Fix: kernel/ust snapshot backward compat for 2.10 relay

[lttng-tools.git] / src / bin / lttng-sessiond / consumer.c

diff --git a/src/bin/lttng-sessiond/consumer.c b/src/bin/lttng-sessiond/consumer.c
index d6a6e8cbd4b39e0027f1d9c6a32dbbb074472e6b..eeba2a2ab50eb5466b3b5b2aecd006eccbdfb7db 100644 (file)
--- a/src/bin/lttng-sessiond/consumer.c
+++ b/src/bin/lttng-sessiond/consumer.c
@@ -38,6 +38,62 @@
 #include "utils.h"
 #include "lttng-sessiond.h"
 
+/*
+ * Return allocated full pathname of the session using the consumer trace path
+ * and subdir if available.
+ *
+ * The caller can safely free(3) the returned value. On error, NULL is
+ * returned.
+ */
+char *setup_channel_trace_path(struct consumer_output *consumer,
+               const char *session_path)
+{
+       int ret;
+       char *pathname;
+
+       assert(consumer);
+       assert(session_path);
+
+       health_code_update();
+
+       /*
+        * Allocate the string ourself to make sure we never exceed
+        * LTTNG_PATH_MAX.
+        */
+       pathname = zmalloc(LTTNG_PATH_MAX);
+       if (!pathname) {
+               goto error;
+       }
+
+       /* Get correct path name destination */
+       if (consumer->type == CONSUMER_DST_NET &&
+                       consumer->relay_major_version == 2 &&
+                       consumer->relay_minor_version < 11) {
+               ret = snprintf(pathname, LTTNG_PATH_MAX, "%s%s/%s%s",
+                               consumer->dst.net.base_dir,
+                               consumer->chunk_path, consumer->domain_subdir,
+                               session_path);
+       } else {
+               ret = snprintf(pathname, LTTNG_PATH_MAX, "%s%s",
+                               consumer->domain_subdir, session_path);
+       }
+       DBG3("Consumer trace path relative to current trace chunk: \"%s\"",
+                       pathname);
+       if (ret < 0) {
+               PERROR("Failed to format channel path");
+               goto error;
+       } else if (ret >= LTTNG_PATH_MAX) {
+               ERR("Truncation occurred while formatting channel path");
+               ret = -1;
+               goto error;
+       }
+
+       return pathname;
+error:
+       free(pathname);
+       return NULL;
+}
+
 /*
  * Send a data payload using a given consumer socket of size len.
  *