Merge pull request #15579 from DaanDeMeyer/sd-bus-get-name/owner-creds-docs

util-lib: check for /proc being mounted in some really basic fs operations

man/rules/meson.build

@@ -262,6 +262,7 @@ manpages = [
   ['sd_bus_get_events', 'sd_bus_get_timeout', 'sd_bus_set_fd'],
   ''],
  ['sd_bus_get_n_queued_read', '3', ['sd_bus_get_n_queued_write'], ''],
+ ['sd_bus_get_name_creds', '3', ['sd_bus_get_owner_creds'], ''],
  ['sd_bus_get_name_machine_id', '3', [], ''],
  ['sd_bus_is_open', '3', ['sd_bus_is_ready'], ''],
  ['sd_bus_list_names', '3', [], ''],

man/sd-bus.xml

@@ -83,6 +83,8 @@
 <citerefentry><refentrytitle>sd_bus_get_method_call_timeout</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_get_n_queued_read</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_get_name_machine_id</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>sd_bus_get_name_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_get_scope</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_get_tid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_get_unique_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

man/sd_bus_get_name_creds.xml

@@ -0,0 +1,120 @@
+<?xml version='1.0'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
+
+<refentry id="sd_bus_get_name_creds" xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>sd_bus_get_name_creds</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>sd_bus_get_name_creds</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>sd_bus_get_name_creds</refname>
+    <refname>sd_bus_get_owner_creds</refname>
+
+    <refpurpose>Query bus client credentials</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_get_name_creds</function></funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+        <paramdef>const char *<parameter>name</parameter></paramdef>
+        <paramdef>uint64_t <parameter>mask</parameter></paramdef>
+        <paramdef>sd_bus_creds **<parameter>creds</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_get_owner_creds</function></funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+        <paramdef>uint64_t <parameter>mask</parameter></paramdef>
+        <paramdef>sd_bus_creds **<parameter>creds</parameter></paramdef>
+      </funcprototype>
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><function>sd_bus_get_name_creds()</function> queries the credentials of the bus client
+    identified by <parameter>name</parameter>. The <parameter>mask</parameter> parameter is a combo of
+    <constant index='false'>SD_BUS_CREDS_*</constant> flags that indicate which credential info the caller is
+    interested in. See
+    <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    for a list of possible flags. On success, <parameter>creds</parameter> contains a new
+    <structname>sd_bus_creds</structname> instance with the requested information. Ownership of this instance
+    belongs to the caller and it should be freed once no longer needed by calling
+    <function>sd_bus_creds_unref()</function>.</para>
+
+    <para><function>sd_bus_get_owner_creds()</function> queries the credentials of the creator of the given
+    bus. The <parameter>mask</parameter> and <parameter>creds</parameter> parameters behave the same as in
+    <function>sd_bus_get_name_creds()</function>.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Return Value</title>
+
+    <para>On success, these functions return a non-negative integer. On failure, they return a negative
+    errno-style error code.</para>
+
+    <refsect2>
+      <title>Errors</title>
+
+      <para>Returned errors may indicate the following problems:</para>
+
+      <variablelist>
+        <varlistentry>
+          <term><constant>-EINVAL</constant></term>
+
+          <listitem><para>An argument is invalid.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ENOPKG</constant></term>
+
+          <listitem><para>The bus cannot be resolved.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-EPERM</constant></term>
+
+          <listitem><para>The bus has already been started.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ECHILD</constant></term>
+
+          <listitem><para>The bus was created in a different process.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ENOMEM</constant></term>
+
+          <listitem><para>Memory allocation failed.</para></listitem>
+        </varlistentry>
+      </variablelist>
+    </refsect2>
+  </refsect1>
+
+  <xi:include href="libsystemd-pkgconfig.xml" />
+
+  <refsect1>
+    <title>See Also</title>
+
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>

src/basic/btrfs-util.c

@@ -1149,7 +1149,6 @@ static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol
                 FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
                         _cleanup_free_ char *p = NULL;
                         const struct btrfs_root_ref *ref;
-                        struct btrfs_ioctl_ino_lookup_args ino_args;
 
                         btrfs_ioctl_search_args_set(&args, sh);
 
@@ -1164,9 +1163,10 @@ static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol
                         if (!p)
                                 return -ENOMEM;
 
