bak

2026-01-25 19:21:35 +01:00 · 2019-05-05 00:00:00 +00:00
parent 0ef494b681
commit aea97698c3
48 changed files with 840 additions and 798 deletions
--- a/userland/kernel_modules/anonymous_inode.c
+++ b/userland/kernel_modules/anonymous_inode.c
@@ -0,0 +1,45 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#anonymous-inode */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h> /* sleep */
+
+#include <include/anonymous_inode.h>
+
+int main(int argc, char **argv) {
+    char buf[1024];
+    int fd_ioctl, fd_ioctl_anon, ret;
+    size_t i, nreads;
+
+    if (argc < 2) {
+        puts("Usage: ./prog <ioctl-file> [<nreads>]");
+        return EXIT_FAILURE;
+    } else if (argc > 2) {
+        nreads = strtol(argv[2], NULL, 10);
+    } else {
+        nreads = 3;
+    }
+    fd_ioctl = open(argv[1], O_RDONLY);
+    if (fd_ioctl == -1) {
+        perror("open");
+        return EXIT_FAILURE;
+    }
+    ret = ioctl(fd_ioctl, LKMC_ANONYMOUS_INODE_GET_FD, &fd_ioctl_anon);
+    if (ret == -1) {
+        perror("ioctl");
+        return EXIT_FAILURE;
+    }
+    for (i = 0; i < nreads; ++i) {
+        ret = read(fd_ioctl_anon, buf, sizeof(buf));
+        printf("%.*s\n", ret, buf);
+    }
+    close(fd_ioctl_anon);
+    close(fd_ioctl);
+    return EXIT_SUCCESS;
+}
--- a/userland/kernel_modules/ioctl.c
+++ b/userland/kernel_modules/ioctl.c
@@ -0,0 +1,66 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#ioctl */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <include/ioctl.h>
+
+int main(int argc, char **argv) {
+    char *ioctl_path;
+    int fd, request, arg0, arg1, arg_int, ret;
+    lkmc_ioctl_struct arg_struct;
+
+    if (argc < 2) {
+        puts("Usage: ./prog <ioctl-file> <request> [<arg>...]");
+        return EXIT_FAILURE;
+    }
+    ioctl_path = argv[1];
+    request = strtol(argv[2], NULL, 10);
+    if (argc > 3) {
+        arg0 = strtol(argv[3], NULL, 10);
+    }
+    if (argc > 4) {
+        arg1 = strtol(argv[4], NULL, 10);
+    }
+
+    fd = open(ioctl_path, O_RDONLY);
+    if (fd == -1) {
+        perror("open");
+        return EXIT_FAILURE;
+    }
+    switch (request)
+    {
+        case 0:
+            arg_int = arg0;
+            ret = ioctl(fd, LKMC_IOCTL_INC, &arg_int);
+            if (ret != -1) {
+                printf("%d\n", arg_int);
+            }
+            break;
+        case 1:
+            arg_struct.i = arg0;
+            arg_struct.j = arg1;
+            ret = ioctl(fd, LKMC_IOCTL_INC_DEC, &arg_struct);
+            if (ret != -1) {
+                printf("%d %d\n", arg_struct.i, arg_struct.j);
+            }
+            break;
+        default:
+            puts("error: unknown request");
+            return EXIT_FAILURE;
+    }
+    if (ret == -1) {
+        perror("ioctl");
+        printf("errno = %d\n", errno);
+        return EXIT_FAILURE;
+    }
+    close(fd);
+    return EXIT_SUCCESS;
+}
--- a/userland/kernel_modules/netlink.c
+++ b/userland/kernel_modules/netlink.c
@@ -0,0 +1,51 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#netlink-sockets */
+
+#include <linux/netlink.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include <include/netlink.h>
+
+#define MAX_PAYLOAD 1024
+
+/* Some of these structs fields must be zeroed.
