chiark / gitweb /
[PATCH] udev - safer string handling - part two
[elogind.git] / namedev.c
index f138fe976955fe99bb3c24318acb132369619c1b..f688507dc39c985b389e3b1c68cf2efafce110f3 100644 (file)
--- a/namedev.c
+++ b/namedev.c
 #include <sys/wait.h>
 #include <sys/stat.h>
 
+#include "libsysfs/sysfs/libsysfs.h"
 #include "list.h"
 #include "udev.h"
 #include "udev_version.h"
 #include "logging.h"
 #include "namedev.h"
-#include "libsysfs/libsysfs.h"
 #include "klibc_fixups.h"
 
+static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr);
+
 LIST_HEAD(config_device_list);
 LIST_HEAD(perm_device_list);
 
@@ -155,7 +157,7 @@ static mode_t get_default_mode(void)
 static char *get_default_owner(void)
 {
        if (strlen(default_owner_str) == 0)
-               strncpy(default_owner_str, "root", OWNER_SIZE);
+               strfieldcpy(default_owner_str, "root");
 
        return default_owner_str;
 }
@@ -163,12 +165,53 @@ static char *get_default_owner(void)
 static char *get_default_group(void)
 {
        if (strlen(default_group_str) == 0)
-               strncpy(default_group_str, "root", GROUP_SIZE);
+               strfieldcpy(default_group_str, "root");
 
        return default_group_str;
 }
 
-static void apply_format(struct udevice *udev, unsigned char *string)
+/* extract possible {attr} and move str behind it */
+static char *get_format_attribute(char **str)
+{
+       char *pos;
+       char *attr = NULL;
+
+       if (*str[0] == '{') {
+               pos = strchr(*str, '}');
+               if (pos == NULL) {
+                       dbg("missing closing brace for format");
+                       return NULL;
+               }
+               pos[0] = '\0';
+               attr = *str+1;
+               *str = pos+1;
+               dbg("attribute='%s', str='%s'", attr, *str);
+       }
+       return attr;
+}
+
+/* extract possible format length and move str behind it*/
+static int get_format_len(char **str)
+{
+       int num;
+       char *tail;
+
+       if (isdigit(*str[0])) {
+               num = (int) strtoul(*str, &tail, 10);
+               if (tail != NULL) {
+                       *str = tail;
+                       dbg("format length=%i", num);
+                       return num;
+               } else {
+                       dbg("format parsing error '%s'", *str);
+               }
+       }
+       return -1;
+}
+
+static void apply_format(struct udevice *udev, char *string, size_t maxsize,
+                        struct sysfs_class_device *class_dev,
+                        struct sysfs_device *sysfs_device)
 {
        char temp[NAME_SIZE];
        char temp1[NAME_SIZE];
@@ -176,87 +219,105 @@ static void apply_format(struct udevice *udev, unsigned char *string)
        char *pos;
        char *pos2;
        char *pos3;
+       char *attr;
        int num;
+       int i;
+       char c;
+       struct sysfs_attribute *tmpattr;
 
        pos = string;
+
        while (1) {
-               num = 0;
                pos = strchr(pos, '%');
-
-               if (pos) {
+               if (pos != NULL) {
                        pos[0] = '\0';
                        tail = pos+1;
-                       if (isdigit(tail[0])) {
-                               num = (int) strtoul(&pos[1], &tail, 10);
-                               if (tail == NULL) {
-                                       dbg("format parsing error '%s'", pos+1);
-                                       break;
-                               }
-                       }
+                       num = get_format_len(&tail);
+                       c = tail[0];
                        strfieldcpy(temp, tail+1);
+                       tail = temp;
+               } else {
+                       break;
+               }
+               dbg("format=%c, string='%s', tail='%s'",c , string, tail);
 
