attach: cleanup

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/attach.c b/src/lxc/attach.c
index 7b07dce440497874d31ade9f149df72e03a4471f..e9030e3482500caacc61a19c6f60c43e01c49902 100644 (file)
--- a/src/lxc/attach.c
+++ b/src/lxc/attach.c
@@ -58,10 +58,10 @@ static struct lxc_proc_context_info *lxc_proc_get_context_info(pid_t pid)
 {
        __do_free char *line = NULL;
        __do_fclose FILE *proc_file = NULL;
+       __do_free struct lxc_proc_context_info *info = NULL;
        int ret;
        bool found;
        char proc_fn[LXC_PROC_STATUS_LEN];
-       struct lxc_proc_context_info *info;
        size_t line_bufsz = 0;
 
        /* Read capabilities. */
@@ -69,11 +69,9 @@ static struct lxc_proc_context_info *lxc_proc_get_context_info(pid_t pid)
        if (ret < 0 || ret >= LXC_PROC_STATUS_LEN)
                return NULL;
 
-       proc_file = fopen(proc_fn, "r");
-       if (!proc_file) {
-               SYSERROR("Failed to open %s", proc_fn);
-               return NULL;
-       }
+       proc_file = fopen(proc_fn, "re");
+       if (!proc_file)
+               return log_error_errno(NULL, errno, "Failed to open %s", proc_fn);
 
        info = calloc(1, sizeof(*info));
        if (!info)
@@ -89,17 +87,14 @@ static struct lxc_proc_context_info *lxc_proc_get_context_info(pid_t pid)
                }
        }
 
-       if (!found) {
-               ERROR("Could not read capability bounding set from %s", proc_fn);
-               free(info);
-               return NULL;
-       }
+       if (!found)
+               return log_error_errno(NULL, ENOENT, "Failed to read capability bounding set from %s", proc_fn);
 
        info->lsm_label = lsm_process_label_get(pid);
        info->ns_inherited = 0;
        memset(info->ns_fd, -1, sizeof(int) * LXC_NS_MAX);
 
-       return info;
+       return move_ptr(info);
 }
 
 static inline void lxc_proc_close_ns_fd(struct lxc_proc_context_info *ctx)
@@ -172,18 +167,17 @@ static int in_same_namespace(pid_t pid1, pid_t pid2, const char *ns)
 
 static int lxc_attach_to_ns(pid_t pid, struct lxc_proc_context_info *ctx)
 {
-       int i, ret;
+       for (int i = 0; i < LXC_NS_MAX; i++) {
+               int ret;
 
-       for (i = 0; i < LXC_NS_MAX; i++) {
                if (ctx->ns_fd[i] < 0)
                        continue;
 
                ret = setns(ctx->ns_fd[i], ns_info[i].clone_flag);
-               if (ret < 0) {
-                       SYSERROR("Failed to attach to %s namespace of %d",
-                                ns_info[i].proc_name, pid);
-                       return -1;
-               }
+               if (ret < 0)
+                       return log_error_errno(-1,
+                                              errno, "Failed to attach to %s namespace of %d",
+                                              ns_info[i].proc_name, pid);
 
                DEBUG("Attached to %s namespace of %d", ns_info[i].proc_name, pid);
        }
@@ -196,10 +190,8 @@ int lxc_attach_remount_sys_proc(void)
        int ret;
 
        ret = unshare(CLONE_NEWNS);
-       if (ret < 0) {
-               SYSERROR("Failed to unshare mount namespace");
-               return -1;
-       }
+       if (ret < 0)
+               return log_error_errno(-1, errno, "Failed to unshare mount namespace");
 
        if (detect_shared_rootfs()) {
                if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL)) {
@@ -210,50 +202,40 @@ int lxc_attach_remount_sys_proc(void)
 
        /* Assume /proc is always mounted, so remount it. */
        ret = umount2("/proc", MNT_DETACH);
-       if (ret < 0) {
-               SYSERROR("Failed to unmount /proc");
-               return -1;
-       }
+       if (ret < 0)
+               return log_error_errno(-1, errno, "Failed to unmount /proc");
 
        ret = mount("none", "/proc", "proc", 0, NULL);
-       if (ret < 0) {
-               SYSERROR("Failed to remount /proc");
-               return -1;
-       }
+       if (ret < 0)
+               return log_error_errno(-1, errno, "Failed to remount /proc");
 
