[PATCH] daemon: --access-hook option
The --access-hook option to "git daemon" specifies an external command to be run every time a client connects, with - service name (e.g. "upload-pack", etc.), - path to the repository, - hostname (%H), - canonical hostname (%CH), - ip address (%IP), - tcp port (%P) as its command line arguments. The external command can decide to decline the service by exiting with a non-zero status (or to allow it by exiting with a zero status). It can also look at the $REMOTE_ADDR and $REMOTE_PORT environment variables to learn about the requestor when making this decision. The external command can optionally write a single line to its standard output to be sent to the requestor as an error message when it declines the service. Signed-off-by: Junio C Hamano --- * This time, minimally tested, with a documentation update. Documentation/git-daemon.txt | 16 + daemon.c | 77 2 files changed, 93 insertions(+) diff --git a/Documentation/git-daemon.txt b/Documentation/git-daemon.txt index 31b28fc..c3ba4d7 100644 --- a/Documentation/git-daemon.txt +++ b/Documentation/git-daemon.txt @@ -16,6 +16,7 @@ SYNOPSIS [--reuseaddr] [--detach] [--pid-file=] [--enable=] [--disable=] [--allow-override=] [--forbid-override=] +[--access-hook=] [--inetd | [--listen=] [--port=] [--user= [--group=]] [...] @@ -171,6 +172,21 @@ the facility of inet daemon to achieve the same before spawning errors are not enabled, all errors report "access denied" to the client. The default is --no-informative-errors. +--access-hook=:: + Every time a client connects, first run an external command + specified by the with service name (e.g. "upload-pack"), + path to the repository, hostname (%H), canonical hostname + (%CH), ip address (%IP), and tcp port (%P) as its command line + arguments. The external command can decide to decline the + service by exiting with a non-zero status (or to allow it by + exiting with a zero status). It can also look at the $REMOTE_ADDR + and $REMOTE_PORT environment variables to learn about the + requestor when making this decision. ++ +The external command can optionally write a single line to its +standard output to be sent to the requestor as an error message when +it declines the service. + :: A directory to add to the whitelist of allowed directories. Unless --strict-paths is specified this will also include subdirectories diff --git a/daemon.c b/daemon.c index ab21e66..4602b46 100644 --- a/daemon.c +++ b/daemon.c @@ -30,6 +30,7 @@ static const char daemon_usage[] = " [--interpolated-path=]\n" " [--reuseaddr] [--pid-file=]\n" " [--(enable|disable|allow-override|forbid-override)=]\n" +" [--access-hook=]\n" " [--inetd | [--listen=] [--port=]\n" " [--detach] [--user= [--group=]]\n" " [...]"; @@ -256,6 +257,71 @@ static int daemon_error(const char *dir, const char *msg) return -1; } +static char *access_hook; + +static int run_access_hook(struct daemon_service *service, const char *dir, const char *path) +{ + struct child_process child; + struct strbuf buf = STRBUF_INIT; + const char *argv[8]; + const char **arg = argv; + char *eol; + int seen_errors = 0; + +#define STRARG(x) ((x) ? (x) : "") + *arg++ = access_hook; + *arg++ = service->name; + *arg++ = path; + *arg++ = STRARG(hostname); + *arg++ = STRARG(canon_hostname); + *arg++ = STRARG(ip_address); + *arg++ = STRARG(tcp_port); + *arg = NULL; +#undef STRARG + + memset(&child, 0, sizeof(child)); + child.use_shell = 1; + child.argv = argv; + child.no_stdin = 1; + child.no_stderr = 1; + child.out = -1; + if (start_command(&child)) { + logerror("daemon access hook '%s' failed to start", +access_hook); + goto error_return; + } + if (strbuf_read(&buf, child.out, 0) < 0) { + logerror("failed to read from pipe to daemon access hook '%s'", +access_hook); + strbuf_reset(&buf); + seen_errors = 1; + } + if (close(child.out) < 0) { + logerror("failed to close pipe to daemon access hook '%s'", +access_hook); + seen_errors = 1; + } + if (finish_command(&child)) + seen_errors = 1; + + if (!seen_errors) { + strbuf_release(&buf); + return 0; + } + +error_return: + strbuf_ltrim(&buf); + if (!buf.len) + strbuf_addstr(&buf, "service rejected"); + eol = strchr(buf.buf, '\n'); + if (eol) + *eol = '\0'; + errno = EAC
Re: [PATCH] daemon: --access-hook option
On Tue, Aug 14, 2012 at 10:12 PM, Junio C Hamano wrote: > The --access-hook option to "git daemon" specifies an external > command to be run every time a client connects, with > > - service name (e.g. "upload-pack", etc.), > - path to the repository, > - hostname (%H), > - canonical hostname (%CH), > - ip address (%IP), > - tcp port (%P) > > as its command line arguments. The external command can decide to > decline the service by exiting with a non-zero status (or to allow it > by exiting with a zero status). It can also look at the $REMOTE_ADDR > and $REMOTE_PORT environment variables to learn about the requestor > when making this decision. > > The external command can optionally write a single line to its > standard output to be sent to the requestor as an error message when > it declines the service. > > Signed-off-by: Junio C Hamano Thanks Junio, this looks like the best approach. Acked-by: Shawn O. Pearce -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] daemon: --access-hook option
