Roman Mashak reported that ss currently shows no output when it
should continuously report information about terminated sockets
(-E, --events switch).
This happens because I missed this case in 691bd854bf4a ("ss:
Buffer raw fields first, then render them as a table") and the
rendering function is simply not called.
To fix this, we need to:
- call render() every time we need to display new socket events
from generic_show_sock(), which is only used to follow events.
Always call it even if specific socket display functions
return errors to ensure we clean up buffers
- get the screen width every time we have new events to display,
thus factor out getting the screen width from main() into a
function we'll call whenever we calculate columns width
- reset the current field pointer after rendering, more output
might come after render() is called
Reported-by: Roman Mashak <m...@mojatatu.com>
Fixes: 691bd854bf4a ("ss: Buffer raw fields first, then render them as a table")
Signed-off-by: Stefano Brivio <sbri...@redhat.com>
---
misc/ss.c | 61 ++++++++++++++++++++++++++++++++++++++++---------------------
1 file changed, 40 insertions(+), 21 deletions(-)
diff --git a/misc/ss.c b/misc/ss.c
index e087bef739b0..6338820bf4a0 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -1106,15 +1106,33 @@ static void buf_free_all(void)
buffer.head = NULL;
}
+/* Get current screen width, default to 80 columns if TIOCGWINSZ fails */
+static int render_screen_width(void)
+{
+ int width = 80;
+
+ if (isatty(STDOUT_FILENO)) {
+ struct winsize w;
+
+ if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &w) != -1) {
+ if (w.ws_col > 0)
+ width = w.ws_col;
+ }
+ }
+
+ return width;
+}
+
/* Calculate column width from contents length. If columns don't fit on one
* line, break them into the least possible amount of lines and keep them
* aligned across lines. Available screen space is equally spread between
fields
* as additional spacing.
*/
-static void render_calc_width(int screen_width)
+static void render_calc_width(void)
{
- int first, len = 0, linecols = 0;
+ int screen_width = render_screen_width();
struct column *c, *eol = columns - 1;
+ int first, len = 0, linecols = 0;
/* First pass: set width for each column to measured content length */
for (first = 1, c = columns; c - columns < COL_MAX; c++) {
@@ -1195,7 +1213,7 @@ newline:
}
/* Render buffered output with spacing and delimiters, then free up buffers */
-static void render(int screen_width)
+static void render(void)
{
struct buf_token *token;
int printed, line_started = 0;
@@ -1209,7 +1227,7 @@ static void render(int screen_width)
/* Ensure end alignment of last token, it wasn't necessarily flushed */
buffer.tail->end += buffer.cur->len % 2;
- render_calc_width(screen_width);
+ render_calc_width();
/* Rewind and replay */
buffer.tail = buffer.head;
@@ -1245,6 +1263,7 @@ static void render(int screen_width)
}
buf_free_all();
+ current_field = columns;
}
static void sock_state_print(struct sockstat *s)
@@ -4264,23 +4283,33 @@ static int generic_show_sock(const struct sockaddr_nl
*addr,
{
struct sock_diag_msg *r = NLMSG_DATA(nlh);
struct inet_diag_arg inet_arg = { .f = arg, .protocol = IPPROTO_MAX };
+ int ret;
switch (r->sdiag_family) {
case AF_INET:
case AF_INET6:
inet_arg.rth = inet_arg.f->rth_for_killing;
- return show_one_inet_sock(addr, nlh, &inet_arg);
+ ret = show_one_inet_sock(addr, nlh, &inet_arg);
+ break;
case AF_UNIX:
- return unix_show_sock(addr, nlh, arg);
+ ret = unix_show_sock(addr, nlh, arg);
+ break;
case AF_PACKET:
- return packet_show_sock(addr, nlh, arg);
+ ret = packet_show_sock(addr, nlh, arg);
+ break;
case AF_NETLINK:
- return netlink_show_sock(addr, nlh, arg);
+ ret = netlink_show_sock(addr, nlh, arg);
+ break;
case AF_VSOCK:
- return vsock_show_sock(addr, nlh, arg);
+ ret = vsock_show_sock(addr, nlh, arg);
+ break;
default:
- return -1;
+ ret = -1;
}
+
+ render();
+
+ return ret;
}
static int handle_follow_request(struct filter *f)
@@ -4647,7 +4676,6 @@ int main(int argc, char *argv[])
FILE *filter_fp = NULL;
int ch;
int state_filter = 0;
- int screen_width = 80;
while ((ch = getopt_long(argc, argv,
"dhaletuwxnro460spbEf:miA:D:F:vVzZN:KHS",
@@ -4949,15 +4977,6 @@ int main(int argc, char *argv[])
if (!(current_filter.states & (current_filter.states - 1)))
columns[COL_STATE].disabled = 1;
- if (isatty(STDOUT_FILENO)) {
- struct winsize w;
-
- if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &w) != -1) {
- if (w.ws_col > 0)
- screen_width = w.ws_col;
- }
- }
-
if (show_header)
print_header();
@@ -4988,7 +5007,7 @@ int main(int argc, char *argv[])
if (show_users || show_proc_ctx || show_sock_ctx)
user_ent_destroy();
- render(screen_width);
+ render();
return 0;
}
--
2.15.1
