feat(README.md): cosmopolitan libc "tutorial"

Added support for cosmopolitan libc.
Simply do `make COSMO=yes` and you'll get feuille.com, a working
αcτµαlly pδrταblε εxεcµταblε pastebin server.

+ version bump.

.gitignore

@@ -1,4 +1,8 @@
 *.o
 
+cosmopolitan
+
 feuille
+feuille.com
+
 cgi/feuille.cgi

Makefile

@@ -4,11 +4,13 @@
 
 include config.mk
 
-TARGET = feuille
+TARGET         = feuille.com
+TARGET$(COSMO) = feuille
+
 SRC = feuille.c util.c server.c bin.c
 OBJ = $(SRC:%.c=%.o)
 
-all: $(TARGET) $(TARGET).1 cgi
+all: $(TARGET) feuille.1 cgi
 
 run: $(TARGET)
 	./$(TARGET)
@@ -18,10 +20,10 @@ clean:
 	@rm -f $(OBJ)
 
 distclean:
-	@printf "%-8s $(TARGET) $(OBJ)\n" "rm"
-	@rm -f $(TARGET) $(OBJ)
+	@printf "%-8s feuille feuille.com $(OBJ)\n" "rm"
+	@rm -f feuille feuille.com $(OBJ)
 
-install: $(TARGET) $(TARGET).1
+install: $(TARGET) feuille.1
 	@echo "installing executable file to $(PREFIX)/bin"
 	@mkdir -p   "$(PREFIX)/bin"
 	@cp -f $(TARGET) "$(PREFIX)/bin"
@@ -29,34 +31,53 @@ install: $(TARGET) $(TARGET).1
 
 	@echo "installing manpage to $(MAN)/man1"
 	@mkdir -p $(MAN)/man1
-	@cp -f $(TARGET).1 $(MAN)/man1
-	@chmod 644 $(MAN)/man1/$(TARGET).1
+	@cp -f feuille.1 $(MAN)/man1
+	@chmod 644 $(MAN)/man1/feuille.1
 
-uninstall: $(PREFIX)/bin/$(TARGET) $(MAN)/man1/$(TARGET).1
+uninstall: $(PREFIX)/bin/$(TARGET) $(MAN)/man1/feuille.1
 	@echo "removing executable file from $(PREFIX)/bin"
 	@rm -f "$(PREFIX)/bin/$(TARGET)"
 
 	@echo "removing manpage from $(MAN)/man1"
-	@rm -f $(MAN)/man1/$(TARGET).1
+	@rm -f $(MAN)/man1/feuille.1
 
-$(TARGET): $(OBJ)
-	@printf "%-8s $(OBJ) -o $@\n" "$(CC)"
-	@$(CC) $(LDFLAGS) $(OBJ) -o $@
+feuille.1: feuille.1.md config.mk
+	@printf "%-8s feuille.1.md -o feuille.1\n" "pandoc"
+	@sed "s/{VERSION}/$(VERSION)/g" feuille.1.md | pandoc -s -t man -o feuille.1
 
-$(TARGET).1: $(TARGET).1.md config.mk
-	@printf "%-8s $(TARGET).1.md -o $@\n" "pandoc"
-	@sed "s/{VERSION}/$(VERSION)/g" $(TARGET).1.md | pandoc -s -t man -o $@
+feuille: $(OBJ)
+	@printf "%-8s $(OBJ) -o feuille\n" "$(CC)"
+	@$(CC) $(OBJ) -o feuille $(LDFLAGS)
 
