handle hashed command socket names (v2)

With the new hashed command socket names (e85898415c), it's possible to
have something like below;

[caglar@qop:~/go/src/github.com/lxc/go-lxc(master)] cat /proc/net/unix | grep lxc
0000000000000000: 00000002 00000000 00010000 0001 01 53465 @lxc/d086e835c86f4b8d/command
[...]

list_active_containers reads /proc/net/unix to find all running
containers but this new format no longer includes the container name or
its lxcpath.

This patch introduces two new commands (LXC_CMD_GET_NAME and
LXC_CMD_GET_LXCPATH) and starts to use those in list_active_containers
call.

changes since v1:
 - added sanity check proposed by Serge

Signed-off-by: S.Çağlar Onur <caglar@10ur.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>

diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index f46efc55fb1b6f0bec447df93b4bfde8e38e8492..28456145aa6590f1ae08cf85d26e75355e18b529 100644 (file)
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -75,13 +75,22 @@
 lxc_log_define(lxc_commands, lxc);
 
 static int fill_sock_name(char *path, int len, const char *name,
-                         const char *lxcpath)
+                         const char *lxcpath, const char *hashed_sock_name)
 {
        char *tmppath;
        size_t tmplen;
        uint64_t hash;
        int ret;
 
+       if (hashed_sock_name != NULL) {
+               ret = snprintf(path, len, "lxc/%s/command", hashed_sock_name);
+               if (ret < 0 || ret >= len) {
+                       ERROR("Error writing to command sock path");
+                       return -1;
+               }
+               return 0;
+       }
+
        if (!lxcpath) {
                lxcpath = lxc_global_config_value("lxc.lxcpath");
                if (!lxcpath) {
@@ -89,9 +98,8 @@ static int fill_sock_name(char *path, int len, const char *name,
                        return -1;
                }
        }
-               
-       ret = snprintf(path, len, "%s/%s/command", lxcpath, name);
 
+       ret = snprintf(path, len, "%s/%s/command", lxcpath, name);
        if (ret < 0) {
                ERROR("Error writing to command sock path");
                return -1;
@@ -108,7 +116,7 @@ static int fill_sock_name(char *path, int len, const char *name,
                return -1;
        }
        hash = fnv_64a_buf(tmppath, ret, FNV1A_64_INIT);
-       ret = snprintf(path, len, "lxc/%016" PRIx64 "/cmd_sock", hash);
+       ret = snprintf(path, len, "lxc/%016" PRIx64 "/command", hash);
        if (ret < 0 || ret >= len) {
                ERROR("Command socket name too long");
                return -1;
@@ -127,6 +135,8 @@ static const char *lxc_cmd_str(lxc_cmd_t cmd)
                [LXC_CMD_GET_CLONE_FLAGS] = "get_clone_flags",
                [LXC_CMD_GET_CGROUP]      = "get_cgroup",
                [LXC_CMD_GET_CONFIG_ITEM] = "get_config_item",
+               [LXC_CMD_GET_NAME]        = "get_name",
+               [LXC_CMD_GET_LXCPATH]     = "get_lxcpath",
        };
 
        if (cmd >= LXC_CMD_MAX)
@@ -259,7 +269,7 @@ static int lxc_cmd_rsp_send(int fd, struct lxc_cmd_rsp *rsp)
  * returned in the cmd response structure.
  */
 static int lxc_cmd(const char *name, struct lxc_cmd_rr *cmd, int *stopped,
-                  const char *lxcpath)
+                  const char *lxcpath, const char *hashed_sock_name)
 {
        int sock, ret = -1;
        char path[sizeof(((struct sockaddr_un *)0)->sun_path)] = { 0 };
@@ -270,7 +280,7 @@ static int lxc_cmd(const char *name, struct lxc_cmd_rr *cmd, int *stopped,
        *stopped = 0;
 
        len = sizeof(path)-1;
-       if (fill_sock_name(offset, len, name, lxcpath))
+       if (fill_sock_name(offset, len, name, lxcpath, hashed_sock_name))
                return -1;
 
        sock = lxc_abstract_unix_connect(path);
@@ -329,7 +339,7 @@ int lxc_try_cmd(const char *name, const char *lxcpath)
                .req = { .cmd = LXC_CMD_GET_INIT_PID },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
 
        if (stopped)
                return 0;
@@ -369,7 +379,7 @@ pid_t lxc_cmd_get_init_pid(const char *name, const char *lxcpath)
                .req = { .cmd = LXC_CMD_GET_INIT_PID },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0)
                return ret;
 
