Fix traversal handling, add selector and traversal to CGI environment. - geomyidae - A small C-based gopherd. (gopher://bitreich.org/1/scm/geomyidae)

git clone git://r-36.net/geomyidae

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---

commit a291bc8c99309fcbfd1a7688988ba60a2e5bf042

parent b12a77acd24fc170b1ad047986ffaf13592fb326

Author: Christoph Lohmann <20h@r-36.net>

Date:   Sat, 22 Jul 2023 15:28:45 +0200

Fix traversal handling, add selector and traversal to CGI environment.

* Add raw selector to CGI scripts.
* Add traversal to CGI scripts.
* Add both to manpages.

Diffstat:
  M geomyidae.8                         |       9 ++++++---
  M handlr.c                            |      56 ++++++++++++++++----------------
  M handlr.h                            |      18 +++++++++++-------
  M ind.c                               |      21 +++++----------------
  M ind.h                               |       4 ++--
  M main.c                              |     102 +++++++++++++++----------------

6 files changed, 102 insertions(+), 108 deletions(-)
---

diff --git a/geomyidae.8 b/geomyidae.8

@@ -352,9 +352,11 @@ executable.[d]cgi $search $arguments $host $port
 where
 .Bd -literal -offset indent
 search = query string (type 7) or "" (type 0)
-arguments = string after "?" in the path, the remaining path or ""
+arguments = string behind "?" in selector or ""
 host = server's hostname ("localhost" by default)
 port = server's port ("70" by default)
+traversal = remaining path from path traversal
+selector = raw selector
 .Ed
 .Pp
 All terms are tab-separated (per gopher protocol) which can cause some
@@ -377,8 +379,9 @@ GATEWAY_INTERFACE = `CGI/1.1'
 PATH_INFO = script which is executed
 PATH_TRANSLATED = absolute path with script which is executed
 QUERY_STRING = arguments (See above.)
-SELECTOR = arguments (For backwards compatibility.)
-REQUEST = arguments (For backwards compatibility.)
+SELECTOR = raw selector
+REQUEST = raw selector
+TRAVERSAL = traversel (See above.)
 REMOTE_ADDR = IP of the client
 REMOTE_HOST = REMOTE_ADDR
 REQUEST_METHOD = `GET'

diff --git a/handlr.c b/handlr.c

@@ -24,7 +24,8 @@
 
 void
 handledir(int sock, char *path, char *port, char *base, char *args,
-                char *sear, char *ohost, char *chost, char *bhost, int istls)
+                char *sear, char *ohost, char *chost, char *bhost, int istls,
+                char *sel, char *traverse)
 {
         char *pa, *file, *e, *par;
         struct dirent **dirent;
@@ -35,12 +36,8 @@ handledir(int sock, char *path, char *port, char *base, char *args,
         USED(args);
         USED(sear);
         USED(bhost);
-
-        printf("handledir:\n");
-        printf("sock = %d; path = %s; port = %s; base = %s; args = %s;\n",
-                        sock, path, port, base, args);
-        printf("sear = %s; ohost = %s; chost = %s; bhost = %s; istls = %d;\n",
-                        sear, ohost, chost, bhost, istls);
+        USED(sel);
+        USED(traverse);
 
         pa = xstrdup(path);
 
@@ -70,7 +67,6 @@ handledir(int sock, char *path, char *port, char *base, char *args,
                                         pa,
                                         pa[strlen(pa)-1] == '/'? "" : "/",
                                         dirent[i]->d_name);
-                        printf("handledir: smprintf file = %s\n", file);
                         if (stat(file, &st) >= 0 && S_ISDIR(st.st_mode))
                                 type = gettype("index.gph");
                         ret = dprintf(sock,
@@ -93,7 +89,8 @@ handledir(int sock, char *path, char *port, char *base, char *args,
 
 void
 handlegph(int sock, char *file, char *port, char *base, char *args,
-                char *sear, char *ohost, char *chost, char *bhost, int istls)
+                char *sear, char *ohost, char *chost, char *bhost, int istls,
+                char *sel, char *traverse)
 {
         gphindex *act;
         int i, ret = 0;
@@ -101,12 +98,8 @@ handlegph(int sock, char *file, char *port, char *base, char *args,
         USED(args);
         USED(sear);
         USED(bhost);
-
-        printf("handlegph:\n");
-        printf("sock = %d; file = %s; port = %s; base = %s; args = %s;\n",
-                        sock, file, port, base, args);
-        printf("sear = %s; ohost = %s; chost = %s; bhost = %s; istls = %d;\n",
-                        sear, ohost, chost, bhost, istls);
+        USED(sel);
+        USED(traverse);
 
         act = gph_scanfile(file);
         if (act != NULL) {
@@ -124,7 +117,8 @@ handlegph(int sock, char *file, char *port, char *base, char *args,
 
 void
 handlebin(int sock, char *file, char *port, char *base, char *args,
-                char *sear, char *ohost, char *chost, char *bhost, int istls)
+                char *sear, char *ohost, char *chost, char *bhost, int istls,
+                char *sel, char *traverse)
 {
         int fd;
 
