major rewrite, which fixes starvation issues

.gitignore

@@ -1,3 +1,4 @@
 *~
 *.o
 *.elf
+sh_elf.c

Makefile

@@ -14,37 +14,39 @@
 # along with this program; see the file COPYING. If not see
 # <http://www.gnu.org/licenses/>.
 
-ifndef PS5_PAYLOAD_SDK
-    $(error PS5_PAYLOAD_SDK is undefined)
-endif
-
 PS5_HOST ?= ps5
 PS5_PORT ?= 9021
 
-ELF := shsrv.elf
-
-CC := $(PS5_PAYLOAD_SDK)/host/x86_64-ps5-payload-cc
-LD := $(PS5_PAYLOAD_SDK)/host/x86_64-ps5-payload-ld
+ifdef PS5_PAYLOAD_SDK
+    include $(PS5_PAYLOAD_SDK)/make/x86_64-ps5-payload.inc
+else
+    $(error PS5_PAYLOAD_SDK is undefined)
+endif
 
-CFLAGS := -Wall -Werror -g
+CFLAGS := -Wall
 LDADD  := -lSceLibcInternal -lkernel_sys
 
-OBJS := main.o shell.o elfldr.o pt.o
 
-COMMANDS := $(wildcard commands/*.c)
-COMMANDS := $(COMMANDS:.c=.o)
+all: shsrv.elf sh.elf
 
+shsrv.o: sh_elf.c
 
-all: $(ELF)
+bundle.o: commands/env_elf.c commands/ls_elf.c commands/ps_elf.c
 
 %.o: %.c
-	$(CC) -c $(CFLAGS) -o $@ $^
+	$(CC) -c $(CFLAGS) -o $@ $<
+
+shsrv.elf: shsrv.o elfldr.o pt.o
+	$(LD) -o $@ $^ $(LDADD)
 
-$(ELF): $(COMMANDS) $(OBJS)
+sh.elf: sh.o builtin.o bundle.o elfldr.o pt.o
 	$(LD) -o $@ $^ $(LDADD)
 
+sh_elf.c: sh.elf
+	xxd -i $^ > $@
+
 clean:
-	rm -f *.o *.elf $(COMMANDS)
+	rm -f *.o *.elf
 
