commit 8a702660477388d46a2a03ca7d185c5571f8c54d
parent dc42e7fe26be17c2514eb2ecb6eefe9705d0711b
Author: Friedel Schoen <[email protected]>
Date: Thu, 29 Dec 2022 01:55:23 +0100
documenting code
Diffstat:
9 files changed, 112 insertions(+), 52 deletions(-)
diff --git a/incl/common.h b/incl/common.h
@@ -1,8 +1,17 @@
#pragma once
+/**
+ * program dies, if pid == 1 the program hangs in a while(1)-loop otherwise exit(1)
+ */
void die() __attribute__((noreturn));
+/**
+ * strdup but it returns NULL if `str` is empty
+ */
char* strdupn(const char* str);
+/**
+ * just comparing strings
+ */
#define streq(a, b) \
(strcmp((a), (b)) == 0)
diff --git a/incl/config.h b/incl/config.h
@@ -35,13 +35,40 @@ typedef enum parse_error {
} parse_error_t;
+/**
+ * defined sections
+ */
extern section_t sections[];
-extern int section_size;
-extern bool color;
-extern bool verbose;
-extern mount_t mounts[];
-extern int mount_size;
-extern int timeout;
+
+/**
+ * size of defined sections
+ */
+extern int section_size;
+
+/**
+ * if colored output is wished
+ */
+extern bool color;
+
+/**
+ * if debug messages should be printed
+ */
+extern bool verbose;
+
+/**
+ * defined global mounts
+ */
+extern mount_t mounts[];
+
+/**
+ * size of defined global mounts
+ */
+extern int mount_size;
+
+/**
+ * menu timeout (TODO)
+ */
+extern int timeout;
parse_error_t config_parsef(FILE* file, const char* filename);
parse_error_t config_parse(int fd, const char* filename);
diff --git a/incl/console.h b/incl/console.h
@@ -2,6 +2,9 @@
#include "common.h"
+/**
+ * prints debug info
+ */
#define VERBOSE(format...) \
{ \
if (color) { \
@@ -10,6 +13,9 @@
printf("debug: " format); \
}
+/**
+ * prints regular info
+ */
#define INFO(format...) \
{ \
if (color) { \
@@ -18,6 +24,9 @@
printf(":: " format); \
}
+/**
+ * prints a warning
+ */
#define WARN(format...) \
{ \
if (color) \
@@ -26,6 +35,9 @@
printf("warn: " format); \
}
+/**
+ * prints an error and dies
+ */
#define PANIC(format...) \
{ \
if (color) \
@@ -35,5 +47,7 @@
die(); \
}
-
+/**
+ * initiate the console (for pid == 1)
+ */
void init_console();
\ No newline at end of file
diff --git a/incl/default.h b/incl/default.h
@@ -2,14 +2,16 @@
#include "config.h"
+/**
+ * where the config lives
+ */
#ifndef DEFAULT_CONFIG
# define DEFAULT_CONFIG "/etc/dualinit.conf"
#endif
+/**
+ * default init-path if nothing is defined
+ */
#ifndef DEFAULT_INIT
# define DEFAULT_INIT "/sbin/init"
-#endif
-
-#ifndef DEFAULT_EXEC_PATH
-# define DEFAULT_EXEC_PATH "/usr/share/dualinit/bin/init"
#endif
\ No newline at end of file
diff --git a/incl/mount.h b/incl/mount.h
@@ -2,13 +2,18 @@
#include <stdbool.h>
-
typedef struct mount_option {
const char* name;
int flags;
bool invert;
} mount_option_t;
-extern const struct mount_option mount_options[];
+/**
+ * mount options (taken from util-linux)
+ */
+extern const mount_option_t mount_options[];
+/**
+ * parse mount flags to C-flags and remaining options
+ */
int mount_flags(const char* options, const char** dest);
\ No newline at end of file
diff --git a/src/config.c b/src/config.c
@@ -79,8 +79,10 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
char* line = NULL;
char columns[10][100];
+ // `getline` fetches one line from `file`
while ((len = getline(&line_origin, &alloc, file)) > 0) {
linenr++;
+ // as `getline` doesn't add a terminating `\0`, concatinate it
if (len + 1 > (ssize_t) alloc) {