-                        zero(ino_args);
-                        ino_args.treeid = subvol_id;
-                        ino_args.objectid = htole64(ref->dirid);
+                        struct btrfs_ioctl_ino_lookup_args ino_args = {
+                                .treeid = subvol_id,
+                                .objectid = htole64(ref->dirid),
+                        };
 
                         if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0)
                                 return -errno;
@@ -1504,7 +1504,6 @@ static int subvol_snapshot_children(
 
                 FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) {
                         _cleanup_free_ char *p = NULL, *c = NULL, *np = NULL;
-                        struct btrfs_ioctl_ino_lookup_args ino_args;
                         const struct btrfs_root_ref *ref;
                         _cleanup_close_ int old_child_fd = -1, new_child_fd = -1;
 
@@ -1528,9 +1527,10 @@ static int subvol_snapshot_children(
                         if (!p)
                                 return -ENOMEM;
 
-                        zero(ino_args);
-                        ino_args.treeid = old_subvol_id;
-                        ino_args.objectid = htole64(ref->dirid);
+                        struct btrfs_ioctl_ino_lookup_args ino_args = {
+                                .treeid = old_subvol_id,
+                                .objectid = htole64(ref->dirid),
+                        };
 
                         if (ioctl(old_fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0)
                                 return -errno;

src/basic/fd-util.c

@@ -21,9 +21,10 @@
 #include "path-util.h"
 #include "process-util.h"
 #include "socket-util.h"
+#include "stat-util.h"
 #include "stdio-util.h"
-#include "util.h"
 #include "tmpfile-util.h"
+#include "util.h"
 
 /* The maximum number of iterations in the loop to close descriptors in the fallback case
  * when /proc/self/fd/ is inaccessible. */
@@ -939,8 +940,15 @@ int fd_reopen(int fd, int flags) {
 
         xsprintf(procfs_path, "/proc/self/fd/%i", fd);
         new_fd = open(procfs_path, flags);
-        if (new_fd < 0)
-                return -errno;
+        if (new_fd < 0) {
+                if (errno != ENOENT)
+                        return -errno;
+
+                if (proc_mounted() == 0)
+                        return -ENOSYS; /* if we have no /proc/, the concept is not implementable */
+
+                return -ENOENT;
+        }
 
         return new_fd;
 }

src/basic/fs-util.c

@@ -337,8 +337,15 @@ int fchmod_opath(int fd, mode_t m) {
          * fchownat() does. */
 
         xsprintf(procfs_path, "/proc/self/fd/%i", fd);
-        if (chmod(procfs_path, m) < 0)
-                return -errno;
+        if (chmod(procfs_path, m) < 0) {
+                if (errno != ENOENT)
+                        return -errno;
+
+                if (proc_mounted() == 0)
+                        return -ENOSYS; /* if we have no /proc/, the concept is not implementable */
+
+                return -ENOENT;
+        }
 
         return 0;
 }

src/basic/socket-util.c

@@ -887,7 +887,7 @@ ssize_t receive_one_fd_iov(
                 .msg_iov = iov,
                 .msg_iovlen = iovlen,
         };
-        struct cmsghdr *cmsg, *found = NULL;
+        struct cmsghdr *found;
         ssize_t k;
 
         assert(transport_fd >= 0);
@@ -905,16 +905,7 @@ ssize_t receive_one_fd_iov(
         if (k < 0)
                 return k;
 
-        CMSG_FOREACH(cmsg, &mh) {
-                if (cmsg->cmsg_level == SOL_SOCKET &&
-                    cmsg->cmsg_type == SCM_RIGHTS &&
-                    cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
-                        assert(!found);
-                        found = cmsg;
-                        break;
-                }
-        }
-
+        found = cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, CMSG_LEN(sizeof(int)));
         if (!found) {
                 cmsg_close_all(&mh);
 

src/basic/socket-util.h

@@ -158,6 +158,14 @@ int flush_accept(int fd);
 
 struct cmsghdr* cmsg_find(struct msghdr *mh, int level, int type, socklen_t length);
 