@@ -399,7 +409,7 @@ int lxc_cmd_get_clone_flags(const char *name, const char *lxcpath)
                .req = { .cmd = LXC_CMD_GET_CLONE_FLAGS },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0)
                return ret;
 
@@ -438,7 +448,7 @@ char *lxc_cmd_get_cgroup_path(const char *name, const char *lxcpath,
                },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0)
                return NULL;
 
@@ -497,7 +507,7 @@ char *lxc_cmd_get_config_item(const char *name, const char *item,
                       },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0)
                return NULL;
 
@@ -548,7 +558,7 @@ lxc_state_t lxc_cmd_get_state(const char *name, const char *lxcpath)
                .req = { .cmd = LXC_CMD_GET_STATE }
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0 && stopped)
                return STOPPED;
 
@@ -589,7 +599,7 @@ int lxc_cmd_stop(const char *name, const char *lxcpath)
                .req = { .cmd = LXC_CMD_STOP },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0) {
                if (stopped) {
                        INFO("'%s' is already stopped", name);
@@ -650,7 +660,7 @@ int lxc_cmd_console_winch(const char *name, const char *lxcpath)
                .req = { .cmd = LXC_CMD_CONSOLE_WINCH },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0)
                return ret;
 
@@ -685,7 +695,7 @@ int lxc_cmd_console(const char *name, int *ttynum, int *fd, const char *lxcpath)
                .req = { .cmd = LXC_CMD_CONSOLE, .data = INT_TO_PTR(*ttynum) },
        };
 
-       ret = lxc_cmd(name, &cmd, &stopped, lxcpath);
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
        if (ret < 0)
                return ret;
 
@@ -744,7 +754,81 @@ out_close:
        return 1;
 }
 
+/*
+ * lxc_cmd_get_name: Returns the name of the container
+ *
+ * @hashed_sock_name: hashed socket name
+ *
+ * Returns the name on success, NULL on failure.
+ */
+char *lxc_cmd_get_name(const char *hashed_sock_name)
+{
+       int ret, stopped;
+       struct lxc_cmd_rr cmd = {
+               .req = { .cmd = LXC_CMD_GET_NAME},
+       };
+
+       ret = lxc_cmd(NULL, &cmd, &stopped, NULL, hashed_sock_name);
+       if (ret < 0) {
+               return NULL;
+       }
+
+       if (cmd.rsp.ret == 0)
+               return cmd.rsp.data;
+       return NULL;
+}
+
+static int lxc_cmd_get_name_callback(int fd, struct lxc_cmd_req *req,
+                                           struct lxc_handler *handler)
+{
+       struct lxc_cmd_rsp rsp;
+
+       memset(&rsp, 0, sizeof(rsp));
+
+       rsp.data = handler->name;
+       rsp.datalen = strlen(handler->name) + 1;
+       rsp.ret = 0;
+
+       return lxc_cmd_rsp_send(fd, &rsp);
+}
+
+/*
+ * lxc_cmd_get_lxcpath: Returns the lxcpath of the container
+ *
+ * @hashed_sock_name: hashed socket name
+ *
+ * Returns the lxcpath on success, NULL on failure.
+ */
+char *lxc_cmd_get_lxcpath(const char *hashed_sock_name)
+{
+       int ret, stopped;
+       struct lxc_cmd_rr cmd = {
+               .req = { .cmd = LXC_CMD_GET_LXCPATH},
+       };
 
+       ret = lxc_cmd(NULL, &cmd, &stopped, NULL, hashed_sock_name);
+       if (ret < 0) {
+               return NULL;
+       }
+
+       if (cmd.rsp.ret == 0)
+               return cmd.rsp.data;
+       return NULL;
+}
+
+static int lxc_cmd_get_lxcpath_callback(int fd, struct lxc_cmd_req *req,
+                                       struct lxc_handler *handler)
+{
+       struct lxc_cmd_rsp rsp;
+
+       memset(&rsp, 0, sizeof(rsp));
+
+       rsp.data = (char *)handler->lxcpath;
+       rsp.datalen = strlen(handler->lxcpath) + 1;
+       rsp.ret = 0;
+
+       return lxc_cmd_rsp_send(fd, &rsp);
+}
 
