[PATCH 08/12] packet_size_breakdown(): refactor initialization

[Vitezslav Samel]

... using newly introduced struct psizetab.

Signed-off-by: Vitezslav Samel <vitezslav(a)samel.cz&gt;
---
 src/pktsize.c | 253 +++++++++++++++++++++++++++++++---------------------------
 1 file changed, 134 insertions(+), 119 deletions(-)

diff --git a/src/pktsize.c b/src/pktsize.c
index 4127b14..3a16454 100644
--- a/src/pktsize.c
+++ b/src/pktsize.c
@@ -31,6 +31,18 @@ struct ifstat_brackets {
 	unsigned long count;
 };
 
+struct psizetab {
+	WINDOW *win;
+	PANEL *panel;
+	WINDOW *borderwin;
+	PANEL *borderpanel;
+
+	struct ifstat_brackets brackets[20];
+	unsigned int interval;
+
+	int mtu;
+};
+
 static void rotate_size_log(int s __unused)
 {
 	rotate_flag = 1;
@@ -38,9 +50,8 @@ static void rotate_size_log(int s __unused)
 	signal(SIGUSR1, rotate_size_log);
 }
 
-static void write_size_log(struct ifstat_brackets *brackets,
-			   unsigned long nsecs, char *ifname, unsigned int mtu,
-			   FILE *logfile)
+static void write_size_log(struct psizetab *table, unsigned long nsecs,
+			   char *ifname, FILE *logfile)
 {
 	char atime[TIME_TARGET_MAX];
 	int i;
@@ -48,110 +59,140 @@ static void write_size_log(struct ifstat_brackets *brackets,
 	genatime(time(NULL), atime);
 	fprintf(logfile, "*** Packet Size Distribution, generated %s\n\n",
 		atime);
-	fprintf(logfile, "Interface: %s   MTU: %u\n\n", ifname, mtu);
+	fprintf(logfile, "Interface: %s   MTU: %u\n\n", ifname, table->mtu);
 	fprintf(logfile, "Packet Size (bytes)\tCount\n");
 
 	for (i = 0; i <= 19; i++) {
-		fprintf(logfile, "%u to %u:\t\t%lu\n", brackets[i].floor,
-			brackets[i].ceil, brackets[i].count);
+		fprintf(logfile, "%u to %u:\t\t%lu\n", table->brackets[i].floor,
+			table->brackets[i].ceil, table->brackets[i].count);
 	}
 	fprintf(logfile, "\nRunning time: %lu seconds\n", nsecs);
 	fflush(logfile);
 }
 
-static int initialize_brackets(struct ifstat_brackets *brackets,
-			       unsigned int *interval, int mtu,
-			       WINDOW *win)
+static void psizetab_init(struct psizetab *table, char *ifname)
+{
+	table->borderwin = newwin(LINES - 2, COLS, 1, 0);
+	table->borderpanel = new_panel(table->borderwin);
+
+	wattrset(table->borderwin, BOXATTR);
+	tx_box(table->borderwin, ACS_VLINE, ACS_HLINE);
+	mvwprintw(table->borderwin, 0, 1, " Packet Distribution by Size ");
+
+	table->win = newwin(LINES - 4, COLS - 2, 2, 1);
+	table->panel = new_panel(table->win);
+
+	tx_stdwinset(table->win);
+	wtimeout(table->win, -1);
+	wattrset(table->win, STDATTR);
+	tx_colorwin(table->win);
+
+	mvwprintw(table->win, 1, 1, "Packet size brackets for interface %s",
ifname);
+	wattrset(table->win, BOXATTR);
+	mvwprintw(table->win, 4, 1, "Packet Size (bytes)");
+	mvwprintw(table->win, 4, 26, "Count");
+	mvwprintw(table->win, 4, 36, "Packet Size (bytes)");
+	mvwprintw(table->win, 4, 60, "Count");
+	wattrset(table->win, HIGHATTR);
+
+	move(LINES - 1, 1);
+	stdexitkeyhelp();
+
+	update_panels();
+	doupdate();
+}
+
+static void psizetab_destroy(struct psizetab *table)
+{
+	del_panel(table->panel);
+	delwin(table->win);
+
+	del_panel(table->borderpanel);
+	delwin(table->borderwin);
+
+	update_panels();
+	doupdate();
+}
+
+static int initialize_brackets(struct psizetab *table)
 {
 	int i;
 
-	*interval = mtu / 20;	/* There are 20 packet size brackets */
+	table->interval = table->mtu / 20;	/* There are 20 packet size brackets */
 
 	for (i = 0; i <= 19; i++) {
-		brackets[i].floor = *interval * i + 1;
-		brackets[i].ceil = *interval * (i + 1);
-		brackets[i].count = 0;
+		table->brackets[i].floor = table->interval * i + 1;
+		table->brackets[i].ceil = table->interval * (i + 1);
+		table->brackets[i].count = 0;
 	}
 