+/* Type-safe, dereferencing version of cmsg_find() */
+#define CMSG_FIND_DATA(mh, level, type, ctype) \
+        ({                                                            \
+                struct cmsghdr *_found;                               \
+                _found = cmsg_find(mh, level, type, CMSG_LEN(sizeof(ctype))); \
+                (ctype*) (_found ? CMSG_DATA(_found) : NULL);         \
+        })
+
 /*
  * Certain hardware address types (e.g Infiniband) do not fit into sll_addr
  * (8 bytes) and run over the structure. This macro returns the correct size that

src/basic/stat-util.c

@@ -178,13 +178,12 @@ int fd_is_fs_type(int fd, statfs_f_type_t magic_value) {
 }
 
 int path_is_fs_type(const char *path, statfs_f_type_t magic_value) {
-        _cleanup_close_ int fd = -1;
+        struct statfs s;
 
-        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_PATH);
-        if (fd < 0)
+        if (statfs(path, &s) < 0)
                 return -errno;
 
-        return fd_is_fs_type(fd, magic_value);
+        return is_fs_type(&s, magic_value);
 }
 
 bool is_temporary_fs(const struct statfs *s) {
@@ -377,3 +376,15 @@ int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret
 
         return 0;
 }
+
+int proc_mounted(void) {
+        int r;
+
+        /* A quick check of procfs is properly mounted */
+
+        r = path_is_fs_type("/proc/", PROC_SUPER_MAGIC);
+        if (r == -ENOENT) /* not mounted at all */
+                return false;
+
+        return r;
+}

src/basic/stat-util.h

@@ -87,3 +87,5 @@ int fd_verify_directory(int fd);
 int device_path_make_major_minor(mode_t mode, dev_t devno, char **ret);
 int device_path_make_canonical(mode_t mode, dev_t devno, char **ret);
 int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret_devno);
+
+int proc_mounted(void);

src/coredump/coredump.c

@@ -921,19 +921,11 @@ static int process_socket(int fd) {
                 /* The final zero-length datagram carries the file descriptor and tells us
                  * that we're done. */
                 if (n == 0) {
-                        struct cmsghdr *cmsg, *found = NULL;
+                        struct cmsghdr *found;
 
                         free(iovec.iov_base);
 
-                        CMSG_FOREACH(cmsg, &mh) {
-                                if (cmsg->cmsg_level == SOL_SOCKET &&
-                                    cmsg->cmsg_type == SCM_RIGHTS &&
-                                    cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
-                                        assert(!found);
-                                        found = cmsg;
-                                }
-                        }
-
+                        found = cmsg_find(&mh, SOL_SOCKET, SCM_RIGHTS, CMSG_LEN(sizeof(int)));
                         if (!found) {
                                 cmsg_close_all(&mh);
                                 r = log_error_errno(SYNTHETIC_ERRNO(EBADMSG),

src/import/importd.c

@@ -557,9 +557,8 @@ static int manager_on_notify(sd_event_source *s, int fd, uint32_t revents, void
                 .msg_control = &control,
                 .msg_controllen = sizeof(control),
         };
-        struct ucred *ucred = NULL;
+        struct ucred *ucred;
         Manager *m = userdata;
-        struct cmsghdr *cmsg;
         char *p, *e;
         Transfer *t;
         Iterator i;
@@ -574,17 +573,12 @@ static int manager_on_notify(sd_event_source *s, int fd, uint32_t revents, void
 
         cmsg_close_all(&msghdr);
 
-        CMSG_FOREACH(cmsg, &msghdr)
-                if (cmsg->cmsg_level == SOL_SOCKET &&
-                    cmsg->cmsg_type == SCM_CREDENTIALS &&
-                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
-                        ucred = (struct ucred*) CMSG_DATA(cmsg);
-
         if (msghdr.msg_flags & MSG_TRUNC) {
                 log_warning("Got overly long notification datagram, ignoring.");
                 return 0;
         }
 
+        ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
         if (!ucred || ucred->pid <= 0) {
                 log_warning("Got notification datagram lacking credential information, ignoring.");
                 return 0;

src/initctl/initctl.c

@@ -246,9 +246,10 @@ static int server_init(Server *s, unsigned n_sockets) {
         assert(s);
         assert(n_sockets > 0);
 
-        zero(*s);
+        *s = (struct Server) {
+                .epoll_fd = epoll_create1(EPOLL_CLOEXEC),
+        };
 
