[tarantool-patches] Re: [PATCH 1/3] Configurable syslog destination

From: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
To: Olga Arkhangelskaia <arkholga@xxxxxxxxxxxxx>
Date: Fri, 13 Jul 2018 16:12:08 +0300

On Fri, Jul 13, 2018 at 01:29:36PM +0300, Olga Arkhangelskaia wrote:

Added server option to syslog configuration.
Server option is responsible for log destination. At the momemt
there is two ways of usage:server=unix:/path/to/socket or
server=ipv4:port. If port is not set default udp port 514 is used.
If logging to syslog is set, however there is no sever options -
default location is used: Linux /dev/log and Mac /var/run/syslog.

Signed-off-by: Olga Arkhangelskaia <arkholga@xxxxxxxxxxxxx>

We don't sign off patches. Please fix your git config.

And we do add a reference to the related GitHub ticket to the commit
message, e.g.

Closes #3487
Needed for #3487
Part of #3487
Follow-up #3487

For more information on preparing and submitting patches, please read:

https://tarantool.io/en/doc/1.9/dev_guide/developer_guidelines/#how-to-write-a-commit-message
https://tarantool.io/en/doc/1.9/dev_guide/developer_guidelines/#how-to-submit-a-patch-for-review

---
src/say.c | 76
++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
src/say.h | 7 ++++++
2 files changed, 75 insertions(+), 8 deletions(-)

diff --git a/src/say.c b/src/say.c
index 43124083c..aa820175c 100644
--- a/src/say.c
+++ b/src/say.c
@@ -451,7 +451,7 @@ log_file_init(struct log *log, const char *init_str)
}

/**
- * Connect to syslogd using UNIX socket.
+ * Connect to UNIX socket.

No point in changing this comment.

  * @param path UNIX socket path.
  * @retval not 0 Socket descriptor.
  * @retval    -1 Socket error.
@@ -473,16 +473,50 @@ syslog_connect_unix(const char *path)
      return fd;
}

+/**
+ * Connect to remote syslogd using server:port.
+ * @param ip:port pair.

If you write a comment for doxygen, please describe each paramter
separately, i.e.

@param remote server address
@param port server port

+ * @retval not 0 Socket descriptor.
+ * @retval    -1 Socket error.
+ */
+static int
+syslog_connect_remote(const char *remote, const char *portnum)
+{
+     /* IPv4 */
+     struct sockaddr_in in;
+     in_addr_t addr = inet_addr(remote);

I think you should use getaddrinfo() to resolve the address.

+     int fd = socket(AF_INET, SOCK_DGRAM, 0);
+     if (fd < 0)
+             return -1;
+     memset(&in, 0, sizeof(in));
+     in.sin_family = AF_INET;
+     in.sin_port = htons(atoi(portnum));
+     in.sin_addr.s_addr = addr;
+     if (connect(fd, (struct sockaddr *) &in, sizeof(in)) != 0) {
+             close(fd);
+             return -1;
+     }
+     return fd;
+}
+
static inline int
log_syslog_connect(struct log *log)
{
+
      /*
-      * Try two locations: '/dev/log' for Linux and
+      * If server option is not se use '/dev/log' for Linux and

^^
typo: se => set

       * '/var/run/syslog' for Mac.
       */
-     log->fd = syslog_connect_unix("/dev/log");
-     if (log->fd < 0)
-             log->fd = syslog_connect_unix("/var/run/syslog");
+     if (strncmp(log->addr_type, "default", sizeof("default")) == 0) {

Comparing strings to determine the socket address looks ugly. Besides,
using strings is troublesome - you have to allocate and free them (which
you forgot BTW). I think you'd better introduce a enum for that.

+ log->fd = syslog_connect_unix("/dev/log");

+ if (log->fd < 0)
+ log->fd =
syslog_connect_unix("/var/run/syslog");

Malformed indentation.