-                       switch (tail[0]) {
-                       case 'b':
-                               if (strlen(udev->bus_id) == 0)
-                                       break;
-                               strcat(pos, udev->bus_id);
-                               dbg("substitute bus_id '%s'", udev->bus_id);
+               attr = get_format_attribute(&tail);
+
+               switch (c) {
+               case 'b':
+                       if (strlen(udev->bus_id) == 0)
                                break;
-                       case 'k':
-                               if (strlen(udev->kernel_name) == 0)
-                                       break;
-                               strcat(pos, udev->kernel_name);
-                               dbg("substitute kernel name '%s'", udev->kernel_name);
+                       strnfieldcat(pos, udev->bus_id, maxsize);
+                       dbg("substitute bus_id '%s'", udev->bus_id);
+                       break;
+               case 'k':
+                       if (strlen(udev->kernel_name) == 0)
                                break;
-                       case 'n':
-                               if (strlen(udev->kernel_number) == 0)
-                                       break;
-                               strcat(pos, udev->kernel_number);
-                               dbg("substitute kernel number '%s'", udev->kernel_number);
+                       strnfieldcat(pos, udev->kernel_name, maxsize);
+                       dbg("substitute kernel name '%s'", udev->kernel_name);
+                       break;
+               case 'n':
+                       if (strlen(udev->kernel_number) == 0)
                                break;
-                       case 'm':
-                               sprintf(pos, "%u", udev->minor);
-                               dbg("substitute minor number '%u'", udev->minor);
+                       strnfieldcat(pos, udev->kernel_number, maxsize);
+                       dbg("substitute kernel number '%s'", udev->kernel_number);
                                break;
+               case 'm':
+                       sprintf(pos, "%u", udev->minor);
+                       dbg("substitute minor number '%u'", udev->minor);
+                       break;
                        case 'M':
-                               sprintf(pos, "%u", udev->major);
-                               dbg("substitute major number '%u'", udev->major);
+                       sprintf(pos, "%u", udev->major);
+                       dbg("substitute major number '%u'", udev->major);
+                       break;
+               case 'c':
+                       if (strlen(udev->program_result) == 0)
                                break;
-                       case 'c':
-                               if (strlen(udev->program_result) == 0)
-                                       break;
-                               if (num) {
-                                       /* get part of return string */
-                                       strncpy(temp1, udev->program_result, sizeof(temp1));
-                                       pos2 = temp1;
-                                       while (num) {
-                                               num--;
-                                               pos3 = strsep(&pos2, " ");
-                                               if (pos3 == NULL) {
-                                                       dbg("requested part of result string not found");
-                                                       break;
-                                               }
+                       /* get part part of the result string */
+                       i = num; /* num syntax is deprecated and will be removed  */
+                       if (attr != NULL)
+                               i = atoi(attr);
+                       if (i > 0) {
+                               strfieldcpy(temp1, udev->program_result);
+                               pos2 = temp1;
+                               while (i) {
+                                       i--;
+                                       pos3 = strsep(&pos2, " ");
+                                       if (pos3 == NULL) {
+                                               dbg("requested part of result string not found");
+                                               break;
                                        }
-                                       if (pos3) {
-                                               strcat(pos, pos3);
-                                               dbg("substitute part of result string '%s'", pos3);
-                                       }
-                               } else {
-                                       strcat(pos, udev->program_result);
-                                       dbg("substitute result string '%s'", udev->program_result);
                                }
-                               break;
-                       case '%':
-                               strcat(pos, "%");
-                               pos++;
-                               break;
-                       default:
-                               dbg("unknown substitution type '%%%c'", pos[1]);
-                               break;
+                               if (pos3) {
+                                       strnfieldcat(pos, pos3, maxsize);
+                                       dbg("substitute part of result string '%s'", pos3);
+                               }
+                       } else {
+                               strnfieldcat(pos, udev->program_result, maxsize);
+                               dbg("substitute result string '%s'", udev->program_result);
+                       }
+                       break;
+               case 's':
+                       if (attr != NULL) {
+                               tmpattr = find_sysfs_attribute(class_dev, sysfs_device, attr);
+                               if (tmpattr == NULL) {
+                                       dbg("sysfa attribute '%s' not found", attr);
+                                       break;
+                               }
+                               strnfieldcpy(pos, tmpattr->value, maxsize);
+                               dbg("substitute sysfs value '%s'", tmpattr->value);
+                       } else {
+                               dbg("missing attribute");
                        }
-                       strcat(string, temp);
-               } else
                        break;
+               case '%':
+                       strnfieldcat(pos, "%", maxsize);
+                       break;
+               default:
+                       dbg("unknown substitution type '%%%c'", c);
+                       break;
+               }
+               strnfieldcat(pos, tail, maxsize);
        }
 }
 
@@ -403,7 +464,7 @@ static int execute_program(char *path, char *value, int len)
                                strncpy(value, buffer, len);
                                pos = value + strlen(value)-1;
                                if (pos[0] == '\n')
-                               pos[0] = '\0';
+                                       pos[0] = '\0';
                                dbg("result is '%s'", value);
                        }
                }
@@ -422,32 +483,46 @@ static int execute_program(char *path, char *value, int len)
        return retval;
 }
 
-static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct sysfs_pair *pair)
+static struct sysfs_attribute *find_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, char *attr)
 {
        struct sysfs_attribute *tmpattr = NULL;
        char *c;
 