-        s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
         if (s->epoll_fd < 0) {
                 r = log_error_errno(errno,
                                     "Failed to create epoll object: %m");
@@ -256,7 +257,6 @@ static int server_init(Server *s, unsigned n_sockets) {
         }
 
         for (i = 0; i < n_sockets; i++) {
-                struct epoll_event ev;
                 Fifo *f;
                 int fd;
 
@@ -283,9 +283,11 @@ static int server_init(Server *s, unsigned n_sockets) {
 
                 f->fd = -1;
 
-                zero(ev);
-                ev.events = EPOLLIN;
-                ev.data.ptr = f;
+                struct epoll_event ev = {
+                        .events = EPOLLIN,
+                        .data.ptr = f,
+                };
+
                 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
                         r = -errno;
                         fifo_free(f);

src/journal/journalctl.c

@@ -1783,7 +1783,6 @@ static int setup_keys(void) {
         int fd = -1, r;
         sd_id128_t machine, boot;
         char *p = NULL, *k = NULL;
-        struct FSSHeader h;
         uint64_t n;
         struct stat st;
 
@@ -1873,15 +1872,17 @@ static int setup_keys(void) {
         if (r < 0)
                 log_warning_errno(r, "Failed to set file attributes: %m");
 
-        zero(h);
+        struct FSSHeader h = {
+                .machine_id = machine,
+                .boot_id = boot,
+                .header_size = htole64(sizeof(h)),
+                .start_usec = htole64(n * arg_interval),
+                .interval_usec = htole64(arg_interval),
+                .fsprg_secpar = htole16(FSPRG_RECOMMENDED_SECPAR),
+                .fsprg_state_size = htole64(state_size),
+        };
+
         memcpy(h.signature, "KSHHRHLP", 8);
-        h.machine_id = machine;
-        h.boot_id = boot;
-        h.header_size = htole64(sizeof(h));
-        h.start_usec = htole64(n * arg_interval);
-        h.interval_usec = htole64(arg_interval);
-        h.fsprg_secpar = htole16(FSPRG_RECOMMENDED_SECPAR);
-        h.fsprg_state_size = htole64(state_size);
 
         r = loop_write(fd, &h, sizeof(h), false);
         if (r < 0) {

src/journal/journald-stream.c

@@ -491,8 +491,7 @@ static int stdout_stream_scan(StdoutStream *s, bool force_flush) {
 static int stdout_stream_process(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
         StdoutStream *s = userdata;
-        struct ucred *ucred = NULL;
-        struct cmsghdr *cmsg;
+        struct ucred *ucred;
         struct iovec iovec;
         size_t limit;
         ssize_t l;
@@ -541,25 +540,14 @@ static int stdout_stream_process(sd_event_source *es, int fd, uint32_t revents,
                 goto terminate;
         }
 
-        CMSG_FOREACH(cmsg, &msghdr)
-                if (cmsg->cmsg_level == SOL_SOCKET &&
-                    cmsg->cmsg_type == SCM_CREDENTIALS &&
-                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
-                        assert(!ucred);
-                        ucred = (struct ucred *)CMSG_DATA(cmsg);
-                        break;
-                }
-
-        /* Invalidate the context if the pid of the sender changed.
-         * This happens when a forked process inherits stdout / stderr
-         * from a parent. In this case getpeercred returns the ucred
-         * of the parent, which can be invalid if the parent has exited
-         * in the meantime.
+        /* Invalidate the context if the pid of the sender changed.  This happens when a forked process
+         * inherits stdout / stderr from a parent. In this case getpeercred returns the ucred of the parent,
+         * which can be invalid if the parent has exited in the meantime.
          */
+        ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
         if (ucred && ucred->pid != s->ucred.pid) {
-                /* force out any previously half-written lines from a
-                 * different process, before we switch to the new ucred
-                 * structure for everything we just added */
+                /* force out any previously half-written lines from a different process, before we switch to
+                 * the new ucred structure for everything we just added */
                 r = stdout_stream_scan(s, true);
                 if (r < 0)
                         goto terminate;

src/journal/mmap-cache.c

@@ -162,7 +162,7 @@ static Window *window_add(MMapCache *m, MMapFileDescriptor *f, int prot, bool ke
         if (!m->last_unused || m->n_windows <= WINDOWS_MIN) {
 