+# cosmopolitan libc
+feuille.com: cosmopolitan feuille
+	@printf "%-8s feuille -o feuille.com\n" "objcopy"
+	@objcopy -S -O binary feuille feuille.com
+
+cosmopolitan:
+	@if [ ! -d cosmopolitan ]; then                                                                 \
+	     printf "%-8s https://justine.lol/cosmopolitan/cosmopolitan-amalgamation-2.2.zip\n" "curl" ;\
+	     curl -sO "https://justine.lol/cosmopolitan/cosmopolitan-amalgamation-2.2.zip"             ;\
+                                                                                                    \
+	     printf "%-8s cosmopolitan-amalgamation-2.2.zip\n" "unzip"                                 ;\
+	     unzip -qf cosmopolitan-amalgamation-2.2.zip -d cosmopolitan                               ;\
+                                                                                                    \
+	     rm -rf cosmopolitan-amalgamation-*                                                        ;\
+	fi
+
+# CGI script
 ADDR = 127.0.0.1
 PORT = 9999
 
 cgi: cgi/feuille.cgi
 
 cgi/feuille.cgi: cgi/feuille.cgi.c
-	@printf "%-8s cgi/feuille.cgi.c -o $@\n" "$(CC)"
-	@$(CC) $(CFLAGS) $(LDFLAGS) -static -DADDR=\"$(ADDR)\" -DPORT=$(PORT) cgi/feuille.cgi.c -o $@
+	@printf "%-8s cgi/feuille.cgi.c -o cgi/feuille.cgi\n" "$(CC)"
+	@$(CC) cgi/feuille.cgi.c -o cgi/feuille.cgi -std=c99 -O3 -static -Wall -Wextra \
+                                                -DADDR=\"$(ADDR)\" -DPORT=$(PORT)  \
+                                                $(INCS) $(LIBS)
 
 .SUFFIXES: .c .o
 .c.o:
 	@printf "%-8s $<\n" "$(CC)"
-	@$(CC) $(CFLAGS) -c $<
+	@$(CC) -c $< $(CFLAGS)

README.md

@@ -159,6 +159,7 @@ That sould be it. Have fun!
 * Works on nearly all POSIX-compliant OSes
 * Can be run in the background and as a service
 * IPv6-enabled
+* Now with 100% more (Cosmopolitan libc)[http://justine.lol/cosmopolitan/] support!
 
 ## Installation
 
@@ -194,6 +195,13 @@ $ make
 $ sudo make install
 ```
 
+You can also build using the
+(Cosmopolitan libc)[http://justine.lol/cosmopolitan/], which will
+make an executable capable of running on Linux, OpenBSD, FreeBSD,
+Mac... out of the box. To do so, build with the `COSMO` flag.
+It will produce `feuille` and `feuille.com`, the former being the
+debug binary, and the former the portable one.
+
 If you wish to make a debug build, you can set `DEBUG` to whatever
 comes to your mind.
 
@@ -201,7 +209,7 @@ You can also set `CC` to the compiler of your liking, like `clang` or
 `pcc`.
 
