From 642b5fb0007b64c77d186fcb018d571152ee1d47 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Mon, 14 Aug 2023 18:51:07 +0200
Subject: reorganization: first steps
---
src/cmd/shell/builtins.c | 254 +++++++++++++++++++++++++++++++++++++++++++++++
src/cmd/shell/builtins.h | 10 ++
src/cmd/shell/parser.c | 76 ++++++++++++++
src/cmd/shell/shell.c | 178 +++++++++++++++++++++++++++++++++
src/cmd/shell/shell.h | 11 ++
5 files changed, 529 insertions(+)
create mode 100644 src/cmd/shell/builtins.c
create mode 100644 src/cmd/shell/builtins.h
create mode 100644 src/cmd/shell/parser.c
create mode 100644 src/cmd/shell/shell.c
create mode 100644 src/cmd/shell/shell.h
(limited to 'src/cmd/shell')
diff --git a/src/cmd/shell/builtins.c b/src/cmd/shell/builtins.c
new file mode 100644
index 0000000..9c294b2
--- /dev/null
+++ b/src/cmd/shell/builtins.c
@@ -0,0 +1,254 @@
+#include "builtins.h"
+#include "shell.h"
+#include <camellia.h>
+#include <camellia/fs/misc.h>
+#include <camellia/path.h>
+#include <err.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define DEFAULT_ARGV(...) \
+ char *_argv_default[] = {argv[0], __VA_ARGS__}; \
+ if (argc <= 1) { \
+ argc = sizeof(_argv_default) / sizeof(*_argv_default); \
+ argv = _argv_default; \
+ }
+
+static void cmd_cat(int argc, char **argv) {
+ const size_t buflen = 4096;
+ char *buf = malloc(buflen);
+
+ DEFAULT_ARGV("!stdin");
+ for (int i = 1; i < argc; i++) {
+ FILE *file = fopen(argv[i], "r");
+ if (!file) {
+ perror(argv[i]);
+ return;
+ }
+ if (!strcmp(argv[i], "!stdin")) fextflags(file, FEXT_NOFILL);
+ for (;;) {
+ int len = fread(buf, 1, buflen, file);
+ if (len <= 0) break;
+ fwrite(buf, 1, len, stdout);
+ }
+ if (ferror(file)) {
+ perror(argv[i]);
+ return;
+ }
+ fclose(file);
+ }
+}
+
+static void cmd_echo(int argc, char **argv) {
+ bool newline = true;
+ int i = 1;
+
+ if (!strcmp("-n", argv[i])) {
+ i++;
+ newline = false;
+ }
+
+ printf("%s", argv[i++]);
+ for (; i < argc; i++)
+ printf(" %s", argv[i]);
+ if (newline)
+ printf("\n");
+}
+
+void cmd_getsize(int argc, char **argv) {
+ if (argc < 2) errx(1, "no arguments");
+ for (int i = 1; i < argc; i++) {
+ hid_t h = camellia_open(argv[i], OPEN_READ);
+ if (h < 0) {
+ warn("error opening %s", argv[i]);
+ continue;
+ }
+ printf("%s: %d\n", argv[i], (int)_sys_getsize(h));
+ _sys_close(h);
+ }
+}
+
+void cmd_hexdump(int argc, char **argv) {
+ DEFAULT_ARGV("!stdin");
+ const size_t buflen = 4096;
+ uint8_t *buf = malloc(buflen);
+ FILE *file;
+ bool canonical = strcmp(argv[0], "hd") == 0;
+ size_t readlen = ~0;
+ size_t pos = 0;
+ bool raw = false;
+
+ int c;
+ optind = 0;
+ while ((c = getopt(argc, argv, "Cn:s:r")) != -1) {
+ switch (c) {
+ case 'C':
+ canonical = true;
+ break;
+ case 'n':
+ readlen = strtol(optarg, NULL, 0);
+ break;
+ case 's':
+ pos = strtol(optarg, NULL, 0);
+ break;
+ case 'r': /* "raw" mode, print data as soon as it's read without buffering */
+ raw = true;
+ break;
+ default:
+ return;
+ }
+ }
+ if (readlen != (size_t)~0)
+ readlen += pos;
+
+ for (; optind < argc; optind++) {
+ file = fopen(argv[optind], "r");
+ if (!file) {
+ warn("couldn't open %s", argv[optind]);