                 /* Allocate a new window */
-                w = new0(Window, 1);
+                w = new(Window, 1);
                 if (!w)
                         return NULL;
                 m->n_windows++;
@@ -171,16 +171,17 @@ static Window *window_add(MMapCache *m, MMapFileDescriptor *f, int prot, bool ke
                 /* Reuse an existing one */
                 w = m->last_unused;
                 window_unlink(w);
-                zero(*w);
         }
 
-        w->cache = m;
-        w->fd = f;
-        w->prot = prot;
-        w->keep_always = keep_always;
-        w->offset = offset;
-        w->size = size;
-        w->ptr = ptr;
+        *w = (Window) {
+                .cache = m,
+                .fd = f,
+                .prot = prot,
+                .keep_always = keep_always,
+                .offset = offset,
+                .size = size,
+                .ptr = ptr,
+        };
 
         LIST_PREPEND(by_fd, f->windows, w);
 

src/libsystemd-network/icmp6-util.c

@@ -167,9 +167,9 @@ int icmp6_receive(int fd, void *buffer, size_t size, struct in6_addr *dst,
 
         iov = IOVEC_MAKE(buffer, size);
 
-        len = recvmsg(fd, &msg, MSG_DONTWAIT);
+        len = recvmsg_safe(fd, &msg, MSG_DONTWAIT);
         if (len < 0)
-                return -errno;
+                return (int) len;
 
         if ((size_t) len != size)
                 return -EINVAL;

src/libsystemd-network/sd-dhcp-client.c

@@ -1927,25 +1927,21 @@ static int client_receive_message_raw(
 
         iov = IOVEC_MAKE(packet, buflen);
 
-        len = recvmsg(fd, &msg, 0);
-        if (len < 0) {
-                if (IN_SET(errno, EAGAIN, EINTR, ENETDOWN))
-                        return 0;
-
-                return log_dhcp_client_errno(client, errno,
+        len = recvmsg_safe(fd, &msg, 0);
+        if (IN_SET(len, -EAGAIN, -EINTR, -ENETDOWN))
+                return 0;
+        if (len < 0)
+                return log_dhcp_client_errno(client, len,
                                              "Could not receive message from raw socket: %m");
-        } else if ((size_t)len < sizeof(DHCPPacket))
+
+        if ((size_t) len < sizeof(DHCPPacket))
                 return 0;
 
-        CMSG_FOREACH(cmsg, &msg)
-                if (cmsg->cmsg_level == SOL_PACKET &&
-                    cmsg->cmsg_type == PACKET_AUXDATA &&
-                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct tpacket_auxdata))) {
-                        struct tpacket_auxdata *aux = (struct tpacket_auxdata*)CMSG_DATA(cmsg);
-
-                        checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
-                        break;
-                }
+        cmsg = cmsg_find(&msg, SOL_PACKET, PACKET_AUXDATA, CMSG_LEN(sizeof(struct tpacket_auxdata)));
+        if (cmsg) {
+                struct tpacket_auxdata *aux = (struct tpacket_auxdata*) CMSG_DATA(cmsg);
+                checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
+        }
 
         r = dhcp_packet_verify_headers(packet, len, checksum, client->port);
         if (r < 0)

src/libsystemd-network/sd-dhcp-server.c

@@ -995,14 +995,12 @@ static int server_receive_message(sd_event_source *s, int fd,
 
         iov = IOVEC_MAKE(message, buflen);
 
-        len = recvmsg(fd, &msg, 0);
-        if (len < 0) {
-                if (IN_SET(errno, EAGAIN, EINTR))
-                        return 0;
-
-                return -errno;
-        }
-        if ((size_t)len < sizeof(DHCPMessage))
+        len = recvmsg_safe(fd, &msg, 0);
+        if (IN_SET(len, -EAGAIN, -EINTR))
+                return 0;
+        if (len < 0)
+                return len;
+        if ((size_t) len < sizeof(DHCPMessage))
                 return 0;
 
         CMSG_FOREACH(cmsg, &msg) {

src/libsystemd/sd-bus/bus-introspect.c

@@ -13,8 +13,9 @@
 int introspect_begin(struct introspect *i, bool trusted) {
         assert(i);
 
