daemon: opt-out on features that require posix

Windows does not supply the POSIX-functions fork(), setuuid(), setgid(),
setsid() and initgroups(). Error out if --user or --detach is specified
when if so.

MinGW doesn't have prototypes and headers for inet_ntop and inet_pton,
so include our implementation instead. MSVC does, so avoid doing so
there.

Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Makefile b/Makefile
index 46034bfc47c99157acffaaa8fa86a56441a7ff8a..53986b1ecb76fcb30a51c4fc1a86a49ca6549724 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -401,6 +401,7 @@ EXTRA_PROGRAMS =
 # ... and all the rest that could be moved out of bindir to gitexecdir
 PROGRAMS += $(EXTRA_PROGRAMS)
 
+PROGRAM_OBJS += daemon.o
 PROGRAM_OBJS += fast-import.o
 PROGRAM_OBJS += imap-send.o
 PROGRAM_OBJS += shell.o
@@ -1066,7 +1067,6 @@ ifeq ($(uname_S),Windows)
        NO_SVN_TESTS = YesPlease
        NO_PERL_MAKEMAKER = YesPlease
        RUNTIME_PREFIX = YesPlease
-       NO_POSIX_ONLY_PROGRAMS = YesPlease
        NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
        NO_NSEC = YesPlease
        USE_WIN32_MMAP = YesPlease
@@ -1077,6 +1077,7 @@ ifeq ($(uname_S),Windows)
        NO_CURL = YesPlease
        NO_PYTHON = YesPlease
        BLK_SHA1 = YesPlease
+       NO_POSIX_GOODIES = UnfortunatelyYes
        NATIVE_CRLF = YesPlease
 
        CC = compat/vcbuild/scripts/clink.pl
@@ -1119,7 +1120,6 @@ ifneq (,$(findstring MINGW,$(uname_S)))
        NO_SVN_TESTS = YesPlease
        NO_PERL_MAKEMAKER = YesPlease
        RUNTIME_PREFIX = YesPlease
-       NO_POSIX_ONLY_PROGRAMS = YesPlease
        NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
        NO_NSEC = YesPlease
        USE_WIN32_MMAP = YesPlease
@@ -1130,6 +1130,9 @@ ifneq (,$(findstring MINGW,$(uname_S)))
        NO_PYTHON = YesPlease
        BLK_SHA1 = YesPlease
        ETAGS_TARGET = ETAGS
+       NO_INET_PTON = YesPlease
+       NO_INET_NTOP = YesPlease
+       NO_POSIX_GOODIES = UnfortunatelyYes
        COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/fnmatch -Icompat/win32
        COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
        COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/winansi.o \
@@ -1249,9 +1252,6 @@ ifdef ZLIB_PATH
 endif
 EXTLIBS += -lz
 
-ifndef NO_POSIX_ONLY_PROGRAMS
-       PROGRAM_OBJS += daemon.o
-endif
 ifndef NO_OPENSSL
        OPENSSL_LIBSSL = -lssl
        ifdef OPENSSLDIR
@@ -1419,6 +1419,10 @@ ifdef NO_DEFLATE_BOUND
        BASIC_CFLAGS += -DNO_DEFLATE_BOUND
 endif
 
+ifdef NO_POSIX_GOODIES
+       BASIC_CFLAGS += -DNO_POSIX_GOODIES
+endif
+
 ifdef BLK_SHA1
        SHA1_HEADER = "block-sha1/sha1.h"
        LIB_OBJS += block-sha1/sha1.o

diff --git a/daemon.c b/daemon.c
index 17028b6de8c9285c7aa2c2865b84153519633e4a..13435b46674a3a7b123597ab11751459173f3325 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -940,6 +940,62 @@ static void sanitize_stdfds(void)
                close(fd);
 }
 
+#ifdef NO_POSIX_GOODIES
+
+struct credentials;
+
+static void drop_privileges(struct credentials *cred)
+{
+       /* nothing */
+}
+
+static void daemonize(void)
+{
+       die("--detach not supported on this platform");
+}
+
+static struct credentials *prepare_credentials(const char *user_name,
+    const char *group_name)
+{
+       die("--user not supported on this platform");
+}
+
+#else
+
+struct credentials {
+       struct passwd *pass;
+       gid_t gid;
+};
+
+static void drop_privileges(struct credentials *cred)
+{
+       if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
+           setgid (cred->gid) || setuid(cred->pass->pw_uid)))
+               die("cannot drop privileges");
+}
+
+static struct credentials *prepare_credentials(const char *user_name,
+    const char *group_name)
+{
+       static struct credentials c;
+
+       c.pass = getpwnam(user_name);
+       if (!c.pass)
+               die("user not found - %s", user_name);
+
+       if (!group_name)
+               c.gid = c.pass->pw_gid;
+       else {
+               struct group *group = getgrnam(group_name);
+               if (!group)
+                       die("group not found - %s", group_name);
+
+               c.gid = group->gr_gid;
+       }
+
+       return &c;
+}
+
 static void daemonize(void)
 {
        switch (fork()) {
@@ -957,6 +1013,7 @@ static void daemonize(void)
        close(2);
        sanitize_stdfds();
 }
+#endif
 
 static void store_pid(const char *path)
 {
@@ -967,7 +1024,8 @@ static void store_pid(const char *path)
                die_errno("failed to write pid file '%s'", path);
 }
 
-static int serve(struct string_list *listen_addr, int listen_port, struct passwd *pass, gid_t gid)
+static int serve(struct string_list *listen_addr, int listen_port,
+    struct credentials *cred)
 {
        struct socketlist socklist = { NULL, 0, 0 };
 
@@ -976,10 +1034,7 @@ static int serve(struct string_list *listen_addr, int listen_port, struct passwd
                die("unable to allocate any listen sockets on port %u",
                    listen_port);
 
-       if (pass && gid &&
-           (initgroups(pass->pw_name, gid) || setgid (gid) ||
-            setuid(pass->pw_uid)))
-               die("cannot drop privileges");
+       drop_privileges(cred);
 
        return service_loop(&socklist);
 }
@@ -991,9 +1046,7 @@ int main(int argc, char **argv)
        int serve_mode = 0, 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;
+       struct credentials *cred = NULL;
        int i;
 
        git_extract_argv0_path(argv[0]);
@@ -1139,21 +1192,8 @@ int main(int argc, char **argv)
        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 (user_name)
+               cred = prepare_credentials(user_name, group_name);
 
        if (strict_paths && (!ok_paths || !*ok_paths))
                die("option --strict-paths requires a whitelist");
@@ -1187,5 +1227,5 @@ int main(int argc, char **argv)
        cld_argv[argc] = "--serve";
        cld_argv[argc+1] = NULL;
 
-       return serve(&listen_addr, listen_port, pass, gid);
+       return serve(&listen_addr, listen_port, cred);
 }