propagator/probing.c

/*
 * Guillaume Cottenceau (gc@mandrakesoft.com)
 *
 * Copyright 2000 MandrakeSoft
 *
 * This software may be freely redistributed under the terms of the GNU
 * public license.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
 * Portions from Erik Troan (ewt@redhat.com)
 *
 * Copyright 1996 Red Hat Software
 *
 */


/*
 * This contains stuff related to probing:
 * (1) any (actually only SCSI, NET, CPQ, USB Controllers) devices (autoprobe for PCI and USB)
 * (2) IDE media
 * (3) SCSI media
 * (4) ETH devices
 */


#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <dirent.h>
#include "stage1.h"

#include "log.h"
#include "frontend.h"
#include "modules.h"
#include "probing.h"

struct media_info {
	char * name;
	char * model;
	enum media_type type;
};

#ifndef DISABLE_NETWORK
struct net_description_elem
{
	char * intf_name;
	char * intf_description;
};
static char * net_dev_black_list[] = {"lo", "wlan", /* add what you need here! */ NULL};
static struct net_description_elem net_descriptions[50];
static int net_descr_number = 0;
static char * intf_descr_for_discover = NULL;
static char * net_intf_too_early_name[50]; /* for modules providing more than one net intf */
static int net_intf_too_early_number = 0;
static int net_intf_too_early_ptr = 0;

void net_discovered_interface(char * intf_name)
{
	if (!intf_descr_for_discover) {
		net_intf_too_early_name[net_intf_too_early_number++] = strdup(intf_name);
		return;
	}
	if (!intf_name) {
		if (net_intf_too_early_ptr >= net_intf_too_early_number) {
			log_message("NET: was expecting another network interface (broken net module?)");
			return;
		}
		net_descriptions[net_descr_number].intf_name = net_intf_too_early_name[net_intf_too_early_ptr++];
	}
	else
		net_descriptions[net_descr_number].intf_name = strdup(intf_name);
	net_descriptions[net_descr_number].intf_description = strdup(intf_descr_for_discover);
	intf_descr_for_discover = NULL;
	net_descr_number++;
}

char * get_net_intf_description(char * intf_name)
{
	char dev[SYSFS_PATH_MAX];
	char drv[SYSFS_PATH_MAX];
	ssize_t i;

	snprintf(dev, SYSFS_PATH_MAX, "/sys/class/net/%s/device/driver", intf_name);
	if ((i = readlink(dev, drv, SYSFS_PATH_MAX)) > 0) {
		drv[i] = '\0';
		return strdup(strrchr(drv, '/') + 1);
	} else {
		return strdup("unknown");
	}
}
#endif

#ifndef DISABLE_MEDIAS
static struct media_info * medias = NULL;

static int usb_not_there(void)
{
	DIR *dir = opendir("/sys/module/usb_storage");
	if (dir) closedir(dir);
	return !dir;
}

static void find_media(void)
{
	FILE *f;
	DIR *dir = NULL;
	struct dirent *dirent = NULL;
	struct stat st;
	struct media_info tmp[50];
	char path[SYSFS_PATH_MAX];
	char buf[512];
	char *s;
	int i = 0, count = 0;

	if (medias)
		free(medias); /* that does not free the strings, by the way */

	log_message("checking for /sys/module/usb_storage directory");
	if (usb_not_there()) {
		wait_message("Waiting for USB storage devices to show up...");
		my_insmod("usb_storage", NULL);
		my_insmod("sd_mod", NULL);
		my_insmod("uas", NULL);
		while (usb_not_there() && (i < 10)) {
			sleep(1);
			i++;
		}
		remove_wait_message();
	}

	if ((dir = opendir("/sys/block")) == NULL) {
		log_message("failed to open /sys/block directory");
		return;
	}

	while ((dirent = readdir(dir)) != NULL) {
		if (!strcmp(dirent->d_name, ".") ||
			!strcmp(dirent->d_name, "..")) continue;

		memset(path, 0, SYSFS_PATH_MAX);
		strcpy(path, "/sys/block/");
		strcat(path, dirent->d_name);
		s = path + strlen(path);