-        zero(*i);
-        i->trusted = trusted;
+        *i = (struct introspect) {
+                .trusted = trusted,
+        };
 
         i->f = open_memstream_unlocked(&i->introspection, &i->size);
         if (!i->f)

src/libsystemd/sd-bus/bus-socket.c

@@ -136,11 +136,10 @@ static int bus_socket_write_auth(sd_bus *b) {
         if (b->prefer_writev)
                 k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index);
         else {
-                struct msghdr mh;
-                zero(mh);
-
-                mh.msg_iov = b->auth_iovec + b->auth_index;
-                mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index;
+                struct msghdr mh = {
+                        .msg_iov = b->auth_iovec + b->auth_index,
+                        .msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index,
+                };
 
                 k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
                 if (k < 0 && errno == ENOTSOCK) {
@@ -551,11 +550,12 @@ static int bus_socket_read_auth(sd_bus *b) {
         if (b->prefer_readv)
                 k = readv(b->input_fd, &iov, 1);
         else {
-                zero(mh);
-                mh.msg_iov = &iov;
-                mh.msg_iovlen = 1;
-                mh.msg_control = &control;
-                mh.msg_controllen = sizeof(control);
+                mh = (struct msghdr) {
+                        .msg_iov = &iov,
+                        .msg_iovlen = 1,
+                        .msg_control = &control,
+                        .msg_controllen = sizeof(control),
+                };
 
                 k = recvmsg_safe(b->input_fd, &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
                 if (k == -ENOTSOCK) {
@@ -1194,11 +1194,12 @@ int bus_socket_read_message(sd_bus *bus) {
         if (bus->prefer_readv)
                 k = readv(bus->input_fd, &iov, 1);
         else {
-                zero(mh);
-                mh.msg_iov = &iov;
-                mh.msg_iovlen = 1;
-                mh.msg_control = &control;
-                mh.msg_controllen = sizeof(control);
+                mh = (struct msghdr) {
+                        .msg_iov = &iov,
+                        .msg_iovlen = 1,
+                        .msg_control = &control,
+                        .msg_controllen = sizeof(control),
+                };
 
                 k = recvmsg_safe(bus->input_fd, &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
                 if (k == -ENOTSOCK) {

src/libsystemd/sd-netlink/netlink-socket.c

@@ -238,7 +238,7 @@ int socket_write_message(sd_netlink *nl, sd_netlink_message *m) {
         return k;
 }
 
-static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool peek) {
+static int socket_recv_message(int fd, struct iovec *iov, uint32_t *ret_mcast_group, bool peek) {
         union sockaddr_union sender;
         uint8_t cmsg_buffer[CMSG_SPACE(sizeof(struct nl_pktinfo))];
         struct msghdr msg = {
@@ -249,8 +249,6 @@ static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool
                 .msg_control = cmsg_buffer,
                 .msg_controllen = sizeof(cmsg_buffer),
         };
-        struct cmsghdr *cmsg;
-        uint32_t group = 0;
         ssize_t n;
 
         assert(fd >= 0);
@@ -281,20 +279,16 @@ static int socket_recv_message(int fd, struct iovec *iov, uint32_t *_group, bool
                 return 0;
         }
 
-        CMSG_FOREACH(cmsg, &msg) {
-                if (cmsg->cmsg_level == SOL_NETLINK &&
-                    cmsg->cmsg_type == NETLINK_PKTINFO &&
-                    cmsg->cmsg_len == CMSG_LEN(sizeof(struct nl_pktinfo))) {
-                        struct nl_pktinfo *pktinfo = (void *)CMSG_DATA(cmsg);
+        if (ret_mcast_group) {
+                struct cmsghdr *cmsg;
 
-                        /* multi-cast group */
-                        group = pktinfo->group;
-                }
+                cmsg = cmsg_find(&msg, SOL_NETLINK, NETLINK_PKTINFO, CMSG_LEN(sizeof(struct nl_pktinfo)));
+                if (ret_mcast_group)
+                        *ret_mcast_group = ((struct nl_pktinfo*) CMSG_DATA(cmsg))->group;
+                else
+                        *ret_mcast_group = 0;
         }
 
