git/daemon.c

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25 KiB
C
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#include "cache.h"
#include "pkt-line.h"
#include "exec_cmd.h"
#include "run-command.h"
#include "strbuf.h"
#include <syslog.h>
#ifndef HOST_NAME_MAX
#define HOST_NAME_MAX 256
#endif
#ifndef NI_MAXSERV
#define NI_MAXSERV 32
#endif
static int log_syslog;
static int verbose;
static int reuseaddr;
static const char daemon_usage[] =
"git daemon [--verbose] [--syslog] [--export-all]\n"
" [--timeout=n] [--init-timeout=n] [--max-connections=n]\n"
" [--strict-paths] [--base-path=path] [--base-path-relaxed]\n"
" [--user-path | --user-path=path]\n"
" [--interpolated-path=path]\n"
" [--reuseaddr] [--detach] [--pid-file=file]\n"
" [--[enable|disable|allow-override|forbid-override]=service]\n"
" [--inetd | [--listen=host_or_ipaddr] [--port=n]\n"
" [--user=user [--group=group]]\n"
" [directory...]";
/* List of acceptable pathname prefixes */
static char **ok_paths;
static int strict_paths;
/* If this is set, git-daemon-export-ok is not required */
static int export_all_trees;
/* Take all paths relative to this one if non-NULL */
static char *base_path;
static char *interpolated_path;
static int base_path_relaxed;
/* Flag indicating client sent extra args. */
static int saw_extended_args;
/* If defined, ~user notation is allowed and the string is inserted
* after ~user/. E.g. a request to git://host/~alice/frotz would
* go to /home/alice/pub_git/frotz with --user-path=pub_git.
*/
static const char *user_path;
/* Timeout, and initial timeout */
static unsigned int timeout;
static unsigned int init_timeout;
static char *hostname;
static char *canon_hostname;
static char *ip_address;
static char *tcp_port;
static void logreport(int priority, const char *err, va_list params)
{
if (log_syslog) {
char buf[1024];
vsnprintf(buf, sizeof(buf), err, params);
syslog(priority, "%s", buf);
} else {
/*
* Since stderr is set to linebuffered mode, the
* logging of different processes will not overlap
*/
fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
vfprintf(stderr, err, params);
fputc('\n', stderr);
}
}
__attribute__((format (printf, 1, 2)))
static void logerror(const char *err, ...)
{
va_list params;
va_start(params, err);
logreport(LOG_ERR, err, params);
va_end(params);
}
__attribute__((format (printf, 1, 2)))
static void loginfo(const char *err, ...)
{
va_list params;
if (!verbose)
return;
va_start(params, err);
logreport(LOG_INFO, err, params);
va_end(params);
}
static void NORETURN daemon_die(const char *err, va_list params)
{
logreport(LOG_ERR, err, params);
exit(1);
}
static char *path_ok(char *directory)
{
static char rpath[PATH_MAX];
static char interp_path[PATH_MAX];
[PATCH] daemon.c and path.enter_repo(): revamp path validation. The whitelist of git-daemon is checked against return value from enter_repo(), and enter_repo() used to return the value obtained from getcwd() to avoid directory aliasing issues as discussed earier (mid October 2005). Unfortunately, it did not go well as we hoped. For example, /pub on a kernel.org public machine is a symlink to its real mountpoint, and it is understandable that the administrator does not want to adjust the whitelist every time /pub needs to point at a different partition for storage allcation or whatever reasons. Being able to keep using /pub/scm as the whitelist is a desirable property. So this version of enter_repo() reports what it used to chdir() and validate, but does not use getcwd() to canonicalize the directory name. When it sees a user relative path ~user/path, it internally resolves it to try chdir() there, but it still reports ~user/path (possibly after appending .git if allowed to do so, in which case it would report ~user/path.git). What this means is that if a whitelist wants to allow a user relative path, it needs to say "~" (for all users) or list user home directories like "~alice" "~bob". And no, you cannot say /home if the advertised way to access user home directories are ~alice,~bob, etc. The whole point of this is to avoid unnecessary aliasing issues. Anyway, because of this, daemon needs to do a bit more work to guard itself. Namely, it needs to make sure that the accessor does not try to exploit its leading path match rule by inserting /../ in the middle or hanging /.. at the end. I resurrected the belts and suspender paranoia code HPA did for this purpose. This check cannot be done in the enter_repo() unconditionally, because there are valid callers of enter_repo() that want to honor /../; authorized users coming over ssh to run send-pack and fetch-pack should be allowed to do so. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-03 09:45:57 +00:00
char *path;
char *dir;
dir = directory;