+ continue;
+ }
+ if (raw) fextflags(file, FEXT_NOFILL);
+ fseek(file, pos, SEEK_SET);
+ bool skipped = false;
+ while (pos < readlen) {
+ size_t len = buflen;
+ if (len > readlen - pos)
+ len = readlen - pos;
+ len = fread(buf, 1, len, file);
+ if (len == 0) break;
+
+ for (size_t i = 0; i < len; i += 16) {
+ if (i >= 16 && !memcmp(buf + i, buf + i - 16, 16)) {
+ if (!skipped) {
+ printf("*\n");
+ skipped = true;
+ }
+ continue;
+ } else skipped = false;
+ printf("%08zx ", pos + i);
+
+ for (size_t j = i; j < i + 8 && j < len; j++)
+ printf("%02x ", buf[j]);
+ printf(" ");
+ for (size_t j = i + 8; j < i + 16 && j < len; j++)
+ printf("%02x ", buf[j]);
+
+ if (canonical) {
+ printf(" |");
+
+ for (size_t j = i; j < i + 16 && j < len; j++) {
+ char c = '.';
+ if (0x20 <= buf[j] && buf[j] < 0x7f) c = buf[j];
+ printf("%c", c);
+ }
+ printf("|\n");
+ } else {
+ printf("\n");
+ }
+ }
+ pos += len;
+ }
+ printf("%08zx\n", pos);
+ fclose(file);
+ }
+}
+
+static void cmd_ls(int argc, char **argv) {
+ FILE *file;
+ const size_t buflen = 4096;
+ char *buf = malloc(buflen);
+
+ DEFAULT_ARGV(".");
+ for (int i = 1; i < argc; i++) {
+ char *path = (void*)argv[i];
+ int pathlen = strlen(path);
+
+ if (!pathlen || path[pathlen - 1] != '/') {
+ memcpy(buf, path, pathlen);
+ buf[pathlen] = '/';
+ buf[pathlen+1] = '\0';
+ path = buf;
+ }
+
+ file = fopen(path, "r");
+ if (!file) {
+ warn("couldn't open %s", argv[i]);
+ continue;
+ }
+ for (;;) {
+ int len = fread(buf, 1, buflen, file);
+ if (len <= 0) break;
+ for (int i = 0; i < len; i++)
+ if (buf[i] == '\0') buf[i] = '\n';
+ fwrite(buf, 1, len, stdout);
+ }
+ fclose(file);
+ }
+}
+
+static void cmd_mkdir(int argc, char **argv) {
+ // TODO mkdir -p
+ if (argc < 2) errx(1, "no arguments");
+ for (int i = 1; i < argc; i++) {
+ if (mkdir(argv[i], 0777) < 0)
+ perror(argv[i]);
+ }
+}
+
+static void cmd_rm(int argc, char **argv) {
+ if (argc < 2) errx(1, "no arguments");
+ for (int i = 1; i < argc; i++) {
+ if (unlink(argv[i]) < 0)
+ perror(argv[i]);
+ }
+}
+
+static void cmd_sleep(int argc, char **argv) {
+ if (argc < 2) errx(1, "no arguments");
+ _sys_sleep(strtol(argv[1], NULL, 0) * 1000);
+}
+
+static void cmd_touch(int argc, char **argv) {
+ if (argc < 2) errx(1, "no arguments");
+ for (int i = 1; i < argc; i++) {
+ FILE *f = fopen(argv[i], "a");
+ if (!f) perror(argv[i]);
+ fclose(f);
+ }
+}
+
+static void cmd_whitelist(int argc, char **argv) {
+ int split = 1;
+ for (; split < argc;) {
+ if (!strcmp("--", argv[split])) break;
+ split++;
+ }
+ argv[split] = NULL;
+ MOUNT_AT("/") { fs_whitelist((void*)&argv[1]); }
+
+ if (split < argc) {
+ run_args(argc - split - 1, &argv[split + 1], NULL);
+ } else {
+ const char **argv = (const char*[]){"shell", NULL};
+ run_args(1, (void*)argv, NULL);
+ }
+}
+
+struct builtin builtins[] = {
+ {"cat", cmd_cat},
+ {"echo", cmd_echo},
+ {"getsize", cmd_getsize},
+ {"hd", cmd_hexdump},
+ {"hexdump", cmd_hexdump},
+ {"ls", cmd_ls},
+ {"mkdir", cmd_mkdir},
+ {"rm", cmd_rm},
+ {"sleep", cmd_sleep},
+ {"touch", cmd_touch},
+ {"whitelist", cmd_whitelist},
+ {NULL, NULL},
+};