 ```console
-$ make DEBUG=yes CC=clang
+$ make COSMO=y DEBUG=y CC=clang
 ```
 
 In order to compile CGI script(s), run:

arg.h

@@ -34,8 +34,11 @@
 #ifndef _ARG_H_
 #define _ARG_H_
 
+#ifndef COSMOPOLITAN
 #include <stdlib.h>
 #include <stddef.h>
+#endif
+
 extern char *argv0;
 
 /* use main(int argc, char *argv[]) */

bin.c

@@ -13,11 +13,13 @@
 
 #include "bin.h"
 
+#ifndef COSMOPOLITAN
 #include <errno.h>    /* for errno                                      */
 #include <stdio.h>    /* for NULL, fclose, fopen, fputs, snprintf, FILE */
 #include <stdlib.h>   /* for calloc, free, malloc, rand, realloc        */
 #include <string.h>   /* for strlen                                     */
 #include <unistd.h>   /* for access, F_OK                               */
+#endif
 
 #include "feuille.h"  /* for Settings, settings                         */
 

config.mk

@@ -1,5 +1,5 @@
 # feuille version
-VERSION = 1.19.5
+VERSION = 2.1.0
 
 # paths (customize them to fit your system)
 PREFIX = /usr/local
@@ -17,13 +17,28 @@ LIBS = -L/usr/lib -lc
 # compiler
 CC = cc
 
-# debug build
-CFLAGS  = -g -std=c99 -Wall -Wextra -Wpedantic -Wno-sign-compare -DVERSION=\"$(VERSION)\" -DDEBUG $(INCS)
-LDFLAGS = -g $(LIBS)
+# cosmopolitan libc flags
+CCFLAGS  = -std=c99 -nostdinc -fno-pie -fno-omit-frame-pointer \
+           -mno-tls-direct-seg-refs -mno-red-zone              \
+           -DVERSION=\"$(VERSION)\" -DCOSMOPOLITAN             \
+           -I. -include cosmopolitan/cosmopolitan.h
 
-# release build
-CFLAGS$(DEBUG)  = -std=c99 -Wall -Wextra -Wno-sign-compare -DVERSION=\"$(VERSION)\" -O3 $(INCS)
-LDFLAGS$(DEBUG) = -s $(LIBS)
+CLDFLAGS = -std=c99 -static -nostdlib -fno-pie -fno-omit-frame-pointer \
+           -mno-tls-direct-seg-refs -mno-red-zone                      \
+           -fuse-ld=bfd -Wl,-T,cosmopolitan/ape.lds -Wl,--gc-sections  \
+           cosmopolitan/crt.o cosmopolitan/ape-no-modify-self.o cosmopolitan/cosmopolitan.a
+
+# standard libc flags
+CCFLAGS$(COSMO)  = -std=c99 -DVERSION=\"$(VERSION)\" $(INCS)
+CLDFLAGS$(COSMO) = $(LIBS)
+
+# debug flags
+CFLAGS  = -g -Wall -Wextra -Wno-sign-compare -DDEBUG $(CCFLAGS)
+LDFLAGS = -g $(CLDFLAGS)
+
+# release flags
+CFLAGS$(DEBUG)  = -O3 -Wall -Wextra -Wno-sign-compare $(CCFLAGS)
+LDFLAGS$(DEBUG) = -s $(CLDFLAGS)
 
 # static build (uncomment)
 #LD_FLAGS += -static

feuille.1

@@ -14,7 +14,7 @@
 . ftr VB CB
 . ftr VBI CBI
 .\}
-.TH "feuille" "1" "November 2022" "feuille 1.19.5" ""
+.TH "feuille" "1" "November 2022" "feuille 2.1.0" ""
 .hy
 .SH NAME
 .PP

feuille.c

@@ -15,6 +15,7 @@
 
 #include "feuille.h"
 
+#ifndef COSMOPOLITAN
 #include <errno.h>     /* for errno, ERANGE, EAGAIN, EFBIG, ENOENT              */
 #include <grp.h>       /* for initgroups                                        */
 #include <limits.h>    /* for USHRT_MAX, ULONG_MAX, CHAR_MAX, PATH_MAX, UCHA... */
@@ -29,6 +30,7 @@
 #include <syslog.h>    /* for syslog, openlog, LOG_WARNING, LOG_NDELAY, LOG_... */
 #include <time.h>      /* for time                                              */
 #include <unistd.h>    /* for getuid, access, chdir, chown, chroot, close       */
+#endif
 
 #include "arg.h"       /* for EARGF, ARGBEGIN, ARGEND                           */
 #include "bin.h"       /* for create_url, generate_id, write_paste              */
@@ -93,6 +95,12 @@ void accept_loop(int server)
     /* accept loop */
     int connection;
     while ((connection = accept_connection(server))) {
+        /* check if the socket is invalid */
+        if (connection == -1) {
+            error("error while accepting incoming connection: %s", strerror(errno));
+            continue;
+        }
+
         verbose(1, "--- new incoming connection. connection ID: %d:%d ---", pid, time(0));
 
         unsigned long paste_size = 0;
@@ -342,7 +350,6 @@ int main(int argc, char *argv[])
         gid = user->pw_gid;
 