[PATCH] daemon.c and path.enter_repo(): revamp path validation. The whitelist of git-daemon is checked against return value from enter_repo(), and enter_repo() used to return the value obtained from getcwd() to avoid directory aliasing issues as discussed earier (mid October 2005). Unfortunately, it did not go well as we hoped. For example, /pub on a kernel.org public machine is a symlink to its real mountpoint, and it is understandable that the administrator does not want to adjust the whitelist every time /pub needs to point at a different partition for storage allcation or whatever reasons. Being able to keep using /pub/scm as the whitelist is a desirable property. So this version of enter_repo() reports what it used to chdir() and validate, but does not use getcwd() to canonicalize the directory name. When it sees a user relative path ~user/path, it internally resolves it to try chdir() there, but it still reports ~user/path (possibly after appending .git if allowed to do so, in which case it would report ~user/path.git). What this means is that if a whitelist wants to allow a user relative path, it needs to say "~" (for all users) or list user home directories like "~alice" "~bob". And no, you cannot say /home if the advertised way to access user home directories are ~alice,~bob, etc. The whole point of this is to avoid unnecessary aliasing issues. Anyway, because of this, daemon needs to do a bit more work to guard itself. Namely, it needs to make sure that the accessor does not try to exploit its leading path match rule by inserting /../ in the middle or hanging /.. at the end. I resurrected the belts and suspender paranoia code HPA did for this purpose. This check cannot be done in the enter_repo() unconditionally, because there are valid callers of enter_repo() that want to honor /../; authorized users coming over ssh to run send-pack and fetch-pack should be allowed to do so. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-03 09:45:57 +00:00
if (daemon_avoid_alias(dir)) {
[PATCH] daemon.c and path.enter_repo(): revamp path validation. The whitelist of git-daemon is checked against return value from enter_repo(), and enter_repo() used to return the value obtained from getcwd() to avoid directory aliasing issues as discussed earier (mid October 2005). Unfortunately, it did not go well as we hoped. For example, /pub on a kernel.org public machine is a symlink to its real mountpoint, and it is understandable that the administrator does not want to adjust the whitelist every time /pub needs to point at a different partition for storage allcation or whatever reasons. Being able to keep using /pub/scm as the whitelist is a desirable property. So this version of enter_repo() reports what it used to chdir() and validate, but does not use getcwd() to canonicalize the directory name. When it sees a user relative path ~user/path, it internally resolves it to try chdir() there, but it still reports ~user/path (possibly after appending .git if allowed to do so, in which case it would report ~user/path.git). What this means is that if a whitelist wants to allow a user relative path, it needs to say "~" (for all users) or list user home directories like "~alice" "~bob". And no, you cannot say /home if the advertised way to access user home directories are ~alice,~bob, etc. The whole point of this is to avoid unnecessary aliasing issues. Anyway, because of this, daemon needs to do a bit more work to guard itself. Namely, it needs to make sure that the accessor does not try to exploit its leading path match rule by inserting /../ in the middle or hanging /.. at the end. I resurrected the belts and suspender paranoia code HPA did for this purpose. This check cannot be done in the enter_repo() unconditionally, because there are valid callers of enter_repo() that want to honor /../; authorized users coming over ssh to run send-pack and fetch-pack should be allowed to do so. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-03 09:45:57 +00:00
logerror("'%s': aliased", dir);
return NULL;
}
if (*dir == '~') {
if (!user_path) {
logerror("'%s': User-path not allowed", dir);
return NULL;
}
if (*user_path) {
/* Got either "~alice" or "~alice/foo";
* rewrite them to "~alice/%s" or
* "~alice/%s/foo".
*/
int namlen, restlen = strlen(dir);
char *slash = strchr(dir, '/');
if (!slash)
slash = dir + restlen;
namlen = slash - dir;
restlen -= namlen;
loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
snprintf(rpath, PATH_MAX, "%.*s/%s%.*s",
namlen, dir, user_path, restlen, slash);
dir = rpath;
}
}
else if (interpolated_path && saw_extended_args) {
struct strbuf expanded_path = STRBUF_INIT;
struct strbuf_expand_dict_entry dict[] = {
{ "H", hostname },
{ "CH", canon_hostname },
{ "IP", ip_address },
{ "P", tcp_port },
{ "D", directory },
{ NULL }
};
if (*dir != '/') {
/* Allow only absolute */
logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
return NULL;
}
strbuf_expand(&expanded_path, interpolated_path,
strbuf_expand_dict_cb, &dict);
strlcpy(interp_path, expanded_path.buf, PATH_MAX);