+ * We could brute force memset them, but
+ * TODO determine exactly which, and move into main. */
+int sock_fd;
+struct iovec iov;
+struct msghdr msg;
+struct nlmsghdr *nlh;
+struct sockaddr_nl src_addr, dest_addr;
+
+int main(void) {
+    sock_fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_USER);
+    if (sock_fd < 0) {
+        perror("socket");
+        return EXIT_FAILURE;
+    }
+    src_addr.nl_family = AF_NETLINK;
+    src_addr.nl_pid = getpid();
+    bind(sock_fd, (struct sockaddr *)&src_addr, sizeof(src_addr));
+    dest_addr.nl_family = AF_NETLINK;
+    nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(MAX_PAYLOAD));
+    memset(nlh, 0, NLMSG_SPACE(MAX_PAYLOAD));
+    nlh->nlmsg_len = NLMSG_SPACE(MAX_PAYLOAD);
+    nlh->nlmsg_pid = getpid();
+    nlh->nlmsg_flags = 0;
+    strcpy(NLMSG_DATA(nlh), "user request");
+    iov.iov_base = (void *)nlh;
+    iov.iov_len = nlh->nlmsg_len;
+    msg.msg_name = (void *)&dest_addr;
+    msg.msg_namelen = sizeof(dest_addr);
+    msg.msg_iov = &iov;
+    msg.msg_iovlen = 1;
+    fprintf(stderr, "before sendmsg\n");
+    sendmsg(sock_fd, &msg, 0);
+    fprintf(stderr, "after sendmsg\n");
+    recvmsg(sock_fd, &msg, 0);
+    printf("%s\n", (char *)NLMSG_DATA(nlh));
+    close(sock_fd);
+}
--- a/userland/kernel_modules/poll.c
+++ b/userland/kernel_modules/poll.c
@@ -0,0 +1,41 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#poll */
+
+#define _XOPEN_SOURCE 700
+#include <assert.h>
+#include <fcntl.h> /* creat, O_CREAT */
+#include <poll.h> /* poll */
+#include <stdio.h> /* printf, puts, snprintf */
+#include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS */
+#include <unistd.h> /* read */
+
+int main(int argc, char **argv) {
+    char buf[1024];
+    int fd, i, n;
+    short revents;
+    struct pollfd pfd;
+
+    if (argc < 2) {
+        fprintf(stderr, "usage: %s <poll-device>\n", argv[0]);
+        exit(EXIT_FAILURE);
+    }
+    fd = open(argv[1], O_RDONLY | O_NONBLOCK);
+    if (fd == -1) {
+        perror("open");
+        exit(EXIT_FAILURE);
+    }
+    pfd.fd = fd;
+    pfd.events = POLLIN;
+    while (1) {
+        puts("loop");
+        i = poll(&pfd, 1, -1);
+        if (i == -1) {
+            perror("poll");
+            assert(0);
+        }
+        revents = pfd.revents;
+        if (revents & POLLIN) {
+            n = read(pfd.fd, buf, sizeof(buf));
+            printf("POLLIN n=%d buf=%.*s\n", n, n, buf);
+        }
+    }
+}
--- a/userland/kernel_modules/uio_read.c
+++ b/userland/kernel_modules/uio_read.c
@@ -0,0 +1,111 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#uio */
+
+#if 1
+
+/* Adapted from: https://yurovsky.github.io/2014/10/10/linux-uio-gpio-interrupt */
+
+#define _XOPEN_SOURCE 700
+#include <fcntl.h> /* open */
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h> /* write */
+
+#include <assert.h>
+#include <sys/mman.h>
+
+int main(int argc, char **argv) {
+    char *dev = "/dev/uio0";
+    if (argc > 1) {
+        dev = argv[1];
+        exit(EXIT_FAILURE);
+    }
+    int fd = open(dev, O_RDWR);
+    if (fd < 0) {
+        perror("open");
+        exit(EXIT_FAILURE);
+    }
+
+    /* TODO not supported by this kernel module? */
+#if 0
+    int *addr = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (addr == MAP_FAILED) {
+        perror("mmap");
+        assert(0);
+    }
+    *addr = 0x12345678;
+#endif
+
+    while (1) {
+        uint32_t info = 1;
+        size_t nb = write(fd, &info, sizeof(info));
+        if (nb < sizeof(info)) {
+            perror("write");
+            close(fd);
+            exit(EXIT_FAILURE);
+        }
+        nb = read(fd, &info, sizeof(info));
+        if (nb == sizeof(info)) {
+            printf(__FILE__ " read = %u\n", info);
+        }
+    }
+}
+
+#else
+
+/* Ripped from the kernel docs. */
+
+#define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <unistd.h>
+
+int main(void) {
+    int uiofd;
+    int configfd;
+    int err;
+    int i;
+    unsigned icount;
+    unsigned char command_high;
+
+    uiofd = open("/dev/uio0", O_RDONLY);
+    if (uiofd < 0) {
+        perror("uio open:");
+        return errno;
+    }
+    configfd = open("/sys/class/uio/uio0/device/config", O_RDWR);
+    if (configfd < 0) {
+        perror("config open:");
+        return errno;
+    }
+    err = pread(configfd, &command_high, 1, 5);
+    if (err != 1) {
+        perror("command config read:");
+        return errno;
+    }
+    command_high &= ~0x4;
+    for(i = 0;; ++i) {
+        fprintf(stderr, "Interrupts: %d\n", icount);
+        err = pwrite(configfd, &command_high, 1, 5);
+        if (err != 1) {
+            perror("config write:");
+            break;
+        }
+        err = read(uiofd, &icount, 4);
+        if (err != 4) {
+            perror("uio read:");
+            break;
+        }
+
+    }
+    return errno;
+}
+
+#endif