfo hints, *ai0, *ai;
|
|
int gai;
|
|
int socknum = 0, *socklist = NULL;
|
|
int maxfd = -1;
|
|
fd_set fds_init, fds;
|
|
char pbuf[NI_MAXSERV];
|
|
|
|
signal(SIGCHLD, child_handler);
|
|
|
|
sprintf(pbuf, "%d", port);
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = AF_UNSPEC;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
hints.ai_protocol = IPPROTO_TCP;
|
|
hints.ai_flags = AI_PASSIVE;
|
|
|
|
gai = getaddrinfo(NULL, pbuf, &hints, &ai0);
|
|
if (gai)
|
|
die("getaddrinfo() failed: %s\n", gai_strerror(gai));
|
|
|
|
FD_ZERO(&fds_init);
|
|
|
|
for (ai = ai0; ai; ai = ai->ai_next) {
|
|
int sockfd;
|
|
int *newlist;
|
|
|
|
sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
|
|
if (sockfd < 0)
|
|
continue;
|
|
if (sockfd >= FD_SETSIZE) {
|
|
error("too large socket descriptor.");
|
|
close(sockfd);
|
|
continue;
|
|
}
|
|
|
|
#ifdef IPV6_V6ONLY
|
|
if (ai->ai_family == AF_INET6) {
|
|
int on = 1;
|
|
setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
|
|
&on, sizeof(on));
|
|
/* Note: error is not fatal */
|
|
}
|
|
#endif
|
|
|
|
if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
|
|
close(sockfd);
|
|
continue; /* not fatal */
|
|
}
|
|
if (listen(sockfd, 5) < 0) {
|
|
close(sockfd);
|
|
continue; /* not fatal */
|
|
}
|
|
|
|
newlist = realloc(socklist, sizeof(int) * (socknum + 1));
|
|
if (!newlist)
|
|
die("memory allocation failed: %s", strerror(errno));
|
|
|
|
socklist = newlist;
|
|
socklist[socknum++] = sockfd;
|
|
|
|
FD_SET(sockfd, &fds_init);
|
|
if (maxfd < sockfd)
|
|
maxfd = sockfd;
|
|
}
|
|
|
|
freeaddrinfo(ai0);
|
|
|
|
if (socknum == 0)
|
|
die("unable to allocate any listen sockets on port %u", port);
|
|
|
|
for (;;) {
|
|
int i;
|
|
fds = fds_init;
|
|
|
|
if (select(maxfd + 1, &fds, NULL, NULL, NULL) < 0) {
|
|
if (errno != EINTR) {
|
|
error("select failed, resuming: %s",
|
|
strerror(errno));
|
|
sleep(1);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
for (i = 0; i < socknum; i++) {
|
|
int sockfd = socklist[i];
|
|
|
|
if (FD_ISSET(sockfd, &fds)) {
|
|
struct sockaddr_storage ss;
|
|
int sslen = sizeof(ss);
|
|
int incoming = accept(sockfd, (struct sockaddr *)&ss, &sslen);
|
|
if (incoming < 0) {
|
|
switch (errno) {
|
|
case EAGAIN:
|
|
case EINTR:
|
|
case ECONNABORTED:
|
|
continue;
|
|
default:
|
|
die("accept returned %s", strerror(errno));
|
|
}
|
|
}
|
|
handle(incoming, (struct sockaddr *)&ss, sslen);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
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) {
|
|
fclose(stderr); //FIXME: workaround
|
|
return execute();
|
|
}
|
|
|
|
return serve(port);
|
|
}
|