-test: $(ELF)
+test: shsrv.elf
 	nc -q0 $(PS5_HOST) $(PS5_PORT) < $^

builtin.c

@@ -0,0 +1,305 @@
+/* Copyright (C) 2024 John Törnblom
+
+This program is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3, or (at your option) any
+later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; see the file COPYING. If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <sys/stat.h>
+
+#include <ps5/kernel.h>
+
+#include "builtin.h"
+
+
+#define ispathsep(ch) ((ch) == '/' || (ch) == '\\')
+#define iseos(ch)     ((ch) == '\0')
+#define ispathend(ch) (ispathsep(ch) || iseos(ch))
+
+
+/**
+ * Map names of builtin commands.
+ **/
+typedef struct builtin_map {
+  const char    *name;
+  builtin_cmd_t *cmd;
+} builtin_map_t;
+
+
+/**
+ * Return the current working directory of the calling process.
+ **/
+static char*
+get_workdir(void) {
+  return getenv("PWD");
+}
+
+
+/**
+ * Normalize a path.
+ **/
+static char*
+normpath(const char *in, char *buf, size_t bufsize) {
+  char *pos[PATH_MAX];
+  char **top = pos;
+  char *head = buf;
+  int isabs = ispathsep(*in);
+
+  if(isabs && bufsize) {
+    *buf++ = '/';
+    bufsize--;
+  }
+
+  *top++ = buf;
+
+  while(!iseos(*in)) {
+    while(ispathsep(*in)) {
+      ++in;
+    }
+
+    if(iseos(*in)) {
+      break;
+    }
+
+    if(memcmp(in, ".", 1) == 0 && ispathend(in[1])) {
+      ++in;
+      continue;
+    }
+
+    if(memcmp(in, "..", 2) == 0 && ispathend(in[2])) {
+      in += 2;
+
+      if(top != pos + 1) {
+	buf = *--top;
+
+      } else if(isabs) {
+	buf = top[-1];
+
+      } else {
+	strncpy(buf, "../", bufsize);
+	buf += 3;
+	bufsize -= 3;
+      }
+
+      continue;
+    }
+
+    if(top - pos >= PATH_MAX) {
+      return NULL;
+    }
+
+    *top++ = buf;
+
+    while(!ispathend(*in) && bufsize) {
+      *buf++ = *in++;
+      bufsize--;
+    }
+
+    if(ispathsep(*in) && bufsize) {
+      *buf++ = '/';
+      bufsize--;
+    }
+  }
+
+  *buf = '\0';
+
+  if(*head == '\0') {
+    strcpy(head, "./");
+  }
+
+  return head;
+}
+
+
+/**
+ * Return an absolute path.
+ **/
+static char *
+abspath(const char *relpath) {
+  char buf[PATH_MAX];
+
+  if(relpath[0] == '/') {
+    strncpy(buf, relpath, sizeof(buf));
+  } else {
+    snprintf(buf, sizeof(buf), "%s/%s", get_workdir(), relpath);
+  }
+
+  char *ap = malloc(PATH_MAX);
+  return normpath(buf, ap, PATH_MAX);
+}
+
+
+/**
+ * 
+ **/
+static int
+main_cd(int argc, char **argv) {
+  char *old = strdup(getenv("PWD"));
+  char *new = NULL;
+  int err = 0;
+
+  if(argc <= 1) {
+    new = getenv("HOME");
+  } else if (!strcmp(argv[1], "-")) {
+    new = getenv("OLDPWD");
+  } else {
+    new = argv[1];
+  }
+
+  if(!new[0]) {
+    new = "/";
+  }
+
+  new = abspath(new);
+
+  if((err=chdir(new))) {
+    perror(new);
+  } else {
+    setenv("PWD", new, 1);
+    setenv("OLDPWD", old, 1);
+  }
+
+  free(old);
+  free(new);
+
+  return 0;
+}
+
+
+/**
+ * Change the root directory.
+ **/
+static int
+main_chroot(int argc, char **argv) {
+  pid_t pid = getpid();
+  uint64_t authid;
+  char *path;
+  int err;
+
+  if(argc <= 1) {
+    fprintf(stderr, "%s: missing operand\n", argv[0]);
+    return EXIT_FAILURE;
+  }
+
+  if(!(path=abspath(argv[1]))) {
+    perror(argv[0]);
+    return EXIT_FAILURE;
+  }
+
+  authid = kernel_get_ucred_authid(pid);
+  kernel_set_ucred_authid(pid, 0x4800000000000007l);
+  err = chroot(path);
+  kernel_set_ucred_authid(pid, authid);
+
+  free(path);
+
+  if(err) {
+    perror(argv[1]);
+    return EXIT_FAILURE;
+  }
+
+  return EXIT_SUCCESS;
+}
+
+
+/**
+ * Terminate the process.
+ **/
+static int
+main_exit(int argc, char** argv) {
+  int rc = 0;
+
+  if(argc > 1) {
+    rc = atoi(argv[1]);
+  }
+
+  exit(rc);
+
+  return EXIT_FAILURE;
+}
+
+
+/**
+ * Set export attribute for shell variables.
+ **/
+static int
+main_export(int argc, char **argv) {
+  char *name;
+  char *val;
+  char *sep;
+
+  if(argc < 2 || !(sep=strstr(argv[1], "="))) {
+    printf("usage: %s NAME=value\n", argv[0]);
+    return EXIT_FAILURE;
+  }
+
+  name = argv[1];
+  *sep = 0;
+  val = sep+1;
+
+  if(setenv(name, val, 1)) {
+    perror(argv[0]);
+    return EXIT_FAILURE;
+  }
+
+  return EXIT_SUCCESS;
+}
+
+
+/**
+ * Replace the current process image with a new one.
+ **/
+static int
+main_exec(int argc, char** argv) {
+  if(argc <= 1) {
+    return EXIT_FAILURE;
+  }
+
+  argv[argc] = NULL;
+  execvp(argv[1], (char **) argv + 1);
+  perror(argv[1]);
+
+  return EXIT_FAILURE;
+}
+
+
+/**
+ * Lookup table for builtin commands.
+ **/
+static builtin_map_t map[] = {
+  {"cd", main_cd},
+  {"chroot", main_chroot},
+  {"exec", main_exec},
+  {"exit", main_exit},
+  {"export", main_export},
+};
+
+
+builtin_cmd_t*
+builtin_find_cmd(const char* name) {
+  for(int i=0; i<sizeof(map)/sizeof(map[0]); i++) {
+    if(!strcmp(name, map[i].name)) {
+      return map[i].cmd;
+    }
+  }
+
+  return NULL;
+}

commands/_common.h → builtin.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2021 John Törnblom
+/* Copyright (C) 2024 John Törnblom
 
 This program is free software; you can redistribute it and/or modify it
 under the terms of the GNU General Public License as published by the
@@ -16,10 +16,15 @@ along with this program; see the file COPYING. If not, see
 
 #pragma once
 
-#include <stdint.h>
-#include <stdlib.h>
 
-char* get_workdir(void);
-char* normpath(const char *path);
-char* abspath(const char *relpath);
-void hexdump(void *data, size_t size);
+/**
+ * Prototype for builtin commands.
+ **/
+typedef int (builtin_cmd_t)(int argc, char **argv);
+
+
+/**
+ * Find a builtin command by its name.
+ **/
+builtin_cmd_t* builtin_find_cmd(const char* name);
+