+     } else if (strncmp(log->addr_type, "unix", sizeof("unix")) == 0) {
+             log->fd = syslog_connect_unix(log->addr_path);
+     } else {
+             log->fd = syslog_connect_remote(log->addr_type,
+                                             log->addr_path);
+     }
      return log->fd;
}

@@ -498,6 +532,14 @@ log_syslog_init(struct log *log, const char *init_str)
      if (say_parse_syslog_opts(init_str, &opts) < 0)
              return -1;

+     if (opts.addr_type == NULL &&
+         opts.addr_path == NULL) {
+             log->addr_type = strdup("default");
+     } else {
+             log->addr_type = strdup(opts.addr_type);
+             log->addr_path = strdup(opts.addr_path);
+     }
+

We handle memory allocation errors gracefully in tarantool code.
Even for strdup() and malloc() although they typically never fail.
Please implement error handling.

      if (opts.identity == NULL)
              log->syslog_ident = strdup("tarantool");
      else
@@ -1044,6 +1086,8 @@ say_syslog_facility_by_name(const char *facility)
int
say_parse_syslog_opts(const char *init_str, struct say_syslog_opts *opts)
{
+     opts->addr_type = NULL;
+     opts->addr_path = NULL;
      opts->identity = NULL;
      opts->facility = syslog_facility_MAX;
      opts->copy = strdup(init_str);
@@ -1051,8 +1095,9 @@ say_parse_syslog_opts(const char *init_str, struct
say_syslog_opts *opts)
              diag_set(OutOfMemory, strlen(init_str), "malloc", "opts->copy");
              return -1;
      }
-     char *ptr = opts->copy;
-     const char *option, *value;
+     char *ptr = opts->copy;
+     const char *option, *value, *srv_str;
+     char *srv_ptr, *srv_opt;

      /* strsep() overwrites the separator with '\0' */
      while ((option = strsep(&ptr, ","))) {
@@ -1060,7 +1105,22 @@ say_parse_syslog_opts(const char *init_str, struct
say_syslog_opts *opts)
                      break;

              value = option;
-             if (say_parse_prefix(&value, "identity=")) {
+             srv_str = say_parse_prefix(&value, "server=");
+             if (srv_str != NULL) {
+                     if (opts->addr_path != NULL ||
+                         opts->addr_type != NULL)
+                             goto duplicate;
+                     if (say_parse_prefix(&srv_str, "unix:")) {
+                             opts->addr_type = strdup("unix");
+                             opts->addr_path = srv_str;
+                     } else {
+                             srv_ptr = strdup(srv_str);
+                             srv_opt = srv_ptr;
+                             opts->addr_type = strsep(&srv_ptr,":");
+                             opts->addr_path = srv_ptr;

You don't need to allocate addr_path. Instead you can make it point to
the appropriate position in opts->copy and add '\0' at the end (it's
mutable). We do this in case of 'identity' AFAICS.

+                             free(srv_opt);
+                     }
+             } else if (say_parse_prefix(&value, "identity=")) {
                      if (opts->identity != NULL)
                              goto duplicate;
                      opts->identity = value;
diff --git a/src/say.h b/src/say.h
index ad3ba3417..6bee2cc90 100644
--- a/src/say.h
+++ b/src/say.h
@@ -162,6 +162,11 @@ struct log {
      int rotating_threads;
      enum syslog_facility syslog_facility;
      struct rlist in_log_list;
+     /* Server options. Either ip/port pair or unix socket address.*/
+     struct {
+             char *addr_type;
+             char *addr_path;
+     };

As I said above, I think you should turn addr_type into enum.
As for addr_path, there's log::path, which isn't used for socket
destination. You could reuse it instead of introducing a new
member.

};

/**
@@ -390,6 +395,8 @@ say_parse_logger_type(const char **str, enum
say_logger_type *type);

/** Syslog logger initialization params */
struct say_syslog_opts {
+     const char *addr_type;
+     const char *addr_path;
      const char *identity;
      enum syslog_facility facility;
      /* Input copy (content unspecified). */

References:
- [tarantool-patches] [PATCH 0/3] Syslog destination
  - From: Olga Arkhangelskaia
- [tarantool-patches] [PATCH 1/3] Configurable syslog destination
  - From: Olga Arkhangelskaia

[tarantool-patches] Re: [PATCH 1/3] Configurable syslog destination

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