Fix: relayd: live: read index file header

[lttng-tools.git] / src / common / index / index.c

diff --git a/src/common/index/index.c b/src/common/index/index.c
index 4df0d1b49116e8e177beb358e523f9dcca5f7c90..7c73dcfbd9e597def9249377348a462e6a86bd75 100644 (file)
--- a/src/common/index/index.c
+++ b/src/common/index/index.c
@@ -31,7 +31,7 @@
 
 #include "index.h"
 
-#define WRITE_FILE_FLAGS       O_WRONLY | O_CREAT | O_TRUNC
+#define WRITE_FILE_FLAGS       (O_WRONLY | O_CREAT | O_TRUNC)
 #define READ_ONLY_FILE_FLAGS   O_RDONLY
 
 static struct lttng_index_file *_lttng_index_file_create_from_trace_chunk(
@@ -49,8 +49,6 @@ static struct lttng_index_file *_lttng_index_file_create_from_trace_chunk(
        struct ctf_packet_index_file_hdr hdr;
        char index_directory_path[LTTNG_PATH_MAX];
        char index_file_path[LTTNG_PATH_MAX];
-       const uint32_t element_len = ctf_packet_index_len(index_major,
-                       index_minor);
        const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
        const bool acquired_reference = lttng_trace_chunk_get(chunk);
 
@@ -102,16 +100,46 @@ static struct lttng_index_file *_lttng_index_file_create_from_trace_chunk(
                goto error;
        }
 
-       ctf_packet_index_file_hdr_init(&hdr, index_major, index_minor);
-       size_ret = lttng_write(fd, &hdr, sizeof(hdr));
-       if (size_ret < sizeof(hdr)) {
-               PERROR("Failed to write index header");
-               goto error;
+       if (flags == WRITE_FILE_FLAGS) {
+               ctf_packet_index_file_hdr_init(&hdr, index_major, index_minor);
+               size_ret = lttng_write(fd, &hdr, sizeof(hdr));
+               if (size_ret < sizeof(hdr)) {
+                       PERROR("Failed to write index header");
+                       goto error;
+               }
+               index_file->element_len = ctf_packet_index_len(index_major, index_minor);
+       } else {
+               uint32_t element_len;
+
+               size_ret = lttng_read(fd, &hdr, sizeof(hdr));
+               if (size_ret < 0) {
+                       PERROR("Failed to read index header");
+                       goto error;
+               }
+               if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) {
+                       ERR("Invalid header magic");
+                       goto error;
+               }
+               if (index_major != be32toh(hdr.index_major)) {
+                       ERR("Index major number mismatch: %u, expect %u",
+                               be32toh(hdr.index_major), index_major);
+                       goto error;
+               }
+               if (index_minor != be32toh(hdr.index_minor)) {
+                       ERR("Index minor number mismatch: %u, expect %u",
+                               be32toh(hdr.index_minor), index_minor);
+                       goto error;
+               }
+               element_len = be32toh(hdr.packet_index_len);
+               if (element_len > sizeof(struct ctf_packet_index)) {
+                       ERR("Index element length too long");
+                       goto error;
+               }
+               index_file->element_len = element_len;
        }
        index_file->fd = fd;
        index_file->major = index_major;
        index_file->minor = index_minor;
-       index_file->element_len = element_len;
        urcu_ref_init(&index_file->ref);
 
        return index_file;