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authorLoïc Collignon <loic.collignon@iot.bzh>2017-07-11 06:36:33 +0200
committerLoïc Collignon <loic.collignon@iot.bzh>2017-07-11 06:36:33 +0200
commit0455a7401f9f0f9bfad82c5ddf04f7dd70b0b852 (patch)
tree819bc150cb62c8eb344656086bbb52892f5288b8 /idkey
parent66b90d26cfd555b2aa5fef67d31e539a70256719 (diff)
first somewhat working version.
Change-Id: I3101dc6b8add87eccac3bbf177b1320137f72463 Signed-off-by: Loïc Collignon <loic.collignon@iot.bzh>
Diffstat (limited to 'idkey')
-rw-r--r--idkey/CMakeLists.txt6
-rw-r--r--idkey/main.c127
2 files changed, 133 insertions, 0 deletions
diff --git a/idkey/CMakeLists.txt b/idkey/CMakeLists.txt
new file mode 100644
index 0000000..dc1f8cb
--- /dev/null
+++ b/idkey/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.3)
+project(idkey)
+add_executable(idkey main.c)
+install(TARGETS idkey
+ RUNTIME DESTINATION bin
+ LIBRARY DESTINATION lib)
diff --git a/idkey/main.c b/idkey/main.c
new file mode 100644
index 0000000..16b2232
--- /dev/null
+++ b/idkey/main.c
@@ -0,0 +1,127 @@
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define EXIT_SUCCESS 0
+#define EXIT_CMDLINE 1
+#define EXIT_FILEOPEN 2
+#define EXIT_FILEREAD 3
+#define EXIT_FILEWRITE 4
+#define EXIT_INVALID 5
+#define EXIT_ALLOC 6
+
+#define BLOCK_SIZE 4096
+
+/// @brief Header of the datas.
+typedef struct header_
+{
+ char mn[4];
+ size_t size;
+} header;
+
+/// @brief Check if the @c v is a valid magick number.
+/// @param[in] v magick number.
+/// @return 1 if valid, zero otherwise.
+int is_valid_nm(const char* v)
+{
+ return v && v[0] == 'I' && v[1] == 'D' && v[2] == 'K' && v[3] == 'Y';
+}
+
+/// @brief Close the file descriptor if valid then print a formatted error message then return the specified code.
+/// @param[in] fd File descriptor to close.
+/// @param[in] code The exit code to return.
+/// @param[in] format The message to print.
+/// @param[in] ... Values for formatting.
+/// @return The exit code provided by @c code.
+int close_and_fail(int fd, int code, const char* format, ...)
+{
+ va_list arglist;
+ fprintf(stderr, "Error: ");
+ va_start(arglist, format);
+ vfprintf(stderr, format, arglist);
+ va_end(arglist);
+ fprintf(stderr, "\n");
+ return code;
+}
+
+/// @brief Read the device @c devname and print it's data to stdout.
+/// @param[in] devname Device's name.
+/// @return Exit code, zero if success.
+int read_device(const char* devname)
+{
+ int fd = open(devname, O_RDONLY);
+ if (fd == -1) return close_and_fail(fd, EXIT_FILEOPEN, "Failed to open '%s'!", devname);
+
+ header h;
+ ssize_t sz = read(fd, &h, sizeof(header));
+ if (sz != sizeof(header)) return close_and_fail(fd, EXIT_FILEREAD, "Failed to read the header!");
+ if (!is_valid_nm(h.mn)) return close_and_fail(fd, EXIT_INVALID, "Not a valid identity key!");
+
+ while(h.size)
+ {
+ char datas[BLOCK_SIZE + 1];
+ memset(datas, BLOCK_SIZE +1, 0);
+ size_t count = BLOCK_SIZE > h.size ? h.size : BLOCK_SIZE;
+
+ sz = read(fd, datas, count);
+
+ if (sz != count) close_and_fail(fd, EXIT_FILEREAD, "Failed to read a data block!");
+ h.size = (h.size - count);
+
+ printf(datas);
+ }
+ printf("\n");
+ close(fd);
+ return EXIT_SUCCESS;
+}
+
+/// @brief Write the specified data to the specified device.
+/// @param[in] devname Name of the device.
+/// @param[in] datas Datas to write.
+/// @return Exit code, zero if success, non-zero otherwise.
+int write_device(const char* devname, const char* datas)
+{
+ header h = {
+ .mn = {'I', 'D', 'K', 'Y'},
+ .size = strlen(datas)
+ };
+ if (h.size < 1) return close_and_fail(-1, EXIT_CMDLINE, "No data to write!");
+
+ int fd = open(devname, O_WRONLY);
+ if (fd == -1) return close_and_fail(fd, EXIT_FILEOPEN, "Failed to open device '%s'!", devname);
+ if (write(fd, &h, sizeof(header)) != sizeof(header)) return close_and_fail(fd, EXIT_FILEWRITE, "Failed to write the header!");
+ if (write(fd, datas, h.size) != h.size) return close_and_fail(fd, EXIT_FILEWRITE, "Failed to write datas!");
+
+ close(fd);
+ return EXIT_SUCCESS;
+}
+
+/// @brief Entry point.
+/// @param[in] argc Number of arguments in @c argv.
+/// @param[in] argv Arguments array.
+/// @return Exit code, zero if success, non-zero otherwise.
+int main(int argc, char** argv)
+{
+ switch(argc)
+ {
+ case 0:
+ case 1:
+ fprintf(stderr, "ERROR: too few arguments!\n");
+ return EXIT_CMDLINE;
+
+ case 2: // Read the device
+ return read_device(argv[1]);
+
+ case 3: // Write the device
+ return write_device(argv[1], argv[2]);
+
+ default:
+ fprintf(stderr, "ERROR: too many arguments!\n");
+ return EXIT_CMDLINE;
+ }
+}
+