Initial revision

1 files changed, 257 insertions, 0 deletions

diff --git a/cgi.c b/cgi.c
new file mode 100644
index 0000000..809117a
--- /dev/null
+++ b/cgi.c
@@ -0,0 +1,257 @@
+/*
+ * started writing (limited) CGI support for webfsd
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include "httpd.h"
+
+/* ---------------------------------------------------------------------- */
+
+extern char **environ;
+
+static char *env_wlist[] = {
+    "PATH", "HOME",
+    NULL
+};
+
+static void env_add(struct strlist **list, char *name, char *value)
+{
+    char *line;
+
+    line = malloc(strlen(name) + strlen(value) + 2);
+    sprintf(line,"%s=%s",name,value);
+    if (debug)
+	fprintf(stderr,"cgi: env %s\n",line);
+    list_add(list,line,1);
+}
+
+static char**
+env_convert(struct strlist *list)
+{
+    struct strlist *elem;
+    char **env;
+    int i;
+
+    for (i = 2, elem = list; NULL != elem; elem = elem->next)
+	i++;
+    env = malloc(sizeof(char*)*i);
+    for (i = 0, elem = list; NULL != elem; elem = elem->next)
+	env[i++] = elem->line;
+    env[i++] = NULL;
+    return env;
+}
+
+static void env_copy(struct strlist **list)
+{
+    int i,j,l;
+
+    for (i = 0; environ[i] != NULL; i++) {
+	for (j = 0; env_wlist[j] != NULL; j++) {
+	    l = strlen(env_wlist[j]);
+	    if (0 == strncmp(environ[i],env_wlist[j],l) &&
+		environ[i][l] == '=') {
+		env_add(list,env_wlist[j],environ[i]+l+1);
+		break;
+	    }
+	}
+    }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void
+cgi_request(struct REQUEST *req)
+{
+    struct sockaddr_storage addr;
+    struct strlist *env = NULL, *item;
+    char host[65],serv[9];
+    char filename[1024], *h, *argv[2], envname[128];
+    int pid,p[2],i,length;
+
+    if (debug)
+	fprintf(stderr,"%03d: is cgi request\n",req->fd);
+    if (-1 == pipe(p)) {
+	mkerror(req,500,0);
+	return;
+    }
+    pid = fork();
+    switch (pid) {
+    case -1:
+	/* error */
+	if (debug)
+	    perror("fork");
+	mkerror(req,500,0);
+	return;
+    case 0:
+	break;
+    default:
+	/* parent - webfsd */
+	close(p[1]);
+	req->cgipid  = pid;
+	req->cgipipe = p[0];
+	req->state   = STATE_CGI_HEADER;
+	close_on_exec(req->cgipipe);
+	fcntl(req->cgipipe,F_SETFL,O_NONBLOCK);
+	return;
+    }
+
+    /* -------- below is the child process (cgi) code -------- */
+
+    /* lookup local socket (before it gets closed) */
+    length = sizeof(addr);
+    getsockname(req->fd,(struct sockaddr*)&addr,&length);
+    getnameinfo((struct sockaddr*)&addr,length,host,64,serv,8,
+		NI_NUMERICHOST | NI_NUMERICSERV);
+    
+    /* setup file descriptors */
+    dup2(p[1],1); /* pipe -> stdout */
+    if (have_tty) {
+	int devnull = open("/dev/null",O_RDWR);
+	dup2(devnull,0); /* stdin  */
+	dup2(devnull,2); /* stderr */
+	close(devnull);
+    } else {
+	/* nothing -- already attached to /dev/null */
+    }
+    close_on_exec(p[0]);
+    close_on_exec(p[1]);
+
+    /* setup environment */
+    env_copy(&env);
+
+    env_add(&env,"DOCUMENT_ROOT",doc_root);
+    env_add(&env,"GATEWAY_INTERFACE","CGI/1.1");
+    env_add(&env,"QUERY_STRING",req->query);
+    env_add(&env,"REQUEST_URI",req->uri);