strbuf_release(&expanded_path);
loginfo("Interpolated dir '%s'", interp_path);
dir = interp_path;
}
else if (base_path) {
if (*dir != '/') {
/* Allow only absolute */
logerror("'%s': Non-absolute path denied (base-path active)", dir);
return NULL;
}
snprintf(rpath, PATH_MAX, "%s%s", base_path, dir);
dir = rpath;
}
path = enter_repo(dir, strict_paths);
if (!path && base_path && base_path_relaxed) {
/*
* if we fail and base_path_relaxed is enabled, try without
* prefixing the base path
*/
dir = directory;
path = enter_repo(dir, strict_paths);
}
if (!path) {
logerror("'%s' does not appear to be a git repository", dir);
return NULL;
}
if ( ok_paths && *ok_paths ) {
char **pp;
int pathlen = strlen(path);
/* The validation is done on the paths after enter_repo
* appends optional {.git,.git/.git} and friends, but
[PATCH] daemon.c and path.enter_repo(): revamp path validation. The whitelist of git-daemon is checked against return value from enter_repo(), and enter_repo() used to return the value obtained from getcwd() to avoid directory aliasing issues as discussed earier (mid October 2005). Unfortunately, it did not go well as we hoped. For example, /pub on a kernel.org public machine is a symlink to its real mountpoint, and it is understandable that the administrator does not want to adjust the whitelist every time /pub needs to point at a different partition for storage allcation or whatever reasons. Being able to keep using /pub/scm as the whitelist is a desirable property. So this version of enter_repo() reports what it used to chdir() and validate, but does not use getcwd() to canonicalize the directory name. When it sees a user relative path ~user/path, it internally resolves it to try chdir() there, but it still reports ~user/path (possibly after appending .git if allowed to do so, in which case it would report ~user/path.git). What this means is that if a whitelist wants to allow a user relative path, it needs to say "~" (for all users) or list user home directories like "~alice" "~bob". And no, you cannot say /home if the advertised way to access user home directories are ~alice,~bob, etc. The whole point of this is to avoid unnecessary aliasing issues. Anyway, because of this, daemon needs to do a bit more work to guard itself. Namely, it needs to make sure that the accessor does not try to exploit its leading path match rule by inserting /../ in the middle or hanging /.. at the end. I resurrected the belts and suspender paranoia code HPA did for this purpose. This check cannot be done in the enter_repo() unconditionally, because there are valid callers of enter_repo() that want to honor /../; authorized users coming over ssh to run send-pack and fetch-pack should be allowed to do so. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-03 09:45:57 +00:00
* it does not use getcwd(). So if your /pub is
* a symlink to /mnt/pub, you can whitelist /pub and
* do not have to say /mnt/pub.
* Do not say /pub/.
*/
for ( pp = ok_paths ; *pp ; pp++ ) {
int len = strlen(*pp);
if (len <= pathlen &&
!memcmp(*pp, path, len) &&
(path[len] == '\0' ||
(!strict_paths && path[len] == '/')))
return path;
}
}
else {
/* be backwards compatible */
if (!strict_paths)
return path;
}
logerror("'%s': not in whitelist", path);
return NULL; /* Fallthrough. Deny by default */
}
typedef int (*daemon_service_fn)(void);
struct daemon_service {
const char *name;
const char *config_name;
daemon_service_fn fn;
int enabled;
int overridable;
};
static struct daemon_service *service_looking_at;
static int service_enabled;
static int git_daemon_config(const char *var, const char *value, void *cb)
{
if (!prefixcmp(var, "daemon.") &&
!strcmp(var + 7, service_looking_at->config_name)) {
service_enabled = git_config_bool(var, value);
return 0;
}
/* we are not interested in parsing any other configuration here */
return 0;
}
static int run_service(char *dir, struct daemon_service *service)
{
const char *path;
int enabled = service->enabled;
loginfo("Request %s for '%s'", service->name, dir);
if (!enabled && !service->overridable) {
logerror("'%s': service not enabled.", service->name);
errno = EACCES;
return -1;
}
if (!(path = path_ok(dir)))
return -1;
2005-09-27 15:49:40 +00:00
/*
* 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.
*
* path_ok() uses enter_repo() and does whitelist checking.
* We only need to make sure the repository is exported.
*/
if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
logerror("'%s': repository not exported.", path);
errno = EACCES;
return -1;
}
if (service->overridable) {
service_looking_at = service;
service_enabled = -1;
git_config(git_daemon_config, NULL);
if (0 <= service_enabled)
enabled = service_enabled;
}
if (!enabled) {
logerror("'%s': service not enabled for '%s'",
service->name, path);
errno = EACCES;
return -1;
}
/*
* We'll ignore SIGTERM from now on, we have a
* good client.
