- conversion of virtfs-proxy-helper from libcap to libcap-ng

- removal of libcap-dev from docker, travis and gitlab CI
 - removal of deprecate "-virtfs_synth" option
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Merge remote-tracking branch 'remotes/gkurz/tags/9p-next-2019-12-12' into staging

- conversion of virtfs-proxy-helper from libcap to libcap-ng
- removal of libcap-dev from docker, travis and gitlab CI
- removal of deprecate "-virtfs_synth" option

# gpg: Signature made Thu 12 Dec 2019 19:55:53 GMT
# gpg:                using RSA key B4828BAF943140CEF2A3491071D4D5E5822F73D6
# gpg: Good signature from "Greg Kurz <groug@kaod.org>" [full]
# gpg:                 aka "Gregory Kurz <gregory.kurz@free.fr>" [full]
# gpg:                 aka "[jpeg image of size 3330]" [full]
# Primary key fingerprint: B482 8BAF 9431 40CE F2A3  4910 71D4 D5E5 822F 73D6

* remotes/gkurz/tags/9p-next-2019-12-12:
  virtfs: Remove the deprecated "-virtfs_synth" option
  travis.yml: Drop libcap-dev
  ci: Use libcap-ng
  docker: remove libcap development packages
  virtfs-proxy-helper: switch from libcap to libcap-ng

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

.gitlab-ci.yml

@@ -59,7 +59,7 @@ build-user:
 
 build-clang:
  script:
- - apt-get install -y -qq clang libsdl2-dev libattr1-dev libcap-dev
+ - apt-get install -y -qq clang libsdl2-dev libattr1-dev libcap-ng-dev
       xfslibs-dev libiscsi-dev libnfs-dev libseccomp-dev gnutls-dev librbd-dev
  - ./configure --cc=clang --cxx=clang++ --enable-werror
       --target-list="alpha-softmmu arm-softmmu m68k-softmmu mips64-softmmu

.travis.yml

@@ -26,7 +26,6 @@ addons:
       - libaio-dev
       - libattr1-dev
       - libbrlapi-dev
-      - libcap-dev
       - libcap-ng-dev
       - libgcc-4.8-dev
       - libgnutls28-dev

Makefile

@@ -575,7 +575,6 @@ qemu-keymap$(EXESUF): qemu-keymap.o ui/input-keymap.o $(COMMON_LDADDS)
 qemu-edid$(EXESUF): qemu-edid.o hw/display/edid-generate.o $(COMMON_LDADDS)
 
 fsdev/virtfs-proxy-helper$(EXESUF): fsdev/virtfs-proxy-helper.o fsdev/9p-marshal.o fsdev/9p-iov-marshal.o $(COMMON_LDADDS)
-fsdev/virtfs-proxy-helper$(EXESUF): LIBS += -lcap
 
 scsi/qemu-pr-helper$(EXESUF): scsi/qemu-pr-helper.o scsi/utils.o $(authz-obj-y) $(crypto-obj-y) $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS)
 ifdef CONFIG_MPATH

configure

@@ -3863,22 +3863,6 @@ else
   mpathpersist=no
 fi
 
-##########################################
-# libcap probe
-
-if test "$cap" != "no" ; then
-  cat > $TMPC <<EOF
-#include <stdio.h>
-#include <sys/capability.h>
-int main(void) { cap_t caps; caps = cap_init(); return caps != NULL; }
-EOF
-  if compile_prog "" "-lcap" ; then
-    cap=yes
-  else
-    cap=no
-  fi
-fi
-
 ##########################################
 # pthread probe
 PTHREADLIBS_LIST="-pthread -lpthread -lpthreadGC2"
@@ -6204,12 +6188,12 @@ if test "$want_tools" = "yes" ; then
 fi
 if test "$softmmu" = yes ; then
   if test "$linux" = yes; then
-    if test "$virtfs" != no && test "$cap" = yes && test "$attr" = yes ; then
+    if test "$virtfs" != no && test "$cap_ng" = yes && test "$attr" = yes ; then
       virtfs=yes
       tools="$tools fsdev/virtfs-proxy-helper\$(EXESUF)"
     else
       if test "$virtfs" = yes; then
-        error_exit "VirtFS requires libcap devel and libattr devel"
+        error_exit "VirtFS requires libcap-ng devel and libattr devel"
       fi
       virtfs=no
     fi

