From a55111610a296f69b9e066c59a9f3bc16f1f542a Mon Sep 17 00:00:00 2001 From: Anders Broman Date: Thu, 3 Jan 2019 15:51:56 +0100 Subject: [PATCH] Dumpcap: Set a bigger IO buffer (64KiB). Set a bigger IO buffer to avoid syscall overhead. See https://github.com/the-tcpdump-group/libpcap/issues/792 Change-Id: If370da5ab2b70a9d0c925dd7c4c5c135c675c3f6 Reviewed-on: https://code.wireshark.org/review/31326 Petri-Dish: Anders Broman Tested-by: Petri Dish Buildbot Reviewed-by: Guy Harris Reviewed-by: Anders Broman --- dumpcap.c | 29 +++++++++++++++++++++++++++-- ringbuffer.c | 40 ++++++++++++++++++++++++++++++++-------- wsutil/file_util.h | 3 +++ 3 files changed, 62 insertions(+), 10 deletions(-) diff --git a/dumpcap.c b/dumpcap.c index 8849ac9b55..7db3ded813 100644 --- a/dumpcap.c +++ b/dumpcap.c @@ -306,6 +306,7 @@ typedef struct _loop_data { /* output file(s) */ FILE *pdh; int save_file_fd; + char *io_buffer; /**< Our IO buffer if we increase the size from the standard size */ guint64 bytes_written; /**< Bytes written for the current file. */ /* autostop conditions */ int packets_written; /**< Packets written for the current file. */ @@ -3189,6 +3190,21 @@ capture_loop_init_output(capture_options *capture_opts, loop_data *ld, char *err ld->pdh = ws_fdopen(ld->save_file_fd, "wb"); if (ld->pdh == NULL) { err = errno; + } else { + size_t buffsize = IO_BUF_SIZE; +#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE + ws_statb64 statb; + + if (ws_fstat64(ld->save_file_fd, &statb) == 0) { + if (statb.st_blksize > IO_BUF_SIZE) { + buffsize = statb.st_blksize; + } + } +#endif + /* Increase the size of the IO buffer */ + ld->io_buffer = (char *)g_malloc(buffsize); + setvbuf(ld->pdh, ld->io_buffer, _IOFBF, buffsize); + g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_init_output: buffsize %zu", buffsize); } } if (ld->pdh) { @@ -3208,6 +3224,8 @@ capture_loop_init_output(capture_options *capture_opts, loop_data *ld, char *err if (!successful) { fclose(ld->pdh); ld->pdh = NULL; + g_free(ld->io_buffer); + ld->io_buffer = NULL; } } @@ -3244,6 +3262,7 @@ capture_loop_close_output(capture_options *capture_opts, loop_data *ld, int *err unsigned int i; capture_src *pcap_src; guint64 end_time = create_timestamp(); + gboolean success; g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_close_output"); @@ -3280,10 +3299,13 @@ capture_loop_close_output(capture_options *capture_opts, loop_data *ld, int *err if (err_close != NULL) { *err_close = errno; } - return (FALSE); + success = FALSE; } else { - return (TRUE); + success = TRUE; } + g_free(ld->io_buffer); + ld->io_buffer = NULL; + return success; } } @@ -3722,6 +3744,8 @@ do_file_switch_or_stop(capture_options *capture_opts) fclose(global_ld.pdh); global_ld.pdh = NULL; global_ld.go = FALSE; + g_free(global_ld.io_buffer); + global_ld.io_buffer = NULL; return FALSE; } if (global_ld.file_duration_timer) { @@ -3846,6 +3870,7 @@ capture_loop_start(capture_options *capture_opts, gboolean *stats_known, struct global_ld.err = 0; /* no error seen yet */ global_ld.pdh = NULL; global_ld.save_file_fd = -1; + global_ld.io_buffer = NULL; global_ld.file_count = 0; global_ld.file_duration_timer = NULL; global_ld.next_interval_time = 0; diff --git a/ringbuffer.c b/ringbuffer.c index b84c032086..1251ed3057 100644 --- a/ringbuffer.c +++ b/ringbuffer.c @@ -50,18 +50,19 @@ typedef struct _rb_file { gchar *name; } rb_file; -/* Ringbuffer data structure */ +/** Ringbuffer data structure */ typedef struct _ringbuf_data { rb_file *files; - guint num_files; /* Number of ringbuffer files (1 to ...) */ - guint curr_file_num; /* Number of the current file (ever increasing) */ - gchar *fprefix; /* Filename prefix */ - gchar *fsuffix; /* Filename suffix */ - gboolean unlimited; /* TRUE if unlimited number of files */ + guint num_files; /**< Number of ringbuffer files (1 to ...) */ + guint curr_file_num; /**< Number of the current file (ever increasing) */ + gchar *fprefix; /**< Filename prefix */ + gchar *fsuffix; /**< Filename suffix */ + gboolean unlimited; /**< TRUE if unlimited number of files */ - int fd; /* Current ringbuffer file descriptor */ + int fd; /**< Current ringbuffer file descriptor */ FILE *pdh; - gboolean group_read_access; /* TRUE if files need to be opened with group read access */ + char *io_buffer; /**< The IO buffer used to write to the file */ + gboolean group_read_access; /**< TRUE if files need to be opened with group read access */ } ringbuf_data; static ringbuf_data rb_data; @@ -229,7 +230,22 @@ ringbuf_init_libpcap_fdopen(int *err) if (err != NULL) { *err = errno; } + } else { + size_t buffsize = IO_BUF_SIZE; +#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE + ws_statb64 statb; + + if (ws_fstat64(rb_data.fd, &statb) == 0) { + if (statb.st_blksize > IO_BUF_SIZE) { + buffsize = statb.st_blksize; + } + } +#endif + /* Increase the size of the IO bubffer */ + rb_data.io_buffer = (char *)g_malloc(buffsize); + setvbuf(rb_data.pdh, rb_data.io_buffer, _IOFBF, buffsize); } + return rb_data.pdh; } @@ -251,6 +267,8 @@ ringbuf_switch_file(FILE **pdh, gchar **save_file, int *save_file_fd, int *err) ws_close(rb_data.fd); /* XXX - the above should have closed this already */ rb_data.pdh = NULL; /* it's still closed, we just got an error while closing */ rb_data.fd = -1; + g_free(rb_data.io_buffer); + rb_data.io_buffer = NULL; return FALSE; } @@ -298,6 +316,9 @@ ringbuf_libpcap_dump_close(gchar **save_file, int *err) } rb_data.pdh = NULL; rb_data.fd = -1; + g_free(rb_data.io_buffer); + rb_data.io_buffer = NULL; + } /* set the save file name to the current file */ @@ -362,6 +383,9 @@ ringbuf_error_cleanup(void) } } } + g_free(rb_data.io_buffer); + rb_data.io_buffer = NULL; + /* free the memory */ ringbuf_free(); } diff --git a/wsutil/file_util.h b/wsutil/file_util.h index 435bacd0f3..565b9d46e3 100644 --- a/wsutil/file_util.h +++ b/wsutil/file_util.h @@ -36,6 +36,9 @@ extern "C" { #include /* for stat() and struct stat */ +/* We set a larger IO Buffer size for the capture files */ +#define IO_BUF_SIZE (64 * 1024) + /* * Visual C++ on Win32 systems doesn't define these. (Old UNIX systems don't * define them either.)