*/
signal(SIGTERM, SIG_IGN);
return service->fn();
}
static void copy_to_log(int fd)
{
struct strbuf line = STRBUF_INIT;
FILE *fp;
fp = fdopen(fd, "r");
if (fp == NULL) {
logerror("fdopen of error channel failed");
close(fd);
return;
}
while (strbuf_getline(&line, fp, '\n') != EOF) {
logerror("%s", line.buf);
strbuf_setlen(&line, 0);
}
strbuf_release(&line);
fclose(fp);
}
static int run_service_command(const char **argv)
{
struct child_process cld;
memset(&cld, 0, sizeof(cld));
cld.argv = argv;
cld.git_cmd = 1;
cld.err = -1;
if (start_command(&cld))
return -1;
close(0);
close(1);
copy_to_log(cld.err);
return finish_command(&cld);
}
static int upload_pack(void)
{
/* Timeout as string */
char timeout_buf[64];
const char *argv[] = { "upload-pack", "--strict", timeout_buf, ".", NULL };
snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
return run_service_command(argv);
}
static int upload_archive(void)
{
static const char *argv[] = { "upload-archive", ".", NULL };
return run_service_command(argv);
}
static int receive_pack(void)
{
static const char *argv[] = { "receive-pack", ".", NULL };
return run_service_command(argv);
}
static struct daemon_service daemon_service[] = {
{ "upload-archive", "uploadarch", upload_archive, 0, 1 },
{ "upload-pack", "uploadpack", upload_pack, 1, 1 },
{ "receive-pack", "receivepack", receive_pack, 0, 1 },
};
static void enable_service(const char *name, int ena)
{
int i;
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
if (!strcmp(daemon_service[i].name, name)) {
daemon_service[i].enabled = ena;
return;
}
}
die("No such service %s", name);
}
static void make_service_overridable(const char *name, int ena)
{
int i;
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
if (!strcmp(daemon_service[i].name, name)) {
daemon_service[i].overridable = ena;
return;
}
}
die("No such service %s", name);
}
static char *xstrdup_tolower(const char *str)
{
char *p, *dup = xstrdup(str);
for (p = dup; *p; p++)
*p = tolower(*p);
return dup;
}
static void parse_host_and_port(char *hostport, char **host,
char **port)
{
if (*hostport == '[') {
char *end;
end = strchr(hostport, ']');
if (!end)
die("Invalid request ('[' without ']')");
*end = '\0';
*host = hostport + 1;
if (!end[1])
*port = NULL;
else if (end[1] == ':')
*port = end + 2;
else
die("Garbage after end of host part");
} else {
*host = hostport;
*port = strrchr(hostport, ':');
if (*port) {
**port = '\0';
++*port;
}
}
}
/*
daemon: Strictly parse the "extra arg" part of the command Since 1.4.4.5 (49ba83fb67 "Add virtualization support to git-daemon") git daemon enters an infinite loop and never terminates if a client hides any extra arguments in the initial request line which is not exactly "\0host=blah\0". Since that change, a client must never insert additional extra arguments, or attempt to use any argument other than "host=", as any daemon will get stuck parsing the request line and will never complete the request. Since the client can't tell if the daemon is patched or not, it is not possible to know if additional extra args might actually be able to be safely requested. If we ever need to extend the git daemon protocol to support a new feature, we may have to do something like this to the exchange: # If both support git:// v2 # C: 000cgit://v2 S: 0010ok host user C: 0018host git.kernel.org C: 0027git-upload-pack /pub/linux-2.6.git S: ...git-upload-pack header... # If client supports git:// v2, server does not: # C: 000cgit://v2 S: <EOF> C: 003bgit-upload-pack /pub/linux-2.6.git\0host=git.kernel.org\0 S: ...git-upload-pack header... This requires the client to create two TCP connections to talk to an older git daemon, however all daemons since the introduction of daemon.c will safely reject the unknown "git://v2" command request, so the client can quite easily determine the server supports an older protocol. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-05 01:33:32 +00:00
* Read the host as supplied by the client connection.
*/
daemon: Strictly parse the "extra arg" part of the command Since 1.4.4.5 (49ba83fb67 "Add virtualization support to git-daemon") git daemon enters an infinite loop and never terminates if a client hides any extra arguments in the initial request line which is not exactly "\0host=blah\0". Since that change, a client must never insert additional extra arguments, or attempt to use any argument other than "host=", as any daemon will get stuck parsing the request line and will never complete the request. Since the client can't tell if the daemon is patched or not, it is not possible to know if additional extra args might actually be able to be safely requested. If we ever need to extend the git daemon protocol to support a new feature, we may have to do something like this to the exchange: # If both support git:// v2 # C: 000cgit://v2 S: 0010ok host user C: 0018host git.kernel.org C: 0027git-upload-pack /pub/linux-2.6.git S: ...git-upload-pack header... # If client supports git:// v2, server does not: # C: 000cgit://v2 S: <EOF> C: 003bgit-upload-pack /pub/linux-2.6.git\0host=git.kernel.org\0 S: ...git-upload-pack header... This requires the client to create two TCP connections to talk to an older git daemon, however all daemons since the introduction of daemon.c will safely reject the unknown "git://v2" command request, so the client can quite easily determine the server supports an older protocol. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-05 01:33:32 +00:00
