os_mbuf_copydata

int os_mbuf_copydata(const struct os_mbuf *m, int off, int len, void *dst)

Copy data from an mbuf chain starting off bytes from the beginning, continuing for len bytes, into the indicated buffer.

Arguments

Arguments	Description
m	Pointer to mbuf chain
off	Start copy offset, in bytes, from beginning of mbuf chain
len	Number of bytes to copy
dst	Data buffer to copy into

Returned values

0: success.
-1: The mbuf does not contain enough data

Example

    int rc;
	struct os_mbuf *om;
    struct my_hdr_1 my_hdr1;	
    struct my_hdr_2 my_hdr2;	
	
    /* Header 1 and Header 2 are contiguous in packet at start. Retrieve them from the mbuf chain */	
    rc = os_mbuf_copydata(om, 0, sizeof(struct my_hdr_1), &my_hdr1);
    if (rc) {
        /* error! */
        return -1;
    }

    rc = os_mbuf_copydata(om, sizeof(struct my_hdr_1), sizeof(struct my_hdr_2), &my_hdr2);
    if (rc) {
        /* error! */
        return -1;
    }