fsdev/virtfs-proxy-helper.c

@@ -13,7 +13,6 @@
 #include <sys/resource.h>
 #include <getopt.h>
 #include <syslog.h>
-#include <sys/capability.h>
 #include <sys/fsuid.h>
 #include <sys/vfs.h>
 #include <sys/ioctl.h>
@@ -21,6 +20,7 @@
 #ifdef CONFIG_LINUX_MAGIC_H
 #include <linux/magic.h>
 #endif
+#include <cap-ng.h>
 #include "qemu-common.h"
 #include "qemu/sockets.h"
 #include "qemu/xattr.h"
@@ -79,49 +79,10 @@ static void do_perror(const char *string)
     }
 }
 
-static int do_cap_set(cap_value_t *cap_value, int size, int reset)
-{
-    cap_t caps;
-    if (reset) {
-        /*
-         * Start with an empty set and set permitted and effective
-         */
-        caps = cap_init();
-        if (caps == NULL) {
-            do_perror("cap_init");
-            return -1;
-        }
-        if (cap_set_flag(caps, CAP_PERMITTED, size, cap_value, CAP_SET) < 0) {
-            do_perror("cap_set_flag");
-            goto error;
-        }
-    } else {
-        caps = cap_get_proc();
-        if (!caps) {
-            do_perror("cap_get_proc");
-            return -1;
-        }
-    }
-    if (cap_set_flag(caps, CAP_EFFECTIVE, size, cap_value, CAP_SET) < 0) {
-        do_perror("cap_set_flag");
-        goto error;
-    }
-    if (cap_set_proc(caps) < 0) {
-        do_perror("cap_set_proc");
-        goto error;
-    }
-    cap_free(caps);
-    return 0;
-
-error:
-    cap_free(caps);
-    return -1;
-}
-
 static int init_capabilities(void)
 {
     /* helper needs following capabilities only */
-    cap_value_t cap_list[] = {
+    int cap_list[] = {
         CAP_CHOWN,
         CAP_DAC_OVERRIDE,
         CAP_FOWNER,
@@ -130,7 +91,34 @@ static int init_capabilities(void)
         CAP_MKNOD,
         CAP_SETUID,
     };
-    return do_cap_set(cap_list, ARRAY_SIZE(cap_list), 1);
+    int i;
+
+    capng_clear(CAPNG_SELECT_BOTH);
+    for (i = 0; i < ARRAY_SIZE(cap_list); i++) {
+        if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
+                         cap_list[i]) < 0) {
+            do_perror("capng_update");
+            return -1;
+        }
+    }
+    if (capng_apply(CAPNG_SELECT_BOTH) < 0) {
+        do_perror("capng_apply");
+        return -1;
+    }
+
+    /* Prepare effective set for setugid.  */
+    for (i = 0; i < ARRAY_SIZE(cap_list); i++) {
+        if (cap_list[i] == CAP_DAC_OVERRIDE) {
+            continue;
+        }
+
+        if (capng_update(CAPNG_DROP, CAPNG_EFFECTIVE,
+                         cap_list[i]) < 0) {
+            do_perror("capng_update");
+            return -1;
+        }
+    }
+    return 0;
 }
 
 static int socket_read(int sockfd, void *buff, ssize_t size)
@@ -295,14 +283,6 @@ static int setugid(int uid, int gid, int *suid, int *sgid)
 {
     int retval;
 
-    /*
-     * We still need DAC_OVERRIDE because we don't change
-     * supplementary group ids, and hence may be subjected DAC rules
-     */
-    cap_value_t cap_list[] = {
-        CAP_DAC_OVERRIDE,
-    };
-
     *suid = geteuid();
     *sgid = getegid();
 
@@ -316,11 +296,21 @@ static int setugid(int uid, int gid, int *suid, int *sgid)
         goto err_sgid;
     }
 