 static int lxc_cmd_process(int fd, struct lxc_cmd_req *req,
                           struct lxc_handler *handler)
@@ -760,6 +844,8 @@ static int lxc_cmd_process(int fd, struct lxc_cmd_req *req,
                [LXC_CMD_GET_CLONE_FLAGS] = lxc_cmd_get_clone_flags_callback,
                [LXC_CMD_GET_CGROUP]      = lxc_cmd_get_cgroup_callback,
                [LXC_CMD_GET_CONFIG_ITEM] = lxc_cmd_get_config_item_callback,
+               [LXC_CMD_GET_NAME]        = lxc_cmd_get_name_callback,
+               [LXC_CMD_GET_LXCPATH]     = lxc_cmd_get_lxcpath_callback,
        };
 
        if (req->cmd >= LXC_CMD_MAX) {
@@ -887,7 +973,7 @@ int lxc_cmd_init(const char *name, struct lxc_handler *handler,
        int len;
 
        len = sizeof(path)-1;
-       if (fill_sock_name(offset, len, name, lxcpath))
+       if (fill_sock_name(offset, len, name, lxcpath, NULL))
                return -1;
 
        fd = lxc_abstract_unix_open(path, SOCK_STREAM, 0);

diff --git a/src/lxc/commands.h b/src/lxc/commands.h
index 9efe2ad4304d4af64c0a1551dbc7bba61382781e..e11a1398386435272ad1ff9a8b4ae4f8877dd063 100644 (file)
--- a/src/lxc/commands.h
+++ b/src/lxc/commands.h
@@ -41,6 +41,8 @@ typedef enum {
        LXC_CMD_GET_CLONE_FLAGS,
        LXC_CMD_GET_CGROUP,
        LXC_CMD_GET_CONFIG_ITEM,
+       LXC_CMD_GET_NAME,
+       LXC_CMD_GET_LXCPATH,
        LXC_CMD_MAX,
 } lxc_cmd_t;
 
@@ -77,6 +79,8 @@ extern char *lxc_cmd_get_cgroup_path(const char *name, const char *lxcpath,
                        const char *subsystem);
 extern int lxc_cmd_get_clone_flags(const char *name, const char *lxcpath);
 extern char *lxc_cmd_get_config_item(const char *name, const char *item, const char *lxcpath);
+extern char *lxc_cmd_get_name(const char *hashed_sock);
+extern char *lxc_cmd_get_lxcpath(const char *hashed_sock);
 extern pid_t lxc_cmd_get_init_pid(const char *name, const char *lxcpath);
 extern lxc_state_t lxc_cmd_get_state(const char *name, const char *lxcpath);
 extern int lxc_cmd_stop(const char *name, const char *lxcpath);

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index ed6f8de977e84c075b770f7438bf793c4961cabe..ee8f491ad93f5a56a606de85071d057225262da0 100644 (file)
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -4217,6 +4217,7 @@ int list_active_containers(const char *lxcpath, char ***nret,
        char **ct_name = NULL;
        size_t len = 0;
        struct lxc_container *c;
+       bool is_hashed;
 
        if (!lxcpath)
                lxcpath = lxc_global_config_value("lxc.lxcpath");
@@ -4232,6 +4233,7 @@ int list_active_containers(const char *lxcpath, char ***nret,
                return -1;
 
        while (getline(&line, &len, f) != -1) {
+
                char *p = strrchr(line, ' '), *p2;
                if (!p)
                        continue;
@@ -4239,9 +4241,17 @@ int list_active_containers(const char *lxcpath, char ***nret,
                if (*p != 0x40)
                        continue;
                p++;
-               if (strncmp(p, lxcpath, lxcpath_len) != 0)
+
+               is_hashed = false;
+               if (strncmp(p, lxcpath, lxcpath_len) == 0) {
+                       p += lxcpath_len;
+               } else if (strncmp(p, "lxc/", 4) == 0) {
+                       p += 4;
+                       is_hashed = true;
+               } else {
                        continue;
-               p += lxcpath_len;
+               }
+
                while (*p == '/')
                        p++;
 
@@ -4251,6 +4261,12 @@ int list_active_containers(const char *lxcpath, char ***nret,
                        continue;
                *p2 = '\0';
 
+               if (is_hashed) {
+                       if (strncmp(lxcpath, lxc_cmd_get_lxcpath(p), lxcpath_len) != 0)
+                               continue;
+                       p = lxc_cmd_get_name(p);
+               }
+
                if (array_contains(&ct_name, p, ct_name_cnt))
                        continue;