@@ -134,6 +128,8 @@ handlebin(int sock, char *file, char *port, char *base, char *args,
         USED(sear);
         USED(ohost);
         USED(bhost);
+        USED(sel);
+        USED(traverse);
 
         fd = open(file, O_RDONLY);
         if (fd >= 0) {
@@ -145,9 +141,10 @@ handlebin(int sock, char *file, char *port, char *base, char *args,
 
 void
 handlecgi(int sock, char *file, char *port, char *base, char *args,
-                char *sear, char *ohost, char *chost, char *bhost, int istls)
+                char *sear, char *ohost, char *chost, char *bhost, int istls,
+                char *sel, char *traverse)
 {
-        char *script, *path;
+        char *script, *path, *filec;
 
         USED(base);
         USED(port);
@@ -157,9 +154,10 @@ handlecgi(int sock, char *file, char *port, char *base, char *args,
                         sock, file, port, base, args);
         printf("sear = %s; ohost = %s; chost = %s; bhost = %s; istls = %d;\n",
                         sear, ohost, chost, bhost, istls);
+        printf("sel = %s; traverse = %s;\n", sel, traverse);
 
-        path = xstrdup(file);
-        path = dirname(path);
+        filec = xstrdup(file);
+        path = dirname(filec);
         script = path + strlen(path) + 1;
         printf("path = %s\n", path);
         printf("script = %s\n", script);
@@ -180,7 +178,7 @@ handlecgi(int sock, char *file, char *port, char *base, char *args,
                 }
 
                 setcgienviron(script, file, port, base, args, sear, ohost, chost,
-                                bhost, istls);
+                                bhost, istls, sel, traverse);
 
                 if (execl(file, script, sear, args, ohost, port,
                                 (char *)NULL) == -1) {
@@ -192,17 +190,18 @@ handlecgi(int sock, char *file, char *port, char *base, char *args,
                 break;
         default:
                 wait(NULL);
-                free(path);
+                free(filec);
                 break;
         }
 }
 
 void
 handledcgi(int sock, char *file, char *port, char *base, char *args,
-                char *sear, char *ohost, char *chost, char *bhost, int istls)
+                char *sear, char *ohost, char *chost, char *bhost, int istls,
+                char *sel, char *traverse)
 {
         FILE *fp;
-        char *script, *path, *ln = NULL;
+        char *script, *path, *filec, *ln = NULL;
         size_t linesiz = 0;
         ssize_t n;
         int outsocks[2], ret = 0;
@@ -213,12 +212,13 @@ handledcgi(int sock, char *file, char *port, char *base, char *args,
                         sock, file, port, base, args);
         printf("sear = %s; ohost = %s; chost = %s; bhost = %s; istls = %d;\n",
                         sear, ohost, chost, bhost, istls);
+        printf("sel = %s; traverse = %s;\n", sel, traverse);
 
         if (socketpair(AF_LOCAL, SOCK_STREAM, 0, outsocks) < 0)
                 return;
 
-        path = xstrdup(file);
-        path = dirname(path);
+        filec = xstrdup(file);
+        path = dirname(filec);
         script = path + strlen(path) + 1;
 
         if (sear == NULL)
@@ -238,7 +238,7 @@ handledcgi(int sock, char *file, char *port, char *base, char *args,
                 }
 
                 setcgienviron(script, file, port, base, args, sear, ohost, chost,
-                                bhost, istls);
+                                bhost, istls, sel, traverse);
 
                 if (execl(file, script, sear, args, ohost, port,
                                 (char *)NULL) == -1) {
@@ -277,7 +277,7 @@ handledcgi(int sock, char *file, char *port, char *base, char *args,
                 free(ln);
                 fclose(fp);
                 wait(NULL);
-                free(path);
+                free(filec);
                 break;
         }
 }

diff --git a/handlr.h b/handlr.h

@@ -23,7 +23,7 @@
  * base .... base path of geomyidae, never ends in '/', so chroot is ''
  *   Sample: /var/gopher
  * args .... Gives all variable input from the selector in some way.
- *   Sample: /with/dirs////?key=value
+ *   Sample: key=value
  * sear .... search part of request
  *   Sample: search what?
  * ohost ... host of geomyidae (See -h in geomyidae(8))
@@ -34,25 +34,29 @@
  *   Sample: 78.46.175.99
  * istls ... set to 1, if TLS was used for thr request
  *   Sample: 1
+ * sel ..... Gives the raw selector after processing.
+ *   Sample: /get/some/script/with/dirs////?key=value
+ * traversal ..... Gives the raw selector after processing.
+ *   Sample: /with/dirs////
  */
 