Right, this approach of having ACL using the --access-hook option looks much better. At least you got inspired this could be useful for somebody ;-) Michal On 08/15/2012 07:12 AM, Junio C Hamano wrote: > The --access-hook option to "git daemon" specifies an external > command to be run every time a client connects, with > > - service name (e.g. "upload-pack", etc.), > - path to the repository, > - hostname (%H), > - canonical hostname (%CH), > - ip address (%IP), > - tcp port (%P) > > as its command line arguments. The external command can decide to > decline the service by exiting with a non-zero status (or to allow it > by exiting with a zero status). It can also look at the $REMOTE_ADDR > and $REMOTE_PORT environment variables to learn about the requestor > when making this decision. > > The external command can optionally write a single line to its > standard output to be sent to the requestor as an error message when > it declines the service. > > Signed-off-by: Junio C Hamano > --- > > * This time, minimally tested, with a documentation update. > > Documentation/git-daemon.txt | 16 + > daemon.c | 77 > > 2 files changed, 93 insertions(+) > > diff --git a/Documentation/git-daemon.txt b/Documentation/git-daemon.txt > index 31b28fc..c3ba4d7 100644 > --- a/Documentation/git-daemon.txt > +++ b/Documentation/git-daemon.txt > @@ -16,6 +16,7 @@ SYNOPSIS >[--reuseaddr] [--detach] [--pid-file=] >[--enable=] [--disable=] >[--allow-override=] [--forbid-override=] > + [--access-hook=] >[--inetd | [--listen=] [--port=] [--user= > [--group=]] >[...] > > @@ -171,6 +172,21 @@ the facility of inet daemon to achieve the same before > spawning > errors are not enabled, all errors report "access denied" to the > client. The default is --no-informative-errors. > > +--access-hook=:: > + Every time a client connects, first run an external command > + specified by the with service name (e.g. "upload-pack"), > + path to the repository, hostname (%H), canonical hostname > + (%CH), ip address (%IP), and tcp port (%P) as its command line > + arguments. The external command can decide to decline the > + service by exiting with a non-zero status (or to allow it by > + exiting with a zero status). It can also look at the $REMOTE_ADDR > + and $REMOTE_PORT environment variables to learn about the > + requestor when making this decision. > ++ > +The external command can optionally write a single line to its > +standard output to be sent to the requestor as an error message when > +it declines the service. > + > :: > A directory to add to the whitelist of allowed directories. Unless > --strict-paths is specified this will also include subdirectories > diff --git a/daemon.c b/daemon.c > index ab21e66..4602b46 100644 > --- a/daemon.c > +++ b/daemon.c > @@ -30,6 +30,7 @@ static const char daemon_usage[] = > " [--interpolated-path=]\n" > " [--reuseaddr] [--pid-file=]\n" > " [--(enable|disable|allow-override|forbid-override)=]\n" > +" [--access-hook=]\n" > " [--inetd | [--listen=] [--port=]\n" > " [--detach] [--user= [--group=]]\n" > " [...]"; > @@ -256,6 +257,71 @@ static int daemon_error(const char *dir, const char *msg) > return -1; > } > > +static char *access_hook; > + > +static int run_access_hook(struct daemon_service *service, const char *dir, > const char *path) > +{ > + struct child_process child; > + struct strbuf buf = STRBUF_INIT; > + const char *argv[8]; > + const char **arg = argv; > + char *eol; > + int seen_errors = 0; > + > +#define STRARG(x) ((x) ? (x) : "") > + *arg++ = access_hook; > + *arg++ = service->name; > + *arg++ = path; > + *arg++ = STRARG(hostname); > + *arg++ = STRARG(canon_hostname); > + *arg++ = STRARG(ip_address); > + *arg++ = STRARG(tcp_port); > + *arg = NULL; > +#undef STRARG > + > + memset(&child, 0, sizeof(child)); > + child.use_shell = 1; > + child.argv = argv; > + child.no_stdin = 1; > + child.no_stderr = 1; > + child.out = -1; > + if (start_command(&child)) { > + logerror("daemon access hook '%s' failed to start", > + access_hook); > + goto error_return; > + } > + if (strbuf_read(&buf, child.out, 0) < 0) { > + logerror("failed to read from pipe to daemon access hook '%s'", > + access_hook); > + strbuf_reset(&buf); > + seen_errors = 1; > + } > + if (close(child.out) < 0) { > + logerror("failed to close pipe to daemon access hook '%s'", > + access_hook); > + seen_errors = 1; > + } > + if (finish_command(&child)) > + seen_er