		/* probe for scsi type */
		strcat(path, "/device/type");
		if (lstat(path, &st) == 0 && S_ISREG(st.st_mode)) {
			tmp[count].name = strdup(dirent->d_name);
			tmp[count].type = UNKNOWN_MEDIA;
			if ((f = fopen(path, "r")) != NULL) {
				int type = SCSI_TYPE_DISK;
				if (fgets(buf, sizeof(buf), f) > 0) {
					if (!strncmp(buf, "MMC", 3) || !strncmp(buf, "SD", 2))
					    tmp[count].type = DISK;
					else if (sscanf(buf, "%d", &type) > 0) {
						if (type == SCSI_TYPE_DISK) tmp[count].type = DISK;
						else if (type == SCSI_TYPE_ROM) tmp[count].type = CDROM;
						else if (type == SCSI_TYPE_TAPE) tmp[count].type = TAPE;
					}
				}
				fclose(f);
			}

			*s = 0;
			strcat(path, "/device/model");
			if ((f = fopen(path, "r")) != NULL) {
				if (fgets(buf, sizeof(buf), f)) {
					if(buf[strlen(buf)-1] == '\n')
						buf[strlen(buf)-1] = 0;
					tmp[count].model = strdup(buf);
				}
				fclose(f);
			} else {
				tmp[count].model = strdup("(unknown)");
			}

			log_message("SCSI/%d: %s is a %s", tmp[count].type, tmp[count].name, tmp[count].model);
			count++;
			continue;
		}

		/* assume ide */
		*s = 0;
		strcat(s, "/device/media");
		if (lstat(path, &st) == 0 && S_ISREG(st.st_mode)) {
			tmp[count].name = strdup(dirent->d_name);
			tmp[count].type = UNKNOWN_MEDIA;
			if ((f = fopen(path, "r")) != NULL) {
				if (fgets(buf, sizeof(buf), f)) {
					if (!strncmp("disk", buf, 4))
						tmp[count].type = DISK;
					else if (!strncmp("cdrom", buf, 5))
						tmp[count].type = CDROM;
					else if (!strncmp("tape", buf, 4))
						tmp[count].type = TAPE;
					else if (!strncmp("floppy", buf, 6))
						tmp[count].type = FLOPPY;
				}
				fclose(f);
			}

			/* grab model */
			strcpy(path, "/proc/ide/");
			strcat(path, dirent->d_name);
			strcat(path, "/model");
			if ((f = fopen(path, "r")) != NULL) {
				if (fgets(buf, sizeof(buf), f)) {
					if(buf[strlen(buf)-1] == '\n')
						buf[strlen(buf)-1] = 0;
					tmp[count].model = strdup(buf);
				}
				fclose(f);
			} else {
				tmp[count].model = strdup("(none)");
			}
			log_message("IDE/%d: %s is a %s", tmp[count].type, tmp[count].name, tmp[count].model);
			count++;
		}
	}

	closedir(dir);

	tmp[count].name = NULL;
	count++;
	medias = memdup(tmp, sizeof(struct media_info) * count);
}

/* Finds by media */
void get_medias(enum media_type media, char *** names, char *** models)
{
	struct media_info * m;
	char * tmp_names[250];
	char * tmp_models[250];
	int count;

	find_media();

	m = medias;

	count = 0;
	while (m && m->name) {
		/* detect hybrid iso images (those dumped to a USB stick) */
		if ((m->type == media) || ((media == CDROM) && (m->type == DISK))) {
			tmp_names[count] = strdup(m->name);
			tmp_models[count++] = strdup(m->model);
		}
		m++;
	}
	tmp_names[count] = NULL;
	tmp_models[count++] = NULL;

