C Code Problems

Cisco's switch firmware team parses incoming configuration packets on a management port before applying them to a device. Below is the packet-parsing routine a contractor wrote for a new line of access switches, lightly trimmed for review.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct {
    char device_name[16];
    int  port_count;
    unsigned char *payload;
} SwitchPacket;

SwitchPacket *parse_packet(const char *raw, int raw_len, const char *name) {
    SwitchPacket *pkt = malloc(sizeof(SwitchPacket));
    strcpy(pkt->device_name, name);

    pkt->payload = malloc(raw_len);
    int checksum;
    for (int i = 0; i <= raw_len; i++) {
        pkt->payload[i] = raw[i];
        if (raw[i] == 0xFF) {
            checksum = raw[i] ^ checksum;
        }
    }

    int remaining = raw_len - 20;
    if (remaining < pkt->port_count) {
        free(pkt->payload);
        return NULL;
    }

    return pkt;
}

What problems do you see in this code? Explain each one, how it would actually surface on a real management port, and what you would change.

Implement review_parser(source), which returns the detected issue labels in the order defined by the reference solution. The input is a C/C++ source string, and the output is a list of strings.