     } else {
-        puts("");
         syslog(LOG_WARNING, "running as non-root user.");
         syslog(LOG_WARNING, "`chroot' and user switching have been disabled.");
         puts("");
@@ -382,15 +389,18 @@ int main(int argc, char *argv[])
         if (setgid(gid) != 0 || getgid() != gid)
             die(1, "could not switch to group for user `%s'.\n", settings.user);
 
+        #ifndef COSMOPOLITAN
+        /* initgroups doesn't work on cosmopolitan libc yet */
         if (initgroups(settings.user, gid) != 0)
             die(1, "could not initialize other groups for user `%s'.\n", settings.user);
+        #endif
 
         /* switching user */
         if (setuid(uid) != 0 || getuid() != uid)
             die(1, "could not switch to user `%s'.\n", settings.user);
     }
 
-#ifdef __OpenBSD__
+#if defined __OpenBSD__ || defined COSMOPOLITAN
     /* OpenBSD-only security measures */
     pledge("proc stdio rpath wpath cpath inet", "stdio rpath wpath cpath inet");
 #endif

server.c

@@ -13,6 +13,7 @@
 
 #include "server.h"
 
+#ifndef COSMOPOLITAN
 #include <arpa/inet.h>   /* for inet_pton                                      */
 #include <errno.h>       /* for errno, EAGAIN, EFBIG, ENOENT                   */
 #include <netinet/in.h>  /* for htons, sockaddr_in, sockaddr_in6, IPPROTO_IPV6 */
@@ -24,6 +25,7 @@
 #include <sys/socket.h>  /* for setsockopt, bind, socket, SOL_SOCKET, AF_INET  */
 #include <sys/time.h>    /* for timeval                                        */
 #include <unistd.h>      /* for close                                          */
+#endif
 
 #include "feuille.h"     /* for Settings, settings                             */
 #include "util.h"        /* for verbose                                        */
@@ -103,19 +105,14 @@ int initialize_server()
         if (setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &(int){ 1 }, sizeof(int)) < 0)
             return -1;
 
-#ifndef __OpenBSD__
         /* Enable dual-stack mode on supported platforms */
         verbose(3, "  IPV6_V6ONLY...");
-        if (setsockopt(server, IPPROTO_IPV6, IPV6_V6ONLY, &ipv6_only, sizeof(ipv6_only)) < 0)
-            return -1;
-#else
-        if (ipv6_only == 0) {
-            puts("");
-            syslog(LOG_WARNING, "dual-stack mode is disabled on OpenBSD.");
+
+        if (setsockopt(server, IPPROTO_IPV6, IPV6_V6ONLY, &ipv6_only, sizeof(ipv6_only)) < 0) {
+            syslog(LOG_WARNING, "dual-stack mode is disabled on your platform.");
             syslog(LOG_WARNING, "feuille will only listen on the `::' IPv6 address.");
             puts("");
         }
-#endif
 
         /* bind address and port */
         verbose(3, "binding address on the socket...");
@@ -141,9 +138,14 @@ int initialize_server()
  */
 int accept_connection(int socket)
 {
+    /* only needed for cosmopolitan libc */
+    /* we don't do anything with this struct yet */
+    struct sockaddr_in address;
+    int addrlen = sizeof(address);
+
     /* accept the connection */
     /* TODO: maybe retrieve IP address for logging? *maybe* */
-    int connection = accept(socket, (struct sockaddr *)NULL, NULL);
+    int connection = accept(socket, (struct sockaddr*)&address, (socklen_t*)&addrlen);
 
     /* set the timeout for the connection */
     struct timeval timeout = { settings.timeout, 0 };

util.c

@@ -15,11 +15,13 @@
 
 #include "util.h"
 
+#ifndef COSMOPOLITAN
 #include <stdarg.h>   /* for va_end, va_list, va_start                     */
 #include <stdio.h>    /* for snprintf, vsnprintf, vfprintf, BUFSIZ, stderr */
 #include <stdlib.h>   /* for exit                                          */
 #include <syslog.h>   /* for syslog, LOG_DEBUG, LOG_ERR                    */
 #include <unistd.h>   /* for getpid                                        */
+#endif
 
 #include "feuille.h"  /* for Settings, settings                            */