static void parse_host_arg(char *extra_args, int buflen)
{
char *val;
int vallen;
char *end = extra_args + buflen;
daemon: Strictly parse the "extra arg" part of the command Since 1.4.4.5 (49ba83fb67 "Add virtualization support to git-daemon") git daemon enters an infinite loop and never terminates if a client hides any extra arguments in the initial request line which is not exactly "\0host=blah\0". Since that change, a client must never insert additional extra arguments, or attempt to use any argument other than "host=", as any daemon will get stuck parsing the request line and will never complete the request. Since the client can't tell if the daemon is patched or not, it is not possible to know if additional extra args might actually be able to be safely requested. If we ever need to extend the git daemon protocol to support a new feature, we may have to do something like this to the exchange: # If both support git:// v2 # C: 000cgit://v2 S: 0010ok host user C: 0018host git.kernel.org C: 0027git-upload-pack /pub/linux-2.6.git S: ...git-upload-pack header... # If client supports git:// v2, server does not: # C: 000cgit://v2 S: <EOF> C: 003bgit-upload-pack /pub/linux-2.6.git\0host=git.kernel.org\0 S: ...git-upload-pack header... This requires the client to create two TCP connections to talk to an older git daemon, however all daemons since the introduction of daemon.c will safely reject the unknown "git://v2" command request, so the client can quite easily determine the server supports an older protocol. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-05 01:33:32 +00:00
if (extra_args < end && *extra_args) {
saw_extended_args = 1;
if (strncasecmp("host=", extra_args, 5) == 0) {
val = extra_args + 5;
vallen = strlen(val) + 1;
if (*val) {
/* Split <host>:<port> at colon. */
char *host;
char *port;
parse_host_and_port(val, &host, &port);
if (port) {
free(tcp_port);
tcp_port = xstrdup(port);
}
free(hostname);
hostname = xstrdup_tolower(host);
}
/* On to the next one */
extra_args = val + vallen;
}
daemon: Strictly parse the "extra arg" part of the command Since 1.4.4.5 (49ba83fb67 "Add virtualization support to git-daemon") git daemon enters an infinite loop and never terminates if a client hides any extra arguments in the initial request line which is not exactly "\0host=blah\0". Since that change, a client must never insert additional extra arguments, or attempt to use any argument other than "host=", as any daemon will get stuck parsing the request line and will never complete the request. Since the client can't tell if the daemon is patched or not, it is not possible to know if additional extra args might actually be able to be safely requested. If we ever need to extend the git daemon protocol to support a new feature, we may have to do something like this to the exchange: # If both support git:// v2 # C: 000cgit://v2 S: 0010ok host user C: 0018host git.kernel.org C: 0027git-upload-pack /pub/linux-2.6.git S: ...git-upload-pack header... # If client supports git:// v2, server does not: # C: 000cgit://v2 S: <EOF> C: 003bgit-upload-pack /pub/linux-2.6.git\0host=git.kernel.org\0 S: ...git-upload-pack header... This requires the client to create two TCP connections to talk to an older git daemon, however all daemons since the introduction of daemon.c will safely reject the unknown "git://v2" command request, so the client can quite easily determine the server supports an older protocol. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-05 01:33:32 +00:00
if (extra_args < end && *extra_args)
die("Invalid request");
}
/*
* Locate canonical hostname and its IP address.
*/
if (hostname) {
#ifndef NO_IPV6
struct addrinfo hints;
struct addrinfo *ai;
int gai;
static char addrbuf[HOST_NAME_MAX + 1];
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_CANONNAME;
gai = getaddrinfo(hostname, NULL, &hints, &ai);
if (!gai) {
struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
inet_ntop(AF_INET, &sin_addr->sin_addr,
addrbuf, sizeof(addrbuf));
free(ip_address);
ip_address = xstrdup(addrbuf);
free(canon_hostname);
canon_hostname = xstrdup(ai->ai_canonname ?
ai->ai_canonname : ip_address);
freeaddrinfo(ai);
}
#else
struct hostent *hent;
struct sockaddr_in sa;
char **ap;
static char addrbuf[HOST_NAME_MAX + 1];
hent = gethostbyname(hostname);
ap = hent->h_addr_list;
memset(&sa, 0, sizeof sa);
sa.sin_family = hent->h_addrtype;