-       /* Try to umount /sys. If it's not a mount point, we'll get EINVAL, then
+       /*
+        * Try to umount /sys. If it's not a mount point, we'll get EINVAL, then
         * we ignore it because it may not have been mounted in the first place.
         */
        ret = umount2("/sys", MNT_DETACH);
-       if (ret < 0 && errno != EINVAL) {
-               SYSERROR("Failed to unmount /sys");
-               return -1;
-       } else if (ret == 0) {
-               /* Remount it. */
-               ret = mount("none", "/sys", "sysfs", 0, NULL);
-               if (ret < 0) {
-                       SYSERROR("Failed to remount /sys");
-                       return -1;
-               }
-       }
+       if (ret < 0 && errno != EINVAL)
+               return log_error_errno(-1, errno, "Failed to unmount /sys");
+
+       /* Remount it. */
+       if (ret == 0 && mount("none", "/sys", "sysfs", 0, NULL))
+               return log_error_errno(-1, errno, "Failed to remount /sys");
 
        return 0;
 }
 
 static int lxc_attach_drop_privs(struct lxc_proc_context_info *ctx)
 {
-       int cap, last_cap;
+       int last_cap;
 
        last_cap = lxc_caps_last_cap();
-       for (cap = 0; cap <= last_cap; cap++) {
+       for (int cap = 0; cap <= last_cap; cap++) {
                if (ctx->capability_mask & (1LL << cap))
                        continue;
 
                if (prctl(PR_CAPBSET_DROP, prctl_arg(cap), prctl_arg(0),
-                         prctl_arg(0), prctl_arg(0))) {
-                       SYSERROR("Failed to drop capability %d", cap);
-                       return -1;
-               }
+                         prctl_arg(0), prctl_arg(0)))
+                       return log_error_errno(-1, errno, "Failed to drop capability %d", cap);
 
                TRACE("Dropped capability %d", cap);
        }
@@ -310,8 +292,7 @@ static int lxc_attach_set_environment(struct lxc_proc_context_info *init_ctx,
                                free(extra_keep_store);
                        }
 
-                       ERROR("Failed to clear environment");
-                       return -1;
+                       return log_error(-1, "Failed to clear environment");
                }
 
                if (extra_keep_store) {
@@ -343,10 +324,8 @@ static int lxc_attach_set_environment(struct lxc_proc_context_info *init_ctx,
        }
 
        ret = putenv("container=lxc");
-       if (ret < 0) {
-               SYSWARN("Failed to set environment variable");
-               return -1;
-       }
+       if (ret < 0)
+               return log_warn(-1, errno, "Failed to set environment variable");
 
        /* Set container environment variables.*/
        if (init_ctx && init_ctx->container && init_ctx->container->lxc_conf) {
@@ -358,10 +337,8 @@ static int lxc_attach_set_environment(struct lxc_proc_context_info *init_ctx,
                                return -1;
 
                        ret = putenv(env_tmp);
-                       if (ret < 0) {
-                               SYSERROR("Failed to set environment variable: %s", (char *)iterator->elem);
-                               return -1;
-                       }
+                       if (ret < 0)
+                               return log_error_errno(-1, errno, "Failed to set environment variable: %s", (char *)iterator->elem);
                }
        }
 

diff --git a/src/lxc/log.h b/src/lxc/log.h
index db4129493ddecda3f88dcfbcf52ba8fe97a32916..545626e46fe4e5816f316af52bb1f290237faebe 100644 (file)
--- a/src/lxc/log.h
+++ b/src/lxc/log.h
@@ -510,6 +510,12 @@ __lxc_unused static inline void LXC_##LEVEL(struct lxc_log_locinfo* locinfo,       \
                __ret__;                                \
        })
 
+#define log_warn(__ret__, __errno__, format, ...) \
+       ({                                        \
+               WARN(format, ##__VA_ARGS__);      \
+               __ret__;                          \
+       })
+
 #define log_debug_errno(__ret__, __errno__, format, ...) \
        ({                                               \
                errno = __errno__;                       \