-	brackets[19].ceil = mtu;
+	table->brackets[19].ceil = table->mtu;
 
 	for (i = 0; i <= 9; i++) {
-		wattrset(win, STDATTR);
-		mvwprintw(win, i + 5, 2, "%4u to %4u:", brackets[i].floor,
-			brackets[i].ceil);
-		wattrset(win, HIGHATTR);
-		mvwprintw(win, i + 5, 23, "%8lu", 0);
+		wattrset(table->win, STDATTR);
+		mvwprintw(table->win, i + 5, 2, "%4u to %4u:",
table->brackets[i].floor,
+			table->brackets[i].ceil);
+		wattrset(table->win, HIGHATTR);
+		mvwprintw(table->win, i + 5, 23, "%8lu", 0);
 	}
 
 	for (i = 10; i <= 19; i++) {
-		wattrset(win, STDATTR);
-		wmove(win, (i - 10) + 5, 36);
+		wattrset(table->win, STDATTR);
+		wmove(table->win, (i - 10) + 5, 36);
 
 		if (i != 19)
-			wprintw(win, "%4u to %4u:", brackets[i].floor,
-				brackets[i].ceil);
+			wprintw(table->win, "%4u to %4u:", table->brackets[i].floor,
+				table->brackets[i].ceil);
 		else
-			wprintw(win, "%4u to %4u+:", brackets[i].floor,
-				brackets[i].ceil);
+			wprintw(table->win, "%4u to %4u+:", table->brackets[i].floor,
+				table->brackets[i].ceil);
 
-		wattrset(win, HIGHATTR);
-		mvwprintw(win, (i - 10) + 5, 57, "%8lu", 0);
+		wattrset(table->win, HIGHATTR);
+		mvwprintw(table->win, (i - 10) + 5, 57, "%8lu", 0);
 	}
 
-	wattrset(win, STDATTR);
-	mvwprintw(win, 17, 1,
+	wattrset(table->win, STDATTR);
+	mvwprintw(table->win, 17, 1,
 		  "Interface MTU is %d bytes, not counting the data-link header",
-		  mtu);
-	mvwprintw(win, 18, 1,
+		  table->mtu);
+	mvwprintw(table->win, 18, 1,
 		  "Maximum packet size is the MTU plus the data-link header length");
-	mvwprintw(win, 19, 1,
+	mvwprintw(table->win, 19, 1,
 		  "Packet size computations include data-link headers, if any");
 
 	return 0;
 }
 
-static void update_size_distrib(unsigned int length,
-				struct ifstat_brackets *brackets,
-				unsigned int interval)
+static void update_size_distrib(struct psizetab *table, unsigned int length)
 {
 	unsigned int i;
 
-	i = (length - 1) / interval;	/* minus 1 to keep interval
-					   boundary lengths within the
-					   proper brackets */
+	i = (length - 1) / table->interval;	/* minus 1 to keep interval
+						   boundary lengths within the
+						   proper brackets */
 
 	if (i > 19)		/* This is for extras for MTU's not */
 		i = 19;		/* divisible by 20 */
 
-	brackets[i].count++;
+	table->brackets[i].count++;
 }
 
-static void print_size_distrib(struct ifstat_brackets *brackets, WINDOW *win)
+static void print_size_distrib(struct psizetab *table)
 {
 	for (unsigned int i = 0; i <= 19; i++) {
 		if (i < 10)
-			wmove(win, i + 5, 23);
+			wmove(table->win, i + 5, 23);
 		else
-			wmove(win, (i - 10) + 5, 57);
+			wmove(table->win, (i - 10) + 5, 57);
 
-		wprintw(win, "%8lu", brackets[i].count);
+		wprintw(table->win, "%8lu", table->brackets[i].count);
 	}
 }
 
 void packet_size_breakdown(char *ifname, time_t facilitytime)
 {
-	WINDOW *win;
-	PANEL *panel;
-	WINDOW *borderwin;
-	PANEL *borderpanel;
-
-	struct ifstat_brackets brackets[20];
-	unsigned int interval;
-
 	int ch;
 
-	int mtu;
-
 	int pkt_result;
 
 	struct timeval tv;
@@ -162,6 +203,8 @@ void packet_size_breakdown(char *ifname, time_t facilitytime)
 	int logging = options.logging;
 	FILE *logfile = NULL;
 
+	struct psizetab table;
+
 	int fd;
 
 	struct pkt_hdr pkt;
@@ -170,43 +213,34 @@ void packet_size_breakdown(char *ifname, time_t facilitytime)
 
 	if (!dev_up(ifname)) {
 		err_iface_down();
-		goto err_unmark;
-	}
-
-	mtu = dev_get_mtu(ifname);
-	if (mtu < 0) {
-		write_error("Unable to obtain interface MTU");
-		goto err_unmark;
+		return;
 	}
 
-	borderwin = newwin(LINES - 2, COLS, 1, 0);
-	borderpanel = new_panel(borderwin);
+	psizetab_init(&table, ifname);
 
