[lxc-devel] [PATCH] handle hashed command socket names
S.Çağlar Onur
caglar at 10ur.org
Mon Aug 25 17:36:21 UTC 2014
On Mon, Aug 25, 2014 at 9:39 AM, Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
> Quoting S.Çağlar Onur (caglar at 10ur.org):
>> With the new hashed command socket names (e85898415c), it possible to have have something like below;
>>
>> [caglar at 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.
>>
>> Signed-off-by: S.Çağlar Onur <caglar at 10ur.org>
>
> Thanks Çağlar.
>
> Acked-by: Serge E. Hallyn <serge.hallyn at ubuntu.com>
>
> (Except for one requested change below, can be done inline)
Will add that check and send a new version as I realized that the
commit message contains couple of typos/repetitions as well....
>> ---
>> src/lxc/commands.c | 118 ++++++++++++++++++++++++++++++++++++++++++-------
>> src/lxc/commands.h | 4 ++
>> src/lxc/lxccontainer.c | 20 ++++++++-
>> 3 files changed, 124 insertions(+), 18 deletions(-)
>>
>> diff --git a/src/lxc/commands.c b/src/lxc/commands.c
>> index f46efc5..f56aece 100644
>> --- 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, for sanity since len is passed in. I realize it shouldn't
> be possible, but neither should a mars orbiter crashing due to failure
> to convert units
>
>> + 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);
>
> I guess for any valid non-hashed case lxcpath will start with '/' so that
> sufficient disambiguates the two cases, so this is fine.
>
>> 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 9efe2ad..e11a139 100644
>> --- 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 172e667..9c34120 100644
>> --- a/src/lxc/lxccontainer.c
>> +++ b/src/lxc/lxccontainer.c
>> @@ -3751,6 +3751,7 @@ 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");
>> @@ -3766,6 +3767,7 @@ 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;
>> @@ -3773,9 +3775,17 @@ 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++;
>>
>> @@ -3785,6 +3795,12 @@ 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;
>>
>> --
>> 1.9.1
>>
>> _______________________________________________
>> lxc-devel mailing list
>> lxc-devel at lists.linuxcontainers.org
>> http://lists.linuxcontainers.org/listinfo/lxc-devel
> _______________________________________________
> lxc-devel mailing list
> lxc-devel at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-devel
--
S.Çağlar Onur <caglar at 10ur.org>
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