From: David Turner <dturner@twosigma.com>
To: git@vger.kernel.org
Cc: l.s.r@web.de, David Turner <dturner@twosigma.com>
Subject: [PATCH v3 1/2] use HOST_NAME_MAX to size buffers for gethostname(2)
Date: Tue, 18 Apr 2017 17:57:42 -0400 [thread overview]
Message-ID: <20170418215743.18406-2-dturner@twosigma.com> (raw)
In-Reply-To: <20170418215743.18406-1-dturner@twosigma.com>
From: René Scharfe <l.s.r@web.de>
POSIX limits the length of host names to HOST_NAME_MAX. Export the
fallback definition from daemon.c and use this constant to make all
buffers used with gethostname(2) big enough for any possible result
and a terminating NUL.
Inspired-by: David Turner <dturner@twosigma.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: David Turner <dturner@twosigma.com>
---
builtin/gc.c | 10 +++++++---
builtin/receive-pack.c | 2 +-
daemon.c | 4 ----
fetch-pack.c | 2 +-
git-compat-util.h | 4 ++++
ident.c | 2 +-
6 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/builtin/gc.c b/builtin/gc.c
index c2c61a57bb..4c4a36e2b5 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -238,7 +238,7 @@ static int need_to_gc(void)
static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
{
static struct lock_file lock;
- char my_host[128];
+ char my_host[HOST_NAME_MAX + 1];
struct strbuf sb = STRBUF_INIT;
struct stat st;
uintmax_t pid;
@@ -257,8 +257,12 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
fd = hold_lock_file_for_update(&lock, pidfile_path,
LOCK_DIE_ON_ERROR);
if (!force) {
- static char locking_host[128];
+ static char locking_host[HOST_NAME_MAX + 1];
+ static char *scan_fmt;
int should_exit;
+
+ if (!scan_fmt)
+ scan_fmt = xstrfmt("%s %%%dc", "%"SCNuMAX, HOST_NAME_MAX);
fp = fopen(pidfile_path, "r");
memset(locking_host, 0, sizeof(locking_host));
should_exit =
@@ -274,7 +278,7 @@ static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
* running.
*/
time(NULL) - st.st_mtime <= 12 * 3600 &&
- fscanf(fp, "%"SCNuMAX" %127c", &pid, locking_host) == 2 &&
+ fscanf(fp, scan_fmt, &pid, locking_host) == 2 &&
/* be gentle to concurrent "gc" on remote hosts */
(strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
if (fp != NULL)
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index aca9c33d8d..2612efad3d 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1695,7 +1695,7 @@ static const char *unpack(int err_fd, struct shallow_info *si)
if (status)
return "unpack-objects abnormal exit";
} else {
- char hostname[256];
+ char hostname[HOST_NAME_MAX + 1];
argv_array_pushl(&child.args, "index-pack",
"--stdin", hdr_arg, NULL);
diff --git a/daemon.c b/daemon.c
index 473e6b6b63..1503e1ed6f 100644
--- a/daemon.c
+++ b/daemon.c
@@ -4,10 +4,6 @@
#include "strbuf.h"
#include "string-list.h"
-#ifndef HOST_NAME_MAX
-#define HOST_NAME_MAX 256
-#endif
-
#ifdef NO_INITGROUPS
#define initgroups(x, y) (0) /* nothing */
#endif
diff --git a/fetch-pack.c b/fetch-pack.c
index d07d85ce30..055f568775 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -802,7 +802,7 @@ static int get_pack(struct fetch_pack_args *args,
if (args->use_thin_pack)
argv_array_push(&cmd.args, "--fix-thin");
if (args->lock_pack || unpack_limit) {
- char hostname[256];
+ char hostname[HOST_NAME_MAX + 1];
if (gethostname(hostname, sizeof(hostname)))
xsnprintf(hostname, sizeof(hostname), "localhost");
argv_array_pushf(&cmd.args,
diff --git a/git-compat-util.h b/git-compat-util.h
index 8a4a3f85e7..46f3abe401 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -884,6 +884,10 @@ static inline size_t xsize_t(off_t len)
__attribute__((format (printf, 3, 4)))
extern int xsnprintf(char *dst, size_t max, const char *fmt, ...);
+#ifndef HOST_NAME_MAX
+#define HOST_NAME_MAX 256
+#endif
+
/* in ctype.c, for kwset users */
extern const unsigned char tolower_trans_tbl[256];
diff --git a/ident.c b/ident.c
index c0364fe3a1..556851cf94 100644
--- a/ident.c
+++ b/ident.c
@@ -120,7 +120,7 @@ static int canonical_name(const char *host, struct strbuf *out)
static void add_domainname(struct strbuf *out, int *is_bogus)
{
- char buf[1024];
+ char buf[HOST_NAME_MAX + 1];
if (gethostname(buf, sizeof(buf))) {
warning_errno("cannot get host name");
--
2.11.GIT
next prev parent reply other threads:[~2017-04-18 21:58 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-18 21:57 [PATCH v3 0/2] gethostbyname fixes David Turner
2017-04-18 21:57 ` David Turner [this message]
2017-04-19 1:28 ` [PATCH v3 1/2] use HOST_NAME_MAX to size buffers for gethostname(2) Jonathan Nieder
2017-04-19 2:57 ` Junio C Hamano
2017-04-19 14:03 ` René Scharfe
2017-04-19 17:28 ` René Scharfe
2017-04-19 19:08 ` David Turner
2017-04-19 19:09 ` Torsten Bögershausen
2017-04-19 20:02 ` René Scharfe
2017-04-20 18:37 ` Torsten Bögershausen
2017-04-20 19:28 ` René Scharfe
2017-04-21 4:18 ` Torsten Bögershausen
2017-04-18 21:57 ` [PATCH v3 2/2] xgethostname: handle long hostnames David Turner
2017-04-19 1:35 ` Jonathan Nieder
2017-04-19 2:51 ` Junio C Hamano
2017-04-19 15:50 ` David Turner
2017-04-19 16:43 ` René Scharfe
2017-04-19 2:48 ` Junio C Hamano
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