sa.sin_port = htons(0);
memcpy(&sa.sin_addr, *ap, hent->h_length);
inet_ntop(hent->h_addrtype, &sa.sin_addr,
addrbuf, sizeof(addrbuf));
free(canon_hostname);
canon_hostname = xstrdup(hent->h_name);
free(ip_address);
ip_address = xstrdup(addrbuf);
#endif
}
}
static int execute(struct sockaddr *addr)
{
static char line[1000];
int pktlen, len, i;
if (addr) {
char addrbuf[256] = "";
int port = -1;
if (addr->sa_family == AF_INET) {
struct sockaddr_in *sin_addr = (void *) addr;
inet_ntop(addr->sa_family, &sin_addr->sin_addr, addrbuf, sizeof(addrbuf));
port = ntohs(sin_addr->sin_port);
#ifndef NO_IPV6
} else if (addr && addr->sa_family == AF_INET6) {
struct sockaddr_in6 *sin6_addr = (void *) addr;
char *buf = addrbuf;
*buf++ = '['; *buf = '\0'; /* stpcpy() is cool */
inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(addrbuf) - 1);
strcat(buf, "]");
port = ntohs(sin6_addr->sin6_port);
#endif
}
loginfo("Connection from %s:%d", addrbuf, port);
setenv("REMOTE_ADDR", addrbuf, 1);
}
else {
unsetenv("REMOTE_ADDR");
}
alarm(init_timeout ? init_timeout : timeout);
pktlen = packet_read_line(0, line, sizeof(line));
alarm(0);
len = strlen(line);
if (pktlen != len)
loginfo("Extended attributes (%d bytes) exist <%.*s>",
(int) pktlen - len,
(int) pktlen - len, line + len + 1);
if (len && line[len-1] == '\n') {
line[--len] = 0;
pktlen--;
}
free(hostname);
free(canon_hostname);
free(ip_address);
free(tcp_port);
hostname = canon_hostname = ip_address = tcp_port = NULL;
if (len != pktlen)
daemon: Strictly parse the "extra arg" part of the command Since 1.4.4.5 (49ba83fb67 "Add virtualization support to git-daemon") git daemon enters an infinite loop and never terminates if a client hides any extra arguments in the initial request line which is not exactly "\0host=blah\0". Since that change, a client must never insert additional extra arguments, or attempt to use any argument other than "host=", as any daemon will get stuck parsing the request line and will never complete the request. Since the client can't tell if the daemon is patched or not, it is not possible to know if additional extra args might actually be able to be safely requested. If we ever need to extend the git daemon protocol to support a new feature, we may have to do something like this to the exchange: # If both support git:// v2 # C: 000cgit://v2 S: 0010ok host user C: 0018host git.kernel.org C: 0027git-upload-pack /pub/linux-2.6.git S: ...git-upload-pack header... # If client supports git:// v2, server does not: # C: 000cgit://v2 S: <EOF> C: 003bgit-upload-pack /pub/linux-2.6.git\0host=git.kernel.org\0 S: ...git-upload-pack header... This requires the client to create two TCP connections to talk to an older git daemon, however all daemons since the introduction of daemon.c will safely reject the unknown "git://v2" command request, so the client can quite easily determine the server supports an older protocol. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-05 01:33:32 +00:00
parse_host_arg(line + len + 1, pktlen - len - 1);
for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
struct daemon_service *s = &(daemon_service[i]);
int namelen = strlen(s->name);
if (!prefixcmp(line, "git-") &&
!strncmp(s->name, line + 4, namelen) &&
line[namelen + 4] == ' ') {
/*
* Note: The directory here is probably context sensitive,
* and might depend on the actual service being performed.
*/
return run_service(line + namelen + 5, s);
}
}
logerror("Protocol error: '%s'", line);
return -1;
}
static int addrcmp(const struct sockaddr_storage *s1,
const struct sockaddr_storage *s2)
{
const struct sockaddr *sa1 = (const struct sockaddr*) s1;
const struct sockaddr *sa2 = (const struct sockaddr*) s2;
if (sa1->sa_family != sa2->sa_family)
return sa1->sa_family - sa2->sa_family;
if (sa1->sa_family == AF_INET)
return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
&((struct sockaddr_in *)s2)->sin_addr,
sizeof(struct in_addr));
#ifndef NO_IPV6
if (sa1->sa_family == AF_INET6)
return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
&((struct sockaddr_in6 *)s2)->sin6_addr,
sizeof(struct in6_addr));
#endif
return 0;
}
static int max_connections = 32;
static unsigned int live_children;
static struct child {
struct child *next;
pid_t pid;
struct sockaddr_storage address;
} *firstborn;
static void add_child(pid_t pid, struct sockaddr *addr, int addrlen)
{
struct child *newborn, **cradle;
newborn = xcalloc(1, sizeof(*newborn));
live_children++;
newborn->pid = pid;
memcpy(&newborn->address, addr, addrlen);
for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
if (!addrcmp(&(*cradle)->address, &newborn->address))
break;
newborn->next = *cradle;
*cradle = newborn;
}
static void remove_child(pid_t pid)
{
struct child **cradle, *blanket;
for (cradle = &firstborn; (blanket = *cradle); cradle = &blanket->next)
if (blanket->pid == pid) {
*cradle = blanket->next;
live_children--;
free(blanket);
break;
}
}
/*
