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From f065b88b17bd569dda412b2e6f34d921f7badb79 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Fri, 13 Mar 2015 21:22:05 -0500
Subject: [PATCH] sd-daemon: simplify sd_pid_notify_with_fds
Coverity was complaining that CMSG_NXTHDR is used without
checking the return value. In this case it cannot fail, but
it is a good excuse to simplify the function a bit.
CID #1261726.
(cherry picked from commit 64144440a5d2d94482f882b992fd2a4e0dca7a05)
http://lists.freedesktop.org/archives/systemd-devel/2015-April/031348.html
Cherry-picked from: c1258d6
Resolves: #1222517
---
src/libsystemd/sd-daemon/sd-daemon.c | 61 ++++++++++++++++--------------------
1 file changed, 27 insertions(+), 34 deletions(-)
diff --git a/src/libsystemd/sd-daemon/sd-daemon.c b/src/libsystemd/sd-daemon/sd-daemon.c
index 22a3a5347..1474321c9 100644
--- a/src/libsystemd/sd-daemon/sd-daemon.c
+++ b/src/libsystemd/sd-daemon/sd-daemon.c
@@ -352,12 +352,10 @@ _public_ int sd_pid_notify_with_fds(pid_t pid, int unset_environment, const char
.msg_iovlen = 1,
.msg_name = &sockaddr,
};
- struct cmsghdr *control;
_cleanup_close_ int fd = -1;
struct cmsghdr *cmsg = NULL;
const char *e;
- size_t controllen_without_ucred = 0;
- bool try_without_ucred = false;
+ bool have_pid;
int r;
if (!state) {
@@ -396,42 +394,37 @@ _public_ int sd_pid_notify_with_fds(pid_t pid, int unset_environment, const char
if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
msghdr.msg_namelen = sizeof(struct sockaddr_un);
- control = alloca(CMSG_SPACE(sizeof(struct ucred)) + CMSG_SPACE(sizeof(int) * n_fds));
+ have_pid = pid != 0 && pid != getpid();
- if (n_fds > 0) {
- msghdr.msg_control = control;
- msghdr.msg_controllen = CMSG_LEN(sizeof(int) * n_fds);
+ if (n_fds > 0 || have_pid) {
+ msghdr.msg_controllen = CMSG_SPACE(sizeof(int) * n_fds) +
+ CMSG_SPACE(sizeof(struct ucred) * have_pid);
+ msghdr.msg_control = alloca(msghdr.msg_controllen);
cmsg = CMSG_FIRSTHDR(&msghdr);
- cmsg->cmsg_level = SOL_SOCKET;
- cmsg->cmsg_type = SCM_RIGHTS;
- cmsg->cmsg_len = CMSG_LEN(sizeof(int) * n_fds);
+ if (n_fds > 0) {
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(int) * n_fds);
- memcpy(CMSG_DATA(cmsg), fds, sizeof(int) * n_fds);
- }
-
- if (pid != 0 && pid != getpid()) {
- struct ucred *ucred;
-
- try_without_ucred = true;
- controllen_without_ucred = msghdr.msg_controllen;
+ memcpy(CMSG_DATA(cmsg), fds, sizeof(int) * n_fds);
- msghdr.msg_control = control;
- msghdr.msg_controllen += CMSG_LEN(sizeof(struct ucred));
+ if (have_pid)
+ assert_se(cmsg = CMSG_NXTHDR(&msghdr, cmsg));
+ }
- if (cmsg)
- cmsg = CMSG_NXTHDR(&msghdr, cmsg);
- else
- cmsg = CMSG_FIRSTHDR(&msghdr);
+ if (have_pid) {
+ struct ucred *ucred;
- cmsg->cmsg_level = SOL_SOCKET;
- cmsg->cmsg_type = SCM_CREDENTIALS;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_CREDENTIALS;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
- ucred = (struct ucred*) CMSG_DATA(cmsg);
- ucred->pid = pid;
- ucred->uid = getuid();
- ucred->gid = getgid();
+ ucred = (struct ucred*) CMSG_DATA(cmsg);
+ ucred->pid = pid;
+ ucred->uid = getuid();
+ ucred->gid = getgid();
+ }
}
/* First try with fake ucred data, as requested */
@@ -441,10 +434,10 @@ _public_ int sd_pid_notify_with_fds(pid_t pid, int unset_environment, const char
}
/* If that failed, try with our own ucred instead */
- if (try_without_ucred) {
- if (controllen_without_ucred <= 0)
+ if (have_pid) {
+ msghdr.msg_controllen -= CMSG_SPACE(sizeof(struct ucred));
+ if (msghdr.msg_controllen == 0)
msghdr.msg_control = NULL;
- msghdr.msg_controllen = controllen_without_ucred;
if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) >= 0) {
r = 1;