line = realloc(line_origin, alloc = len + 1);
if (line == NULL) {
@@ -96,6 +98,7 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
last_blank = -1;
+ // some truncating
while (isblank(line[0]))
line++, len--;
@@ -111,9 +114,11 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
}
}
+ // if it's an empty string, skip it
if (len == 0)
continue;
+ // parse colums (aka. split by string)
columns_size = 0;
int column_index = 0;
bool string = false;
@@ -135,6 +140,7 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
}
}
+ // end
if (streq(columns[0], "end")) {
CHECK_PARAMS_EQUALS(1);
@@ -146,6 +152,7 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
result = P_SCOPE;
goto error;
}
+ // <fstype> <source> <target> [options]
} else if (in_mount) {
CHECK_PARAMS_BETWEEN(3, 4);
@@ -163,10 +170,12 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
mnt->flags = 0;
mnt->options = NULL;
}
+ // mount
} else if (streq(columns[0], "mount")) {
CHECK_PARAMS_EQUALS(1);
in_mount = true;
+ // section
} else if (streq(columns[0], "section")) {
CHECK_ROOT;
CHECK_PARAMS_EQUALS(3);
@@ -181,6 +190,7 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
current_section->mount_size = 0;
current_section->name = strdupn(columns[1]);
current_section->root = strdupn(columns[2]);
+ // rshare/share <dirs...>
} else if (streq(columns[0], "rshare") || streq(columns[0], "share")) {
CHECK_PARAMS_MORE(2);
@@ -202,16 +212,19 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
if (columns[0][0] == 'r') // aka. equals rshare
mnt->flags |= MS_REC;
}
+ // color <enable>
} else if (streq(columns[0], "color")) {
CHECK_ROOT;
CHECK_PARAMS_EQUALS(2);
PARSE_BOOL(color);
+ // verbose <enable>
} else if (streq(columns[0], "verbose")) {
CHECK_ROOT;
CHECK_PARAMS_EQUALS(2);
PARSE_BOOL(verbose);
+ // timeout <seconds>
} else if (streq(columns[0], "timeout")) {
CHECK_ROOT;
CHECK_PARAMS_EQUALS(2);
@@ -222,6 +235,7 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
result = P_DATA;
goto error;
}
+ // init <path>
} else if (streq(columns[0], "init")) {
CHECK_SECTION;
CHECK_PARAMS_MORE(2);
@@ -232,6 +246,7 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
}
current_section->init = strdupn(columns[1]);
+ // include <file>
} else if (streq(columns[0], "include")) {
CHECK_ROOT;
CHECK_PARAMS_EQUALS(2);
@@ -241,12 +256,14 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
close(fd);
if (result != 0)
goto cleanup;
+ // mmpf, unknown command
} else {
result = P_IDENTIFIER;
goto error;
}
}
+ // if there were no sections, raise an error as that not the intension
if (section_size == 0) {
result = P_SECTION;
goto error;
@@ -257,6 +274,7 @@ parse_error_t config_parsef(FILE* file, const char* filename) {
goto cleanup;
error:
+ // pretty-print error
printf("error in %s:%d: ", filename, linenr);
switch (result) {
case P_ALLOC:
@@ -327,33 +345,4 @@ void config_reset() {
color = false;
verbose = true;
timeout = 10;
-}
-
-
-#if 0
-int main() {
- int fd = open("chinit.conf", O_RDONLY | O_NONBLOCK);
-
- parse_code_t code = parse_config(fd, "chinit.conf");
-
- close(fd);
-
- if (code != P_SUCCESS)
- return 1;
-
-
- for (int j = 0; j < mount_size; j++) {
- printf("- %s%s -> %s [%s] (%s)\n", mounts[j].try ? "try " : "", mounts[j].source, mounts[j].target, mounts[j].type, mounts[j].options);
- }
- for (int i = 0; i < section_size; i++) {
- if (sections[i].name[0] != '\0') {