-        if (_group)
-                *_group = group;
-
         return (int) n;
 }
 

src/nspawn/nspawn.c

@@ -3698,8 +3698,7 @@ static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t r
                 .msg_control = &control,
                 .msg_controllen = sizeof(control),
         };
-        struct cmsghdr *cmsg;
-        struct ucred *ucred = NULL;
+        struct ucred *ucred;
         ssize_t n;
         pid_t inner_child_pid;
         _cleanup_strv_free_ char **tags = NULL;
@@ -3721,15 +3720,7 @@ static int nspawn_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t r
 
         cmsg_close_all(&msghdr);
 
-        CMSG_FOREACH(cmsg, &msghdr) {
-                if (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 = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
         if (!ucred || ucred->pid != inner_child_pid) {
                 log_debug("Received notify message without valid credentials. Ignoring.");
                 return 0;

src/shared/ask-password-api.c

@@ -860,7 +860,6 @@ int ask_password_agent(
 
         for (;;) {
                 char passphrase[LINE_MAX+1];
-                struct msghdr msghdr;
                 struct iovec iovec;
                 struct ucred *ucred;
                 union {
@@ -919,11 +918,12 @@ int ask_password_agent(
                 iovec = IOVEC_MAKE(passphrase, sizeof(passphrase));
 
                 zero(control);
-                zero(msghdr);
-                msghdr.msg_iov = &iovec;
-                msghdr.msg_iovlen = 1;
-                msghdr.msg_control = &control;
-                msghdr.msg_controllen = sizeof(control);
+                struct msghdr msghdr = {
+                        .msg_iov = &iovec,
+                        .msg_iovlen = 1,
+                        .msg_control = &control,
+                        .msg_controllen = sizeof(control),
+                };
 
                 n = recvmsg_safe(socket_fd, &msghdr, 0);
                 if (IN_SET(n, -EAGAIN, -EINTR))
@@ -940,15 +940,12 @@ int ask_password_agent(
                         continue;
                 }
 
-                if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
-                    control.cmsghdr.cmsg_level != SOL_SOCKET ||
-                    control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
-                    control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
+                ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
+                if (!ucred) {
                         log_debug("Received message without credentials. Ignoring.");
                         continue;
                 }
 
-                ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
                 if (ucred->uid != 0) {
                         log_debug("Got request from unprivileged user. Ignoring.");
                         continue;

src/shared/socket-netlink.c

@@ -243,8 +243,9 @@ int socket_address_parse_netlink(SocketAddress *a, const char *s) {
         assert(a);
         assert(s);
 
-        zero(*a);
-        a->type = SOCK_RAW;
+        *a = (SocketAddress) {
+                .type = SOCK_RAW,
+        };
 
         r = extract_first_word(&s, &word, NULL, 0);
         if (r < 0)

src/sysusers/sysusers.c

@@ -1443,7 +1443,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         if (name) {
                 r = specifier_printf(name, specifier_table, NULL, &resolved_name);
                 if (r < 0)
-                        log_error_errno(r, "[%s:%u] Failed to replace specifiers: %s", fname, line, name);
+                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers in '%s': %m", fname, line, name);
 
                 if (!valid_user_group_name(resolved_name, 0))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
@@ -1458,7 +1458,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         if (id) {
                 r = specifier_printf(id, specifier_table, NULL, &resolved_id);
                 if (r < 0)
-                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers: %s",
+                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers in '%s': %m",
                                                fname, line, name);
         }
 
@@ -1469,7 +1469,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         if (description) {
                 r = specifier_printf(description, specifier_table, NULL, &resolved_description);
                 if (r < 0)
-                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers: %s",
+                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers in '%s': %m",
                                                fname, line, description);
 
                 if (!valid_gecos(resolved_description))
@@ -1485,7 +1485,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         if (home) {
                 r = specifier_printf(home, specifier_table, NULL, &resolved_home);
                 if (r < 0)
-                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers: %s",
+                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers in '%s': %m",
                                                fname, line, home);
 
                 if (!valid_home(resolved_home))
@@ -1501,7 +1501,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         if (shell) {
                 r = specifier_printf(shell, specifier_table, NULL, &resolved_shell);
                 if (r < 0)
-                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers: %s",
+                        return log_error_errno(r, "[%s:%u] Failed to replace specifiers in '%s': %m",
                                                fname, line, shell);
 