-    if (uid != 0 || gid != 0) {
+    if (uid == 0 && gid == 0) {
-        if (do_cap_set(cap_list, ARRAY_SIZE(cap_list), 0) < 0) {
+        /* Linux has already copied the permitted set to the effective set.  */
-            retval = -errno;
+        return 0;
-            goto err_suid;
+    }
-        }
+
+    /*
+     * All capabilities have been cleared from the effective set.  However
+     * we still need DAC_OVERRIDE because we don't change supplementary
+     * group ids, and hence may be subject to DAC rules.  init_capabilities
+     * left the set of capabilities that we want in libcap-ng's state.
+     */
+    if (capng_apply(CAPNG_SELECT_CAPS) < 0) {
+        retval = -errno;
+        do_perror("capng_apply");
+        goto err_suid;
     }
     return 0;
 

qemu-deprecated.texi

@@ -89,11 +89,6 @@ error in the future.
 The @code{-realtime mlock=on|off} argument has been replaced by the
 @code{-overcommit mem-lock=on|off} argument.
 
-@subsection -virtfs_synth (since 4.1)
-
-The ``-virtfs_synth'' argument is now deprecated. Please use ``-fsdev synth''
-and ``-device virtio-9p-...'' instead.
-
 @subsection -numa node,mem=@var{size} (since 4.1)
 
 The parameter @option{mem} of @option{-numa node} is used to assign a part of

qemu-options.hx

@@ -1468,16 +1468,6 @@ would still return entries from other devices).
 @end table
 ETEXI
 
-DEF("virtfs_synth", 0, QEMU_OPTION_virtfs_synth,
-    "-virtfs_synth Create synthetic file system image\n",
-    QEMU_ARCH_ALL)
-STEXI
-@item -virtfs_synth
-@findex -virtfs_synth
-Create synthetic file system image. Note that this option is now deprecated.
-Please use @code{-fsdev synth} and @code{-device virtio-9p-...} instead.
-ETEXI
-
 DEF("iscsi", HAS_ARG, QEMU_OPTION_iscsi,
     "-iscsi [user=user][,password=password]\n"
     "       [,header-digest=CRC32C|CR32C-NONE|NONE-CRC32C|NONE\n"

tests/docker/dockerfiles/fedora.docker

@@ -25,7 +25,6 @@ ENV PACKAGES \
     libasan \
     libattr-devel \
     libblockdev-mpath-devel \
-    libcap-devel \
     libcap-ng-devel \
     libcurl-devel \
     libfdt-devel \

tests/docker/dockerfiles/ubuntu.docker

@@ -23,7 +23,6 @@ ENV PACKAGES flex bison \
     libbrlapi-dev \
     libbz2-dev \
     libcacard-dev \
-    libcap-dev \
     libcap-ng-dev \
     libcurl4-gnutls-dev \
     libdrm-dev \

tests/docker/dockerfiles/ubuntu1804.docker

@@ -12,7 +12,6 @@ ENV PACKAGES flex bison \
     libbrlapi-dev \
     libbz2-dev \
     libcacard-dev \
-    libcap-dev \
     libcap-ng-dev \
     libcurl4-gnutls-dev \
     libdrm-dev \

vl.c

@@ -3374,29 +3374,6 @@ int main(int argc, char **argv, char **envp)
                              qemu_opt_get(opts, "mount_tag"), &error_abort);
                 break;
             }
-            case QEMU_OPTION_virtfs_synth: {
-                QemuOpts *fsdev;
-                QemuOpts *device;
-
-                warn_report("'-virtfs_synth' is deprecated, please use "
-                             "'-fsdev synth' and '-device virtio-9p-...' "
-                            "instead");
-
-                fsdev = qemu_opts_create(qemu_find_opts("fsdev"), "v_synth",
-                                         1, NULL);
-                if (!fsdev) {
-                    error_report("duplicate option: %s", "virtfs_synth");
-                    exit(1);
-                }
-                qemu_opt_set(fsdev, "fsdriver", "synth", &error_abort);
-
-                device = qemu_opts_create(qemu_find_opts("device"), NULL, 0,
-                                          &error_abort);
-                qemu_opt_set(device, "driver", "virtio-9p-pci", &error_abort);
-                qemu_opt_set(device, "fsdev", "v_synth", &error_abort);
-                qemu_opt_set(device, "mount_tag", "v_synth", &error_abort);
-                break;
-            }
             case QEMU_OPTION_serial:
                 add_device_config(DEV_SERIAL, optarg);
                 default_serial = 0;