- printf("%s at %s (%s)\n", sections[i].name, sections[i].root, sections[i].init);
- if (§ions[i] == master)
- printf(" *");
- }
- for (int j = 0; j < sections[i].mount_size; j++) {
- printf("- %s%s -> %s [%s] (%s)\n", sections[i].mounts[j].try ? "try " : "", sections[i].mounts[j].source, sections[i].mounts[j].target, sections[i].mounts[j].type, sections[i].mounts[j].options);
- }
- }
-}
-#endif
-\ No newline at end of file
+}
+\ No newline at end of file
diff --git a/src/console.c b/src/console.c
@@ -3,6 +3,7 @@
#include <fcntl.h>
#include <unistd.h>
+// open /dev/console and pipe it stdout/stdin/stderr
void init_console() {
int in = open("/dev/console", O_RDONLY, 0);
int out = open("/dev/console", O_RDWR, 0);
diff --git a/src/exec/dualinit.c b/src/exec/dualinit.c
@@ -12,7 +12,7 @@
#include <sys/mount.h>
#include <unistd.h>
-
+// mounts `mnt` relative to `root`
static void mount_chroot(const char* root, const mount_t* mnt) {
static char dest[100];
strcpy(dest, root);
@@ -36,26 +36,34 @@ static void mount_chroot(const char* root, const mount_t* mnt) {
}
int main() {
- init_console();
-
if (getpid() != 1) {
PANIC("must run as PID 1\n");
}
- int choice_file = open(DEFAULT_CONFIG, O_RDONLY | O_NONBLOCK);
- if (choice_file == -1) {
+ // initiates the console as it's not initiated if init-system
+ init_console();
+
+ // opens the config file (`fopen` is not working yet)
+ int config_file = open(DEFAULT_CONFIG, O_RDONLY | O_NONBLOCK);
+ if (config_file == -1) {
+ // if it can't be opened, die!
PANIC("cannot open %s: %s\n", DEFAULT_CONFIG, strerror(errno));
}
- parse_error_t parse_code = config_parse(choice_file, DEFAULT_CONFIG);
+ // parse the config
+ parse_error_t parse_code = config_parse(config_file, DEFAULT_CONFIG);
if (parse_code != 0) {
+ // if config can't be parse, die! (again lol)
PANIC("invalid config");
}
- close(choice_file);
+ // and close the file as it's not needed anymore
+ close(config_file);
int section_index;
while (1) {
+ // politely asking for which init you want to load
printf("which init do you want to start?\n");
+ // listing the sections
for (int i = 0; i < section_size; i++) {
printf("[%d] %s at %s\n", i, sections[i].name, sections[i].root);
}
@@ -67,12 +75,14 @@ int main() {
if (section_index >= 0 && section_index < section_size)
break;
+ // mmph, you didn't enter a valid number
WARN("your choice %d must be lower than %d\n\n", section_index, section_size);
}
section_t* section = §ions[section_index];
bool is_root = strcmp(section->root, "/") == 0;
+ // if the section is not `/` (as it should be), mount everything
if (!is_root) {
mount_t self_mount = {
.type = NULL,
@@ -95,6 +105,7 @@ int main() {
}
if (!is_root) {
+ // if it's not '/', chroot into it
INFO("chrooting into %s\n", section->root);
if (chroot(section->root) == -1) {
@@ -102,10 +113,12 @@ int main() {
}
}
+ // chdir '/', otherwise the init-system will have funny errors
if (chdir("/") == -1) {
PANIC("error: cannot chdir into '/': %s\n", strerror(errno));
}
+ // aaand finally entering `init`
char init[PATH_MAX] = DEFAULT_INIT;
if (section->init != NULL)
strcpy(init, section->init);
diff --git a/src/mount.c b/src/mount.c
@@ -5,7 +5,7 @@
#include <sys/mount.h>
-const struct mount_option mount_options[] = {
+const mount_option_t mount_options[] = {
{ "ro", MS_RDONLY, false }, /* read-only */
{ "rw", MS_RDONLY, true }, /* read-write */
{ "exec", MS_NOEXEC, true }, /* permit execution of binaries */