                 if (!valid_shell(resolved_shell))

src/tmpfiles/tmpfiles.c

@@ -1078,6 +1078,11 @@ static int fd_set_acls(Item *item, int fd, const char *path, const struct stat *
 
         if (r > 0)
                 return -r; /* already warned */
+
+        /* The above procfs paths don't work if /proc is not mounted. */
+        if (r == -ENOENT && proc_mounted() == 0)
+                r = -ENOSYS;
+
         if (r == -EOPNOTSUPP) {
                 log_debug_errno(r, "ACLs not supported by file system at %s", path);
                 return 0;
@@ -2556,7 +2561,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer, bool
         if (r < 0) {
                 if (IN_SET(r, -EINVAL, -EBADSLT))
                         *invalid_config = true;
-                return log_error_errno(r, "[%s:%u] Failed to replace specifiers: %s", fname, line, path);
+                return log_error_errno(r, "[%s:%u] Failed to replace specifiers in '%s': %m", fname, line, path);
         }
 
         r = patch_var_run(fname, line, &i.path);

src/udev/udevd.c

@@ -916,9 +916,8 @@ static int on_worker(sd_event_source *s, int fd, uint32_t revents, void *userdat
                         .msg_control = &control,
                         .msg_controllen = sizeof(control),
                 };
-                struct cmsghdr *cmsg;
                 ssize_t size;
-                struct ucred *ucred = NULL;
+                struct ucred *ucred;
                 struct worker *worker;
 
                 size = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT);
@@ -937,12 +936,7 @@ static int on_worker(sd_event_source *s, int fd, uint32_t revents, void *userdat
                         continue;
                 }
 
-                CMSG_FOREACH(cmsg, &msghdr)
-                        if (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 = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
                 if (!ucred || ucred->pid <= 0) {
                         log_warning("Ignoring worker message without valid PID");
                         continue;

travis-ci/managers/fuzzit.sh

@@ -48,10 +48,30 @@ FUZZIT_ARGS="--type ${FUZZING_TYPE} --branch ${FUZZIT_BRANCH} --revision ${TRAVI
 wget -O fuzzit https://github.com/fuzzitdev/fuzzit/releases/latest/download/fuzzit_Linux_x86_64
 chmod +x fuzzit
 
-find out/ -maxdepth 1 -name 'fuzz-*' -executable -type f -exec basename '{}' \; | xargs --verbose -n1 -I%FUZZER% ./fuzzit create job ${FUZZIT_ARGS} %FUZZER%-asan-ubsan out/%FUZZER% ${FUZZIT_ADDITIONAL_FILES}
+# Simple wrapper which retries given command up to three times if it fails
+_retry() {
+    local EC=1
+
+    for _ in {0..2}; do
+        if "$@"; then
+            EC=0
+            break
+        fi
+
+        sleep 1
+    done
+
+    return $EC
+}
+
+find out/ -maxdepth 1 -name 'fuzz-*' -executable -type f -exec basename '{}' \; | while read -r fuzzer; do
+    _retry ./fuzzit create job ${FUZZIT_ARGS} ${fuzzer}-asan-ubsan out/${fuzzer} ${FUZZIT_ADDITIONAL_FILES}
+done
 
 export SANITIZER="memory -fsanitize-memory-track-origins"
 FUZZIT_ARGS="--type ${FUZZING_TYPE} --branch ${FUZZIT_BRANCH} --revision ${TRAVIS_COMMIT}"
 tools/oss-fuzz.sh
 
-find out/ -maxdepth 1 -name 'fuzz-*' -executable -type f -exec basename '{}' \; | xargs --verbose -n1 -I%FUZZER% ./fuzzit create job ${FUZZIT_ARGS} %FUZZER%-msan out/%FUZZER% ${FUZZIT_ADDITIONAL_FILES}
+find out/ -maxdepth 1 -name 'fuzz-*' -executable -type f -exec basename '{}' \; | while read -r fuzzer; do
+    _retry ./fuzzit create job ${FUZZIT_ARGS} ${fuzzer}-msan out/${fuzzer} ${FUZZIT_ADDITIONAL_FILES}
+done