iftop.c

/*
 * 工具箱中的某工具
 * 版权所有 2007-2015 PC GO Ld.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>

#define PROC_NET_DEV "/proc/net/dev"

#define MAX_IF 8		/* max interfaces we can handle */

#ifndef PAGE_SIZE
# define PAGE_SIZE 4096
#endif

#define _STR(s) #s
#define STR(s) _STR(s)

struct if_stats {
	char name[IFNAMSIZ];

	unsigned int mtu;

	unsigned int rx_bytes;
	unsigned int rx_packets;
	unsigned int rx_errors;
	unsigned int rx_dropped;

	unsigned int tx_bytes;
	unsigned int tx_packets;
	unsigned int tx_errors;
	unsigned int tx_dropped;
};

static int get_mtu(const char *if_name) {
	struct ifreq ifr;
	int s, ret;

	s = socket(AF_INET, SOCK_DGRAM, 0);
	if(s == -1) {
		perror("socket");
		exit(EXIT_FAILURE);
	}

	memset(&ifr, 0, sizeof(struct ifreq));
	ifr.ifr_addr.sa_family = AF_INET;
	strcpy(ifr.ifr_name, if_name);

	ret = ioctl(s, SIOCGIFMTU, &ifr);
	if(ret < 0) {
		perror("ioctl");
		exit(EXIT_FAILURE);
	}

	ret = close(s);
	if(ret < 0) {
		perror("close");
		exit(EXIT_FAILURE);
	}

	return ifr.ifr_mtu;
}

static int get_interfaces(struct if_stats *ifs) {
	char buf[PAGE_SIZE];
	char *p;
	int ret, nr, fd;

	fd = open(PROC_NET_DEV, O_RDONLY);
	if(fd == -1) {
		perror("open");
		exit(EXIT_FAILURE);
	}

	ret = read(fd, buf, sizeof(buf) - 1);
	if(ret < 0) {
		perror("read");
		exit(EXIT_FAILURE);
	} else if(!ret) {
		fprintf(stderr, "reading " PROC_NET_DEV " returned premature EOF\n");
		exit(EXIT_FAILURE);
	}
	buf[ret] = '\0';

	/* skip down to the third line */
	p = strchr(buf, '\n');
	if(!p) {
		fprintf(stderr, "parsing " PROC_NET_DEV " failed unexpectedly\n");
		exit(EXIT_FAILURE);
	}
	p = strchr(p + 1, '\n');
	if(!p) {
		fprintf(stderr, "parsing " PROC_NET_DEV " failed unexpectedly\n");
		exit(EXIT_FAILURE);
	}
	p += 1;

	/*
	 * Key:
	 * if: (Rx) bytes packets errs drop fifo frame compressed multicast \
	 *     (Tx) bytes packets errs drop fifo colls carrier compressed
	 */
	for(nr = 0; nr < MAX_IF; nr++) {
		char *c;

		ret = sscanf(p, "%" STR(IFNAMSIZ) "s", ifs->name);
		if(ret != 1) {
			fprintf(stderr, "parsing " PROC_NET_DEV " failed unexpectedly\n");
			exit(EXIT_FAILURE);
		}

		/*
		 * This works around a bug in the proc file where large interface names
		 * or Rx byte counts eat the delimiter, breaking sscanf.
		 */
		c = strchr(ifs->name, ':');
		if(c) *c = 0;

		p = strchr(p, ':') + 1;

		ret = sscanf(p, "%u %u %u %u %*u %*u %*u %*u %u %u %u %u %*u %*u "
				"%*u %*u\n", &ifs->rx_bytes, &ifs->rx_packets,
				&ifs->rx_errors, &ifs->rx_dropped, &ifs->tx_bytes,
				&ifs->tx_packets, &ifs->tx_errors, &ifs->tx_dropped);
		if(ret != 8) {
			fprintf(stderr, "parsing " PROC_NET_DEV " failed unexpectedly\n");
			exit(EXIT_FAILURE);
		}

		ifs->mtu = get_mtu(ifs->name);

		p = strchr(p, '\n') + 1;
		if(*p == '\0') {
			nr++;
			break;
		}

		ifs++;
	}

	ret = close(fd);
	if(ret) {
		perror("close");
		exit(EXIT_FAILURE);
	}

	return nr;
}

static void print_header(void) {
	printf("               Rx                              Tx\n");
	printf("%-8s %-5s %-10s %-8s %-5s %-5s %-10s %-8s %-5s %-5s\n",
			"name", "MTU", "bytes", "packets", "errs", "drpd", "bytes",
			"packets", "errs", "drpd");
}

static int print_interfaces(struct if_stats *old, struct if_stats *new, int nr) {
	int i = 0;

	while(nr--) {
		if(old->rx_packets || old->tx_packets) {
			printf("%-8s %-5u %-10u %-8u %-5u %-5u %-10u %-8u %-5u %-5u\n",
					new->name, new->mtu,
					new->rx_bytes - old->rx_bytes,
					new->rx_packets - old->rx_packets,
					new->rx_errors - old->rx_errors,
					new->rx_dropped - old->rx_dropped,
					new->tx_bytes - old->tx_bytes,
					new->tx_packets - old->tx_packets,
					new->tx_errors - old->tx_errors,
					new->tx_dropped - old->tx_dropped);
			i++;
		}
		old++;
		new++;
	}

	return i;
}

static void usage(const char *name) {
	fprintf(stderr, "Usage: %s [ -r <repeats>] [ -d <delay>]\n", name);
}

int main(int argc, char *argv[]) {
	struct if_stats ifs[2][MAX_IF];
	int count = 0, header_interval = 22, delay = 1, i;
	unsigned int toggle = 0;

	for(i = 1; i < argc; i++) {
		if(strcmp(argv[i], "-d") == 0) {
			if(i >= argc - 1) {
				fprintf(stderr, "Option -d requires an argument.\n");
				exit(EXIT_FAILURE);
			}
			delay = atoi(argv[i++]);
			if(!delay) delay = 1;
			continue;
		}
		if(strcmp(argv[i], "-r") == 0) {
			if (i >= argc - 1) {
				fprintf(stderr, "Option -r requires an argument.\n");
				exit(EXIT_FAILURE);
			}
			header_interval = atoi(argv[i++]);
			if(header_interval < MAX_IF) header_interval = MAX_IF;
			continue;
		}
		if(strcmp(argv[i], "-h") == 0) {
			usage(argv[0]);
			//exit(EXIT_SUCCESS);
			return EXIT_SUCCESS;
		}
		usage(argv[0]);
		//exit(EXIT_FAILURE);
		return EXIT_FAILURE;
	}

	get_interfaces(ifs[!toggle]);
	if(header_interval) print_header();
	while(1) {
		int nr;

		sleep(delay);
		nr = get_interfaces(ifs[toggle]);
		if(header_interval && count + nr > header_interval) {
			print_header();
			count = 0;
		}
		count += print_interfaces(ifs[!toggle], ifs[toggle], nr);
		toggle = !toggle;
	}

	return 0;
}