-       if ((pair == NULL) || (pair->file[0] == '\0') || (pair->value == '\0'))
-               return -ENODEV;
-
-       dbg("look for device attribute '%s'", pair->file);
+       dbg("look for device attribute '%s'", attr);
        /* try to find the attribute in the class device directory */
-       tmpattr = sysfs_get_classdev_attr(class_dev, pair->file);
+       tmpattr = sysfs_get_classdev_attr(class_dev, attr);
        if (tmpattr)
-               goto label_found;
+               goto attr_found;
 
        /* look in the class device directory if present */
        if (sysfs_device) {
-               tmpattr = sysfs_get_device_attr(sysfs_device, pair->file);
+               tmpattr = sysfs_get_device_attr(sysfs_device, attr);
                if (tmpattr)
-                       goto label_found;
+                       goto attr_found;
        }
-       return -ENODEV;
 
-label_found:
-       c = tmpattr->value + strlen(tmpattr->value)-1;
-       if (*c == '\n')
-               *c = 0x00;
+       return NULL;
+
+attr_found:
+       c = strchr(tmpattr->value, '\n');
+       if (c != NULL)
+               c[0] = '\0';
+
+       dbg("found attribute '%s'", tmpattr->path);
+       return tmpattr;
+}
+
+static int compare_sysfs_attribute(struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device, struct sysfs_pair *pair)
+{
+       struct sysfs_attribute *tmpattr;
+
+       if ((pair == NULL) || (pair->file[0] == '\0') || (pair->value == '\0'))
+               return -ENODEV;
+
+       tmpattr = find_sysfs_attribute(class_dev, sysfs_device, pair->file);
+       if (tmpattr == NULL)
+               return -ENODEV;
+
        dbg("compare attribute '%s' value '%s' with '%s'",
                  pair->file, tmpattr->value, pair->value);
        if (strcmp_pattern(pair->value, tmpattr->value) != 0)
@@ -550,7 +625,8 @@ static struct sysfs_device *get_sysfs_device(struct sysfs_class_device *class_de
        tspec.tv_nsec = 10000000;  /* sleep 10 millisec */
        loop = 10;
        while (loop--) {
-               nanosleep(&tspec, NULL);
+               if (udev_sleep)
+                       nanosleep(&tspec, NULL);
                if (class_dev_parent)
                        sysfs_device = sysfs_get_classdev_device(class_dev_parent);
                else
@@ -577,7 +653,8 @@ device_found:
                loop = 10;
                tspec.tv_nsec = 10000000;
                while (loop--) {
-                       nanosleep(&tspec, NULL);
+                       if (udev_sleep)
+                               nanosleep(&tspec, NULL);
                        sysfs_get_device_bus(sysfs_device);
                        
                        if (sysfs_device->bus[0] != '\0')
@@ -658,7 +735,8 @@ static int match_rule(struct config_device *dev, struct sysfs_class_device *clas
                /* execute external program */
                if (dev->program[0] != '\0') {
                        dbg("check " FIELD_PROGRAM);
-                       apply_format(udev, dev->program);
+                       apply_format(udev, dev->program, sizeof(dev->program),
+                                    class_dev, sysfs_device);
                        if (execute_program(dev->program, udev->program_result, NAME_SIZE) != 0) {
                                dbg(FIELD_PROGRAM " returned nozero");
                                goto try_parent;
@@ -750,9 +828,11 @@ int namedev_name_device(struct sysfs_class_device *class_dev, struct udevice *ud
 
 found:
        /* substitute placeholder */
-       apply_format(udev, udev->name);
-       apply_format(udev, udev->symlink);
-
+       apply_format(udev, udev->name, sizeof(udev->name),
+                    class_dev, sysfs_device);
+       apply_format(udev, udev->symlink, sizeof(udev->symlink),
+                    class_dev, sysfs_device);
+       udev->partitions = dev->partitions;
 done:
        perm = find_perm(udev->name);
        if (perm) {
@@ -762,8 +842,8 @@ done:
        } else {
                /* no matching perms found :( */
                udev->mode = get_default_mode();
-               strncpy(udev->owner, get_default_owner(), OWNER_SIZE);
-               strncpy(udev->group, get_default_group(), GROUP_SIZE);
+               strfieldcpy(udev->owner, get_default_owner());
+               strfieldcpy(udev->group, get_default_group());
        }
        dbg("name, '%s' is going to have owner='%s', group='%s', mode = %#o",
            udev->name, udev->owner, udev->group, udev->mode);