-	wattrset(borderwin, BOXATTR);
-	tx_box(borderwin, ACS_VLINE, ACS_HLINE);
-	mvwprintw(borderwin, 0, 1, " Packet Distribution by Size ");
-
-	win = newwin(LINES - 4, COLS - 2, 2, 1);
-	panel = new_panel(win);
-
-	tx_stdwinset(win);
-	wtimeout(win, -1);
-	wattrset(win, STDATTR);
-	tx_colorwin(win);
-
-	move(LINES - 1, 1);
-	stdexitkeyhelp();
+	LIST_HEAD(promisc);
+	if (options.promisc) {
+		promisc_init(&promisc, ifname);
+		promisc_set_list(&promisc);
+	}
 
-	initialize_brackets(brackets, &interval, mtu, win);
+	fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
+	if(fd == -1) {
+		write_error("Unable to obtain monitoring socket");
+		goto err;
+	}
+	if(dev_bind_ifname(fd, ifname) == -1) {
+		write_error("Unable to bind interface on the socket");
+		goto err_close;
+	}
 
-	mvwprintw(win, 1, 1, "Packet size brackets for interface %s", ifname);
-	wattrset(win, BOXATTR);
+	table.mtu = dev_get_mtu(ifname);
+	if (table.mtu < 0) {
+		write_error("Unable to obtain interface MTU");
+		goto err_close;
+	}
 
-	mvwprintw(win, 4, 1, "Packet Size (bytes)");
-	mvwprintw(win, 4, 26, "Count");
-	mvwprintw(win, 4, 36, "Packet Size (bytes)");
-	mvwprintw(win, 4, 60, "Count");
-	wattrset(win, HIGHATTR);
+	initialize_brackets(&table);
 
 	if (logging) {
 		if (strcmp(current_logfile, "") == 0) {
@@ -232,35 +266,20 @@ void packet_size_breakdown(char *ifname, time_t facilitytime)
 			 "******** Packet size distribution facility started ********");
 	}
 
+	packet_init(&pkt);
+
 	exitloop = 0;
+
 	gettimeofday(&tv, NULL);
 	updtime = tv;
 	now = starttime = startlog = timeint = tv.tv_sec;
 
-	LIST_HEAD(promisc);
-	if (options.promisc) {
-		promisc_init(&promisc, ifname);
-		promisc_set_list(&promisc);
-	}
-
-	fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
-	if(fd == -1) {
-		write_error("Unable to obtain monitoring socket");
-		goto err;
-	}
-	if(dev_bind_ifname(fd, ifname) == -1) {
-		write_error("Unable to bind interface on the socket");
-		goto err_close;
-	}
-
-	packet_init(&pkt);
-
 	do {
 		gettimeofday(&tv, NULL);
 		now = tv.tv_sec;
 
 		if (screen_update_needed(&tv, &updtime)) {
-			print_size_distrib(brackets, win);
+			print_size_distrib(&table);
 
 			update_panels();
 			doupdate();
@@ -268,16 +287,16 @@ void packet_size_breakdown(char *ifname, time_t facilitytime)
 			updtime = tv;
 		}
 		if (now - timeint >= 5) {
-			printelapsedtime(now - starttime, 1, borderwin);
+			printelapsedtime(now - starttime, 1, table.borderwin);
 			dropped += packet_get_dropped(fd);
-			print_packet_drops(dropped, borderwin, 49);
+			print_packet_drops(dropped, table.borderwin, 49);
 			timeint = now;
 		}
 		if (logging) {
 			check_rotate_flag(&logfile);
 			if ((now - startlog) >= options.logspan) {
-				write_size_log(brackets, now - starttime,
-					       ifname, mtu, logfile);
+				write_size_log(&table, now - starttime,
+					       ifname, logfile);
 				startlog = now;
 			}
 		}
@@ -286,7 +305,7 @@ void packet_size_breakdown(char *ifname, time_t facilitytime)
 		    && (((now - starttime) / 60) >= facilitytime))
 			exitloop = 1;
 
-		if (packet_get(fd, &pkt, &ch, win) == -1) {
+		if (packet_get(fd, &pkt, &ch, table.win) == -1) {
 			write_error("Packet receive failed");
 			exitloop = 1;
 			break;
@@ -318,31 +337,27 @@ void packet_size_breakdown(char *ifname, time_t facilitytime)
 		if (pkt_result != PACKET_OK)
 			continue;
 
-		update_size_distrib(pkt.pkt_len, brackets, interval);
+		update_size_distrib(&table, pkt.pkt_len);
 	} while (!exitloop);
 
 	packet_destroy(&pkt);
 
-err_close:
-	close(fd);
-err:
 	if (logging) {
 		signal(SIGUSR1, SIG_DFL);
-		write_size_log(brackets, now - starttime, ifname, mtu, logfile);
+		write_size_log(&table, now - starttime, ifname, logfile);
 		writelog(logging, logfile,
 			 "******** Packet size distribution facility stopped ********");
 		fclose(logfile);
 	}
+	strcpy(current_logfile, "");
 
+err_close:
+	close(fd);
+err:
 	if (options.promisc) {
 		promisc_restore_list(&promisc);
 		promisc_destroy(&promisc);
 	}
 
-	del_panel(panel);
-	delwin(win);
-	del_panel(borderpanel);
-	delwin(borderwin);
-err_unmark:
-	strcpy(current_logfile, "");
+	psizetab_destroy(&table);
 }
-- 
1.9.1