ulist.c File Reference

#include "ulist.h"
#include <linux/err.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "config.h"
#include "io.h"

Include dependency graph for ulist.c:

Go to the source code of this file.

Functions
static bool	ulist_has_item (struct ulist *ul, const char *value)
void	ulist_clear (struct ulist *ul)
int	ulist_load (struct ulist *ul)
int	ulist_save (struct ulist *ul)
int	ulist_add (struct ulist *ul, const char *value, u32 flags, const char *payload)
int	ulist_remove (struct ulist *ul, const char *value)
int	ulist_contains (struct ulist *ul, const char *value)
int	ulist_list (struct ulist *ul, char *buf, size_t buf_size)

Function Documentation

ulist_add()

int ulist_add	(	struct ulist *	ul,
		const char *	value,
		u32	flags,
		const char *	payload
	)

ulist_add - Adds a new item to the ulist.

Parameters

ul	Pointer to the ulist structure.
value	The string value to add.
flags	Flags associated with the item.
payload	Optional payload string (can be NULL).

Returns 0 on success, -EEXIST if the item already exists, or -ENOMEM on memory allocation failure.

Definition at line 208 of file ulist.c.

                                   {
    if (ulist_has_item(ul, value)) {
        return -EEXIST;
    }
 
    struct ulist_item *it = kzalloc(sizeof(*it), GFP_KERNEL);
    if (!it)
        return -ENOMEM;
 
    it->value = kstrdup(value, GFP_KERNEL);
    it->flags = flags;
    it->payload = payload ? kstrdup(payload, GFP_KERNEL) : NULL;
    INIT_LIST_HEAD(&it->list);
 
    spin_lock(&ul->lock);
    list_add_tail(&it->list, &ul->head);
    spin_unlock(&ul->lock);
    return SUCCESS;
}

ulist_clear()

void ulist_clear

(

struct ulist *

ul

)

ulist_clear - Removes and frees all items from a ulist.

Parameters

ul	Pointer to the ulist structure to clear.

Definition at line 39 of file ulist.c.

                                   {
    struct ulist_item *it, *tmp;
    spin_lock(&ul->lock);
    list_for_each_entry_safe(it, tmp, &ul->head, list) {
        list_del(&it->list);
        kfree(it->value);
        kfree(it->payload);
        kfree(it);
    }
    spin_unlock(&ul->lock);
}

ulist_contains()

int ulist_contains	(	struct ulist *	ul,
		const char *	value
	)

ulist_contains - Checks if a value exists in the ulist.

Parameters

ul	Pointer to the ulist structure.
value	The string value to check for.

Returns 1 if the value is found, 0 otherwise.

Definition at line 258 of file ulist.c.

                                                        {
    struct ulist_item *it;
    int found = 0;
 
    spin_lock(&ul->lock);
    list_for_each_entry(it, &ul->head, list) {
        if (!strcmp(it->value, value)) {
            found = 1;
            break;
        }
    }
    spin_unlock(&ul->lock);
    return found;
}

ulist_has_item()

static bool ulist_has_item ( struct ulist *  ul, const char *  value  )

static

ulist_has_item - Checks if a value exists in the ulist.

Parameters

ul	Pointer to the ulist structure to search.
value	The string value to look for in the list. Note: Only the value field is compared; flags and payload are ignored.

Return: true if the value is found in the list, false otherwise.

Definition at line 23 of file ulist.c.

                                                                {
    struct ulist_item *it;
 
    // Check only the value in the list
    // (we don't care about flags or payload)
    list_for_each_entry(it, &ul->head, list) {
        if (strcmp(it->value, value) == 0)
            return true;
    }
    return false;
}

ulist_list()

int ulist_list	(	struct ulist *	ul,
		char *	buf,
		size_t	buf_size
	)

ulist_list - Lists all items in the ulist into a buffer.

Parameters

ul	Pointer to the ulist structure.
buf	Buffer to store the list of items.
buf_size	Size of the buffer.

Returns the number of bytes written to the buffer, or a negative error code on failure. The format is "value|flags|payload\n" for each item.

Definition at line 282 of file ulist.c.

                                                             {
    struct ulist_item *it;
    size_t left = buf_size;
    char *p = buf;
    int n;
 
    if (!ul || !buf || buf_size == 0)
        return -EINVAL;
 
    spin_lock(&ul->lock);
    list_for_each_entry(it, &ul->head, list) {
        n = scnprintf(p, left, "%s|%u|%s\n", it->value, it->flags,
                      it->payload ?: "");
        if (n >= left)
            break;
        p += n;
        left -= n;
    }
    spin_unlock(&ul->lock);
 
    if (left > 0)
        *p = '\0';
    else
        buf[buf_size - 1] = '\0';
 
    return p - buf;
}

ulist_load()

int ulist_load

(

struct ulist *

ul

)

ulist_init - Initializes a ulist structure.

Parameters

ul	Pointer to the ulist structure to initialize.