diff --git a/src/cmd/shell/builtins.h b/src/cmd/shell/builtins.h
new file mode 100644
index 0000000..1e422bb
--- /dev/null
+++ b/src/cmd/shell/builtins.h
@@ -0,0 +1,10 @@
+#pragma once
+#include <camellia/syscalls.h>
+#include <stdbool.h>
+
+struct builtin {
+ const char *name;
+ void (*fn)(int argc, char **argv);
+};
+
+extern struct builtin builtins[];
diff --git a/src/cmd/shell/parser.c b/src/cmd/shell/parser.c
new file mode 100644
index 0000000..ad09348
--- /dev/null
+++ b/src/cmd/shell/parser.c
@@ -0,0 +1,76 @@
+#include "shell.h"
+#include <ctype.h>
+#include <stdbool.h>
+#include <string.h>
+
+static char skipspace(char **sp) {
+ char *s = *sp;
+ while (*s && isspace(*s)) s++;
+ *sp = s;
+ return *s;
+}
+
+static bool isspecial(char c) {
+ return c == '>' || c == '#';
+}
+
+static char *parg(char **sp) {
+ char *s = *sp;
+ char *res = NULL;
+
+ if (skipspace(&s)) {
+ // TODO incorrectly handles strings like a"b"
+ switch (*s) {
+ case '"':
+ s++;
+ res = s;
+ while (*s && *s != '"')
+ s++;
+ break;
+ default:
+ res = s;
+ while (*s && !isspace(*s) && !isspecial(*s))
+ s++;
+ if (*s == '#') {
+ *s = '\0'; /* end parsing early */
+ if (res == s) /* don't output an empty arg */
+ res = NULL;
+ }
+ break;
+ }
+ if (*s) *s++ = '\0';
+ }
+
+ *sp = s;
+ return res;
+}
+
+int parse(char *s, char **argv, size_t argvlen, struct redir *redir) {
+ if (argvlen == 0) return -1;
+ size_t argc = 0;
+ char *arg;
+
+ *argv = NULL;
+ redir->stdout = NULL;
+ redir->append = false;
+
+ while (skipspace(&s)) {
+ switch (*s) {
+ case '>':
+ s++;
+ if (*s == '>') {
+ s++;
+ redir->append = true;
+ }
+ redir->stdout = parg(&s);
+ break;
+ default:
+ arg = parg(&s);
+ argv[argc++] = arg;
+ if (argc >= argvlen)
+ return -1;
+ }
+ }
+ argv[argc] = NULL;
+ return argc;
+}
diff --git a/src/cmd/shell/shell.c b/src/cmd/shell/shell.c
new file mode 100644
index 0000000..185aa7e
--- /dev/null
+++ b/src/cmd/shell/shell.c
@@ -0,0 +1,178 @@
+#include "builtins.h"
+#include "shell.h"
+#include <camellia/flags.h>
+#include <camellia/syscalls.h>
+#include <err.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <camellia/fs/misc.h>
+#include <x86intrin.h>
+
+int main();
+
+static void execp(char **argv) {
+ if (!argv || !*argv) return;
+ if (strncmp(argv[0], "/", 1) == 0 ||
+ strncmp(argv[0], "./", 2) == 0 ||
+ strncmp(argv[0], "../", 3) == 0)
+ {
+ execv(argv[0], argv);
+ } else {
+ size_t cmdlen = strlen(argv[0]);
+ char *s = malloc(cmdlen + 6);
+ if (!s) err(1, "malloc");
+ memcpy(s, "/bin/", 5);
+ memcpy(s + 5, argv[0], cmdlen + 1);
+ execv(s, argv);
+ free(s);
+ }
+}
+
+void run_args(int argc, char **argv, struct redir *redir) {
+ if (!*argv) return;
+
+ /* "special" commands that can't be handled in a subprocess */
+ if (!strcmp(argv[0], "mount")) {
+ if (argc < 3) {
+ fprintf(stderr, "mount: not enough arguments\n");
+ return;
+ }
+ MOUNT_AT("/") {
+ fs_dirinject(argv[1]);
+ }
+ MOUNT_AT(argv[1]) {
+ run_args(argc - 2, argv + 2, redir);
+ exit(1);
+ }
+ return;
+ } else if (!strcmp(argv[0], "shadow")) {
+ if (argc < 2) {
+ fprintf(stderr, "shadow: missing path\n");
+ } else {
+ _sys_mount(HANDLE_NULLFS, argv[1], strlen(argv[1]));