* This gets called if the number of connections grows
* past "max_connections".
*
* We kill the newest connection from a duplicate IP.
*/
static void kill_some_child(void)
{
const struct child *blanket, *next;
if (!(blanket = firstborn))
return;
for (; (next = blanket->next); blanket = next)
if (!addrcmp(&blanket->address, &next->address)) {
kill(blanket->pid, SIGTERM);
break;
}
}
static void check_dead_children(void)
{
int status;
pid_t pid;
while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
const char *dead = "";
remove_child(pid);
if (!WIFEXITED(status) || (WEXITSTATUS(status) > 0))
dead = " (with error)";
loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
}
}
static void handle(int incoming, struct sockaddr *addr, int addrlen)
{
pid_t pid;
if (max_connections && live_children >= max_connections) {
kill_some_child();
sleep(1); /* give it some time to die */
check_dead_children();
if (live_children >= max_connections) {
close(incoming);
logerror("Too many children, dropping connection");
return;
}
}
if ((pid = fork())) {
close(incoming);
if (pid < 0) {
logerror("Couldn't fork %s", strerror(errno));
return;
}
add_child(pid, addr, addrlen);
return;
}
dup2(incoming, 0);
dup2(incoming, 1);
close(incoming);
exit(execute(addr));
}
static void child_handler(int signo)
{
/*
* Otherwise empty handler because systemcalls will get interrupted
* upon signal receipt
* SysV needs the handler to be rearmed
*/
signal(SIGCHLD, child_handler);
}
static int set_reuse_addr(int sockfd)
{
int on = 1;
if (!reuseaddr)
return 0;
return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
&on, sizeof(on));
}
2005-09-29 00:26:44 +00:00
#ifndef NO_IPV6
static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
{
int socknum = 0, *socklist = NULL;
int maxfd = -1;
char pbuf[NI_MAXSERV];
2005-09-29 00:26:44 +00:00
struct addrinfo hints, *ai0, *ai;
int gai;
long flags;
sprintf(pbuf, "%d", listen_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(listen_addr, pbuf, &hints, &ai0);
if (gai)
die("getaddrinfo() failed: %s", gai_strerror(gai));
for (ai = ai0; ai; ai = ai->ai_next) {
int sockfd;
sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (sockfd < 0)
continue;
if (sockfd >= FD_SETSIZE) {
logerror("Socket descriptor too large");
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 (set_reuse_addr(sockfd)) {
close(sockfd);
continue;
}
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 */
}
flags = fcntl(sockfd, F_GETFD, 0);
if (flags >= 0)
fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
socklist = xrealloc(socklist, sizeof(int) * (socknum + 1));
socklist[socknum++] = sockfd;
if (maxfd < sockfd)
maxfd = sockfd;
}
freeaddrinfo(ai0);
2005-09-29 00:26:44 +00:00
*socklist_p = socklist;
return socknum;
}
#else /* NO_IPV6 */
static int socksetup(char *listen_addr, int listen_port, int **socklist_p)
2005-09-29 00:26:44 +00:00
{
struct sockaddr_in sin;
int sockfd;
long flags;
2005-09-29 00:26:44 +00:00
memset(&sin, 0, sizeof sin);
sin.sin_family = AF_INET;
sin.sin_port = htons(listen_port);
if (listen_addr) {
/* Well, host better be an IP address here. */
if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
return 0;
} else {
sin.sin_addr.s_addr = htonl(INADDR_ANY);
}
2005-09-29 00:26:44 +00:00
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
return 0;
if (set_reuse_addr(sockfd)) {
close(sockfd);
return 0;
}
2005-09-29 00:26:44 +00:00
if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
close(sockfd);
return 0;
}
if (listen(sockfd, 5) < 0) {
close(sockfd);
return 0;
}
flags = fcntl(sockfd, F_GETFD, 0);
if (flags >= 0)
fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
2005-09-30 17:47:50 +00:00
*socklist_p = xmalloc(sizeof(int));
2005-09-29 00:26:44 +00:00
**socklist_p = sockfd;
return 1;
2005-09-29 00:26:44 +00:00
}
#endif
static int service_loop(int socknum, int *socklist)
{
struct pollfd *pfd;
int i;
pfd = xcalloc(socknum, sizeof(struct pollfd));
2005-09-29 00:26:44 +00:00
for (i = 0; i < socknum; i++) {
pfd[i].fd = socklist[i];
pfd[i].events = POLLIN;
}
signal(SIGCHLD, child_handler);
for (;;) {
int i;
2005-09-29 00:26:44 +00:00
check_dead_children();
if (poll(pfd, socknum, -1) < 0) {
if (errno != EINTR) {
logerror("Poll failed, resuming: %s",
strerror(errno));
sleep(1);
}
continue;
}
for (i = 0; i < socknum; i++) {
2005-09-29 00:26:44 +00:00
if (pfd[i].revents & POLLIN) {
struct sockaddr_storage ss;
unsigned int sslen = sizeof(ss);
2005-09-29 00:26:44 +00:00
int incoming = accept(pfd[i].fd, (struct sockaddr *)&ss, &sslen);
if (incoming < 0) {
switch (errno) {
case EAGAIN:
case EINTR:
case ECONNABORTED:
continue;
default:
die_errno("accept returned");
}
}
handle(incoming, (struct sockaddr *)&ss, sslen);
}
}
}
}
/* if any standard file descriptor is missing open it to /dev/null */
static void sanitize_stdfds(void)
{
int fd = open("/dev/null", O_RDWR, 0);
while (fd != -1 && fd < 2)
fd = dup(fd);
if (fd == -1)
die_errno("open /dev/null or dup failed");
if (fd > 2)