+    env_add(&env,"REMOTE_ADDR",req->peerhost);
+    env_add(&env,"REMOTE_PORT",req->peerserv);
+    env_add(&env,"REQUEST_METHOD",req->type);
+    env_add(&env,"SERVER_ADMIN","root@localhost");
+    env_add(&env,"SERVER_NAME",server_host);
+    env_add(&env,"SERVER_PROTOCOL","HTTP/1.1");
+    env_add(&env,"SERVER_SOFTWARE",server_name);
+    env_add(&env,"SERVER_ADDR",host);
+    env_add(&env,"SERVER_PORT",serv);
+
+    for (item = req->header; NULL != item; item = item->next) {
+	strcpy(envname,"HTTP_");
+	if (1 != sscanf(item->line,"%120[-A-Za-z]: %n",envname+5,&length))
+	    continue;
+	for (i = 0; envname[i]; i++) {
+	    if (isalpha(envname[i]))
+		envname[i] = toupper(envname[i]);
+	    if ('-' == envname[i])
+		envname[i] = '_';
+	}
+	env_add(&env,envname,item->line+length);
+    }
+
+    h = req->path + strlen(cgipath);
+    h = strchr(h,'/');
+    if (h) {
+	env_add(&env,"PATH_INFO",h);
+	*h = 0;
+    } else {
+	env_add(&env,"PATH_INFO","");
+    }
+    env_add(&env,"SCRIPT_NAME",req->path);
+    snprintf(filename,sizeof(filename)-1,"%s%s",doc_root,req->path);
+    env_add(&env,"SCRIPT_FILENAME",filename);
+
+    /* start cgi app */
+    argv[0] = filename;
+    argv[1] = NULL;
+    execve(filename,argv,env_convert(env));
+
+    /* exec failed ... */
+    printf("Content-Type: text/plain\n"
+	   "\n"
+	   "execve %s: %s\n",
+	   filename,strerror(errno));
+    exit(1);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void
+cgi_read_header(struct REQUEST *req)
+{
+    struct strlist  *list = NULL;
+    char            *h,*next,*status = NULL;
+    int             rc;
+
+ restart:
+    rc = read(req->cgipipe, req->cgibuf+req->cgilen, MAX_HEADER-req->cgilen);
+    switch (rc) {
+    case -1:
+	if (errno == EAGAIN)
+	    return;
+	if (errno == EINTR)
+	    goto restart;
+	/* fall through */
+    case 0:
+	mkerror(req,500,0);
+	return;
+    default:
+	req->cgilen += rc;
+	req->cgibuf[req->cgilen] = 0;
+    }
+
+    /* header complete ?? */
+    if (NULL != (h = strstr(req->cgibuf,"\r\n\r\n")) ||
+	NULL != (h = strstr(req->cgibuf,"\n\n"))) {
+
+	/* parse cgi header */
+	for (h = req->cgibuf;; h = next) {
+	    next = strstr(h,"\n");
+	    next[0] = 0;
+	    if (next[-1] == '\r')
+		next[-1] = 0;
+	    next++;
+	    
+	    if (0 == strlen(h))
+		break;
+	    if (debug)
+		fprintf(stderr,"%03d: cgi: hdr %s\n",req->fd,h);
+	    if (0 == strncasecmp(h,"Status: ",8)) {
+		status = h+8;
+		if (debug)
+		    fprintf(stderr,"%03d: cgi: status %s\n",req->fd,status);
+		continue;
+	    }
+	    if (0 == strncasecmp(h,"Server:",7)         ||
+		0 == strncasecmp(h,"Connection:",11)    ||
+		0 == strncasecmp(h,"Accept-Ranges:",14) ||
+		0 == strncasecmp(h,"Date:",5))
+		/* webfsd adds them -- filter out */
+		continue;
+	    list_add(&list,h,0);
+	}
+	mkcgi(req, status ? status : "200 OK", list);
+	list_free(&list);
+	req->cgipos = next - req->cgibuf;
+	if (debug)
+	    fprintf(stderr,"%03d: cgi: pos=%d len=%d\n",req->fd,
+		    req->cgipos, req->cgilen);
+	return;
+    }
+
+    if (req->cgilen == MAX_HEADER) {
+	mkerror(req,400,0);
+	return;
+    }
+    return;
+}