+ }
+ } else if (!strcmp(argv[0], "procmnt")) {
+ if (argc < 2) {
+ fprintf(stderr, "procmnt: missing mountpoint\n");
+ return;
+ }
+ _sys_mount(HANDLE_PROCFS, argv[1], strlen(argv[1]));
+ /*
+ if (!(3 <= argc && !strcmp(argv[2], "raw"))) {
+ if (!mount_at("/")) {
+ fs_dirinject(argv[1]);
+ exit(1);
+ }
+ }
+ */
+ return;
+ } else if (!strcmp(argv[0], "cd")) {
+ if (chdir(argc > 1 ? argv[1] : "/") < 0)
+ perror("cd");
+ return;
+ } else if (!strcmp(argv[0], "time")) {
+ uint64_t time = __rdtsc();
+ uint64_t div = 3000;
+ run_args(argc - 1, argv + 1, redir);
+ time = __rdtsc() - time;
+ printf("%lu ns (assuming 3GHz)\n", time / div);
+ return;
+ } else if (!strcmp(argv[0], "exit")) {
+ exit(0);
+ } else if (!strcmp(argv[0], "getpid")) {
+ printf("my\t%d\nparent\t%d\n", getpid(), getppid());
+ return;
+ }
+
+ if (fork()) {
+ _sys_await();
+ return;
+ }
+
+ if (redir && redir->stdout) {
+ FILE *f = fopen(redir->stdout, redir->append ? "a" : "w");
+ if (!f) {
+ err(1, "couldn't open %s for redirection", redir->stdout);
+ }
+
+ /* a workaround for file offsets not being preserved across exec()s.
+ * TODO document that weird behaviour of exec() */
+ hid_t p[2];
+ if (_sys_pipe(p, 0) < 0) {
+ errx(1, "couldn't create redirection pipe");
+ }
+ if (!_sys_fork(FORK_NOREAP, NULL)) {
+ /* the child forwards data from the pipe to the file */
+ const size_t buflen = 512;
+ char *buf = malloc(buflen);
+ if (!buf) err(1, "when redirecting");
+ close(p[1]);
+ for (;;) {
+ long len = _sys_read(p[0], buf, buflen, 0);
+ if (len < 0) exit(0);
+ fwrite(buf, 1, len, f);
+ if (ferror(f)) exit(0);
+ }
+ }
+
+ fclose(f);
+ close(p[0]);
+ if (_sys_dup(p[1], 1, 0) < 0) {
+ errx(1, "dup() failed when redirecting");
+ }
+ }
+
+ for (struct builtin *iter = builtins; iter->name; iter++) {
+ if (!strcmp(argv[0], iter->name)) {
+ setprogname(argv[0]);
+ iter->fn(argc, argv);
+ exit(0);
+ }
+ }
+
+ execp(argv);
+ if (errno == EINVAL) {
+ errx(1, "%s isn't a valid executable", argv[0]);
+ } else {
+ errx(1, "unknown command: %s", argv[0]);
+ }
+}
+
+static void run(char *cmd) {
+#define ARGV_MAX 16
+ char *argv[ARGV_MAX];
+ struct redir redir;
+ int argc = parse(cmd, argv, ARGV_MAX, &redir);
+ if (argc < 0) {
+ warn("parsing error");
+ } else {
+ run_args(argc, argv, &redir);
+ }
+}
+
+int main(int argc, char **argv) {
+ static char buf[256];
+ FILE *f = stdin;
+
+ if (argc > 1) {
+ f = fopen(argv[1], "r");
+ if (!f) {
+ err(1, "couldn't open %s", argv[1]);
+ return 1;
+ }
+ }
+
+ for (;;) {
+ if (f == stdin) {
+ printf("%s $ ", getcwd(buf, sizeof buf));
+ }
+ if (!fgets(buf, 256, f)) {
+ return 0;
+ }
+ run(buf);
+ }
+}
diff --git a/src/cmd/shell/shell.h b/src/cmd/shell/shell.h
new file mode 100644
index 0000000..050e704
--- /dev/null
+++ b/src/cmd/shell/shell.h
@@ -0,0 +1,11 @@
+#pragma once
+#include <stdbool.h>
+#include <stddef.h>
+
+struct redir {
+ const char *stdout;
+ bool append;
+};
+
+int parse(char *s, char **argv, size_t argvlen, struct redir *redir);
+void run_args(int argc, char **argv, struct redir *redir);
--
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