close(fd);
}
static void daemonize(void)
{
switch (fork()) {
case 0:
break;
case -1:
die_errno("fork failed");
default:
exit(0);
}
if (setsid() == -1)
die_errno("setsid failed");
close(0);
close(1);
close(2);
sanitize_stdfds();
}
static void store_pid(const char *path)
{
FILE *f = fopen(path, "w");
if (!f)
die_errno("cannot open pid file '%s'", path);
if (fprintf(f, "%"PRIuMAX"\n", (uintmax_t) getpid()) < 0 || fclose(f) != 0)
die_errno("failed to write pid file '%s'", path);
}
static int serve(char *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
2005-09-29 00:26:44 +00:00
{
int socknum, *socklist;
2005-10-21 06:21:50 +00:00
socknum = socksetup(listen_addr, listen_port, &socklist);
2005-09-29 00:26:44 +00:00
if (socknum == 0)
die("unable to allocate any listen sockets on host %s port %u",
listen_addr, listen_port);
2005-10-21 06:21:50 +00:00
if (pass && gid &&
(initgroups(pass->pw_name, gid) || setgid (gid) ||
setuid(pass->pw_uid)))
die("cannot drop privileges");
2005-09-29 00:26:44 +00:00
return service_loop(socknum, socklist);
2005-10-21 06:21:50 +00:00
}
2005-09-29 00:26:44 +00:00
int main(int argc, char **argv)
{
int listen_port = 0;
char *listen_addr = NULL;
int inetd_mode = 0;
const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
int detach = 0;
struct passwd *pass = NULL;
struct group *group;
gid_t gid = 0;
int i;
git_extract_argv0_path(argv[0]);
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (!prefixcmp(arg, "--listen=")) {
listen_addr = xstrdup_tolower(arg + 9);
continue;
}
if (!prefixcmp(arg, "--port=")) {
char *end;
unsigned long n;
n = strtoul(arg+7, &end, 0);
if (arg[7] && !*end) {
listen_port = n;
continue;
}
}
if (!strcmp(arg, "--inetd")) {
inetd_mode = 1;
log_syslog = 1;
continue;
}
if (!strcmp(arg, "--verbose")) {
verbose = 1;
continue;
}
if (!strcmp(arg, "--syslog")) {
log_syslog = 1;
continue;
}
if (!strcmp(arg, "--export-all")) {
export_all_trees = 1;
continue;
}
if (!prefixcmp(arg, "--timeout=")) {
timeout = atoi(arg+10);
continue;
}
if (!prefixcmp(arg, "--init-timeout=")) {
init_timeout = atoi(arg+15);
continue;
}
if (!prefixcmp(arg, "--max-connections=")) {
max_connections = atoi(arg+18);
if (max_connections < 0)
max_connections = 0; /* unlimited */
continue;
}
if (!strcmp(arg, "--strict-paths")) {
strict_paths = 1;
continue;
}
if (!prefixcmp(arg, "--base-path=")) {
base_path = arg+12;
continue;
}
if (!strcmp(arg, "--base-path-relaxed")) {
base_path_relaxed = 1;
continue;
}
if (!prefixcmp(arg, "--interpolated-path=")) {
interpolated_path = arg+20;
continue;
}
if (!strcmp(arg, "--reuseaddr")) {
reuseaddr = 1;
continue;
}
if (!strcmp(arg, "--user-path")) {
user_path = "";
continue;
}
if (!prefixcmp(arg, "--user-path=")) {
user_path = arg + 12;
continue;
}
if (!prefixcmp(arg, "--pid-file=")) {
pid_file = arg + 11;
continue;
}
if (!strcmp(arg, "--detach")) {
detach = 1;
log_syslog = 1;
continue;
}
if (!prefixcmp(arg, "--user=")) {
user_name = arg + 7;
continue;
}
if (!prefixcmp(arg, "--group=")) {
group_name = arg + 8;
continue;
}
if (!prefixcmp(arg, "--enable=")) {
enable_service(arg + 9, 1);
continue;
}
if (!prefixcmp(arg, "--disable=")) {
enable_service(arg + 10, 0);
continue;
}
if (!prefixcmp(arg, "--allow-override=")) {
make_service_overridable(arg + 17, 1);
continue;
}
if (!prefixcmp(arg, "--forbid-override=")) {
make_service_overridable(arg + 18, 0);
continue;
}
if (!strcmp(arg, "--")) {
ok_paths = &argv[i+1];
break;
} else if (arg[0] != '-') {
ok_paths = &argv[i];
break;
}
usage(daemon_usage);
}
if (log_syslog) {
openlog("git-daemon", LOG_PID, LOG_DAEMON);
set_die_routine(daemon_die);
} else
/* avoid splitting a message in the middle */
setvbuf(stderr, NULL, _IOLBF, 0);
if (inetd_mode && (group_name || user_name))
die("--user and --group are incompatible with --inetd");
if (inetd_mode && (listen_port || listen_addr))
die("--listen= and --port= are incompatible with --inetd");
else if (listen_port == 0)
listen_port = DEFAULT_GIT_PORT;
if (group_name && !user_name)
die("--group supplied without --user");
if (user_name) {
pass = getpwnam(user_name);
if (!pass)
die("user not found - %s", user_name);
if (!group_name)
gid = pass->pw_gid;
else {
group = getgrnam(group_name);
if (!group)
die("group not found - %s", group_name);
gid = group->gr_gid;
}
}
if (strict_paths && (!ok_paths || !*ok_paths))
die("option --strict-paths requires a whitelist");
if (base_path && !is_directory(base_path))
die("base-path '%s' does not exist or is not a directory",
base_path);
if (inetd_mode) {
struct sockaddr_storage ss;
struct sockaddr *peer = (struct sockaddr *)&ss;
socklen_t slen = sizeof(ss);
if (!freopen("/dev/null", "w", stderr))
die_errno("failed to redirect stderr to /dev/null");
if (getpeername(0, peer, &slen))
peer = NULL;
return execute(peer);
}
if (detach) {
daemonize();
loginfo("Ready to rumble");
}
else
sanitize_stdfds();
if (pid_file)
store_pid(pid_file);
return serve(listen_addr, listen_port, pass, gid);
}