	*names = memdup(tmp_names, sizeof(char *) * count);
	*models = memdup(tmp_models, sizeof(char *) * count);
}
#endif /* DISABLE_MEDIAS */

#ifndef DISABLE_NETWORK

static int net_device_has_carrier(const char *device) {
	int fd = -1;
	char *p = NULL;
	int ret = 0;
	char state = '\0';
	if (asprintf(&p, "/sys/class/net/%s/carrier", device) == -1) {
		log_message("net_device_has_carrier: OOM");
		return 0;
	}
	fd = open(p, O_RDONLY);
	if (fd < 0) {
		log_perror("net_device_has_carrier: failed to open sysfs knob");
		goto out;
	}
	if (read(fd, &state, 1) != 1) {
		log_perror("net_device_has_carrier: failed to read sysfs knob");
		goto out;
	}
	ret = !!(state == '1');
out:
	if (p) {
		free(p);
		p = NULL;
	}
	if (fd >= 0) {
		close(fd);
		fd = -1;
	}
	return ret;
}

static int net_device_available(char * device)
{
	struct ifreq req;
	int s;

	s = socket(AF_INET, SOCK_DGRAM, 0);
	if (s < 0) {
		log_perror(device);
		return 0;
	}
	strcpy(req.ifr_name, device);
	if (ioctl(s, SIOCGIFFLAGS, &req)) {
		/* if we can't get the flags, the networking device isn't available */
		close(s);
		return 0;
	}
	if (!(req.ifr_flags & IFF_UP)) {
		req.ifr_flags |= IFF_UP;
		if (ioctl(s, SIOCSIFFLAGS, &req)) {
			log_perror("ifup");
			/* skip the interface we can't bring up */
		}
		/* XXX: we want to report only interfaces with carrier as available.
		 * However calling net_device_has_carrier right after ifup is useless:
		 * the kernel needs some time to figure out if the carrier is present.
		 * Therefore report that this interface is *not* available.
		 * intf_select_and_up will wait a second and retry if necessary
		 * (i.e. no interfaces with carrier have been found), and on the next
		 * attempt `device` will be already up, and we'll check if `device`
		 * has the carrier.
		 *
		 * Sounds a bit tricky? A simple solution is to put sleep(1) after
		 * ifup, but there might be quite a number of interfaces (I've got
		 * boards with 4 and 6 Ethernets), and sleeping for O(N) seconds
		 * for no good reason might be annoying.
		 * Oh, alternatively we could setup a full-fledged event loop and
		 * wait for netlink notifications, but that's too much code and
		 * *complexity*.
		 */
		close(s);
		return 0;
	}
	/* `device` was already up (perhaps we've brought it up during
	 * previous calls), check if it has the carrier
	 */
	close(s);
	return net_device_has_carrier(device);
}


char ** get_net_devices(void)
{
	DIR * sys_net;
	char * tmp[50] = {NULL};
	struct dirent * ent;
	int drop, j, i = 0;

	sys_net = opendir("/sys/class/net");
	if (sys_net == NULL)
		return memdup(tmp, sizeof(tmp[0]));
	while ((ent = readdir(sys_net)) != NULL)
	{
		/* check interface name in black list */
		for (drop=j=0; net_dev_black_list[j] != NULL; j++)
			if (strncmp(ent->d_name, net_dev_black_list[j], strlen(net_dev_black_list[j])) == 0) {
				drop = -1;
				break;
			}
		if (!drop && net_device_available(ent->d_name)) {
			tmp[i++] = strdup(ent->d_name);
		}
	}
	tmp[i++] = NULL;
	closedir(sys_net);

	return memdup(tmp, sizeof(tmp[0]) * i);
}


/* reverse for get_net_devices() to avoid memory leaks */
void free_net_devices(char ** list)
{
	char ** item;

	for (item = list; *item; item++) {
		free(*item);
		*item = NULL;
	}
	free(list);
}
#endif /* DISABLE_NETWORK */