Initializes the ulist structure, setting up the lock and list head, and storing the filename for later use in loading/saving.

Definition at line 58 of file ulist.c.

                                 {
    char cfgpath[512];
    char *buf = NULL;
    char *p, *newline;
    int ret;
 
    if (!ul || !ul->filename) {
        ERR_MSG("ulist_load: invalid arguments ul=%p filename=%p\n", ul,
                ul ? ul->filename : NULL);
        return -EINVAL;
    }
    build_cfg_path(ul->filename, cfgpath, sizeof(cfgpath));
 
    ret = _read_file(cfgpath, &buf);
    if (ret < 0) {
        if (ret == -ENOENT) {
            DBG_MSG("ulist_load: no config file '%s'\n", cfgpath);
            return 0;
        }
        ERR_MSG("ulist_load: error reading '%s': %d\n", cfgpath, ret);
        return ret;
    }
 
    if (!buf[0]) {
        DBG_MSG("ulist_load: empty config '%s'\n", cfgpath);
        kfree(buf);
        return 0;
    }
 
    p = buf;
    while (*p) {
        char line[ULIST_LINE_MAX];
        size_t len;
        char *fields[3] = { NULL, NULL, NULL };
        char *cursor;
        u32 flags = 0;
        char *payload = NULL;
        int rc;
 
        // Find end of this line
        newline = strpbrk(p, "\r\n");
        len = newline ? (newline - p) : strlen(p);
 
        // Skip empty lines
        if (len == 0) {
            if (!newline)
                break;
            p = newline + 1;
            continue;
        }
 
        // Clamp overly long lines
        if (len >= ULIST_LINE_MAX) {
            ERR_MSG("ulist_load: skipping too-long line\n");
            if (!newline)
                break;
            p = newline + 1;
            continue;
        }
 
        memcpy(line, p, len);
        line[len] = '\0';
 
        // Split into exactly three fields around '|'
        cursor = line;
        fields[0] = strsep(&cursor, "|");
        fields[1] = strsep(&cursor, "|");
        fields[2] = cursor;
 
        // The field[0] must be non-empty eheh
        if (!fields[0] || !*fields[0]) {
            ERR_MSG("ulist_load: missing value, skipping line\n");
            if (!newline)
                break;
            p = newline + 1;
        }
 
        // Parse flags (default to 0 on error)
        if (fields[1] && *fields[1]) {
            int err = kstrtou32(fields[1], 10, &flags);
            if (err) {
                ERR_MSG("ulist_load: bad flags '%s', using 0\n", fields[1]);
                flags = 0;
            }
        }
 
        // Payload may be empty string so treat it as NULL lol
        if (fields[2] && *fields[2])
            payload = fields[2];
 
        // Add to list
        rc = ulist_add(ul, fields[0], flags, payload);
        if (rc < 0)
            ERR_MSG("ulist_load: ulist_add(%s) failed: %d\n", fields[0], rc);
 
        if (!newline)
            break;
        p = newline + 1;
    }
 
    kfree(buf);
    return 0;
}

ulist_remove()

int ulist_remove	(	struct ulist *	ul,
		const char *	value
	)

ulist_remove - Removes an item from the ulist by value.

Parameters

ul	Pointer to the ulist structure.
value	The string value to remove.

Returns 0 on success, or -ENOENT if the item was not found.

Definition at line 236 of file ulist.c.

                                                      {
    struct ulist_item *it, *tmp;
    spin_lock(&ul->lock);
    list_for_each_entry_safe(it, tmp, &ul->head, list) {
        if (!strcmp(it->value, value)) {
            list_del(&it->list);
            kfree(it->value);
            kfree(it->payload);
            kfree(it);
        }
    }
    spin_unlock(&ul->lock);
    return 0;
}

ulist_save()

int ulist_save

(

struct ulist *

ul

)

ulist_init - Initializes a ulist structure.

Parameters

ul	Pointer to the ulist structure to initialize.

Initializes the ulist structure, setting up the lock and list head, and storing the filename for later use in loading/saving.

Definition at line 169 of file ulist.c.

                                 {
    char cfgpath[128];
    char *buf, *q;
    size_t left = STD_BUFFER_SIZE;
    struct ulist_item *it;
    int ret;
 
    buf = kzalloc(STD_BUFFER_SIZE, GFP_KERNEL);
    if (!buf)
        return -ENOMEM;
    q = buf;
 
    spin_lock(&ul->lock);
    list_for_each_entry(it, &ul->head, list) {
        int n = scnprintf(q, left, "%s|%u|%s\n", it->value, it->flags,
                          it->payload ?: "");
        q += n;
        left -= n;
        if (left <= 0)
            break;
    }
    spin_unlock(&ul->lock);
 
    build_cfg_path(ul->filename, cfgpath, sizeof(cfgpath));
    ret = _write_file(cfgpath, buf, q - buf);
    kfree(buf);
    return ret > 0 ? 1 : ret;
}