89 lines
1.8 KiB
C
89 lines
1.8 KiB
C
/*
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* Copyright (c) 2026 Mirocom Laboratories and MSP engineers.
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* All Rights Reserved.
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*/
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#include <stdint.h>
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#include <stddef.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <string.h>
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#include <assert.h>
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#include "mvm/balloon.h"
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int
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balloon_init(struct mvm_balloon *bp, size_t cap)
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{
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if (bp == NULL || cap == 0) {
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errno = EINVAL;
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return -1;
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}
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assert(cap > BALLOON_INIT_SIZE && "cap must be bigger than minimum");
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bp->cap = cap;
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bp->size = BALLOON_INIT_SIZE;
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bp->data = calloc(bp->size, sizeof(char));
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if (bp->data == NULL) {
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errno = ENOMEM;
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return -1;
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}
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return 0;
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}
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int
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balloon_memcpy(struct mvm_balloon *dest, off_t off, void *source, size_t count)
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{
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size_t overflow, newsize;
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size_t delta;
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void *p;
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if (dest == NULL || source == NULL) {
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errno = EINVAL;
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return -1;
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}
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if (count == 0) {
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errno = EINVAL;
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return -1;
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}
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/* Compute how far off this will push us */
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overflow = off + count;
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/* If we are overflowing size and have room to expand, do it */
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if (overflow >= dest->size && dest->size < dest->cap) {
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delta = overflow - dest->size;
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newsize = dest->size + delta;
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/* Attempt to resize the pool */
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if ((p = realloc(dest->data, newsize)) == NULL) {
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errno = ENOMEM;
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return -1;
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}
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dest->size = newsize;
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dest->data = p;
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} else if (overflow >= dest->cap) {
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errno = ENOSPC;
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return -1;
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}
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memcpy((char *)dest->data + off, source, count);
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return 0;
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}
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void
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balloon_free(struct mvm_balloon *bp)
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{
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if (bp == NULL) {
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return;
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}
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if (bp->data != NULL) {
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free(bp->data);
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bp->data = NULL;
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}
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}
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