 void handledir(int sock, char *path, char *port, char *base, char *args,
                         char *sear, char *ohost, char *chost, char *bhost,
-                        int istls);
+                        int istls, char *sel, char *traverse);
 void handlegph(int sock, char *file, char *port, char *base, char *args,
                         char *sear, char *ohost, char *chost, char *bhost,
-                        int istls);
+                        int istls, char *sel, char *traverse);
 void handlebin(int sock, char *file, char *port, char *base, char *args,
                         char *sear, char *ohost, char *chost, char *bhost,
-                        int istls);
+                        int istls, char *sel, char *traverse);
 void handletxt(int sock, char *file, char *port, char *base, char *args,
                         char *sear, char *ohost, char *chost, char *bhost,
-                        int istls);
+                        int istls, char *sel, char *traverse);
 void handlecgi(int sock, char *file, char *port, char *base, char *args,
                         char *sear, char *ohost, char *chost, char *bhost,
-                        int istls);
+                        int istls, char *sel, char *traverse);
 void handledcgi(int sock, char *file, char *port, char *base, char *args,
                         char *sear, char *ohost, char *chost, char *bhost,
-                        int istls);
+                        int istls, char *sel, char *traverse);
 
 #endif

diff --git a/ind.c b/ind.c

@@ -535,7 +535,8 @@ reverselookup(char *host)
 
 void
 setcgienviron(char *file, char *path, char *port, char *base, char *args,
-                char *sear, char *ohost, char *chost, char *bhost, int istls)
+                char *sear, char *ohost, char *chost, char *bhost, int istls,
+                char *sel, char *traverse)
 {
         /*
          * TODO: Clean environment from possible unsafe environment variables.
@@ -547,26 +548,19 @@ setcgienviron(char *file, char *path, char *port, char *base, char *args,
         setenv("GATEWAY_INTERFACE", "CGI/1.1", 1);
         /* TODO: Separate, if run like rest.dcgi. */
         setenv("PATH_INFO", file, 1);
-        printf("PATH_INFO = %s\n", file);
         setenv("PATH_TRANSLATED", path, 1);
-        printf("PATH_TRANSLATED = %s\n", path);
 
         setenv("QUERY_STRING", args, 1);
-        printf("QUERY_STRING = %s\n", args);
-        /* legacy compatibility */
-        setenv("SELECTOR", args, 1);
-        printf("SELECTOR = %s\n", args);
-        setenv("REQUEST", args, 1);
-        printf("REQUEST = %s\n", args);
+        setenv("SELECTOR", sel, 1);
+        setenv("REQUEST", sel, 1);
+        setenv("TRAVERSAL", traverse, 1);
 
         setenv("REMOTE_ADDR", chost, 1);
-        printf("REMOTE_ADDR = %s\n", chost);
         /*
          * Don't do a reverse lookup on every call. Only do when needed, in
          * the script. The RFC allows us to set the IP to the value.
          */
         setenv("REMOTE_HOST", chost, 1);
-        printf("REMOTE_HOST = %s\n", chost);
         /* Please do not implement identd here. */
         unsetenv("REMOTE_IDENT");
         unsetenv("REMOTE_USER");
@@ -578,12 +572,9 @@ setcgienviron(char *file, char *path, char *port, char *base, char *args,
          */
         setenv("REQUEST_METHOD", "GET", 1);
         setenv("SCRIPT_NAME", file, 1);
-        printf("SCRIPT_NAME = %s\n", file);
         setenv("SERVER_NAME", ohost, 1);
-        printf("SERVER_PORT = %s\n", port);
         setenv("SERVER_PORT", port, 1);
         setenv("SERVER_LISTEN_NAME", bhost, 1);
-        printf("SERVER_LISTEN_NAME = %s\n", bhost);
         if (istls) {
                 setenv("SERVER_PROTOCOL", "gophers/1.0", 1);
         } else {
@@ -592,10 +583,8 @@ setcgienviron(char *file, char *path, char *port, char *base, char *args,
         setenv("SERVER_SOFTWARE", "geomyidae", 1);
 
         setenv("X_GOPHER_SEARCH", sear, 1);
-        printf("X_GOPHER_SEARCH = %s\n", sear);
         /* legacy compatibility */
         setenv("SEARCHREQUEST", sear, 1);
-        printf("SEARCHREQUEST = %s\n", sear);
 
         if (istls) {
                 setenv("GOPHERS", "on", 1);

diff --git a/ind.h b/ind.h

@@ -15,7 +15,7 @@ struct filetype {
         char *end;
         char *type;
         void (* f)(int, char *, char *, char *, char *, char *, char *,
-                char *, char *, int);
+                char *, char *, int, char *, char *);
 };
 
 filetype *gettype(char *filename);
@@ -51,7 +51,7 @@ char *smprintf(char *fmt, ...);
 char *reverselookup(char *host);
 void setcgienviron(char *file, char *path, char *port, char *base,
                 char *args, char *sear, char *ohost, char *chost,
-                char *bhost, int istls);
+                char *bhost, int istls, char *sel, char *traverse);
 char *humansize(off_t n);
 char *humantime(const time_t *clock);
 

diff --git a/main.c b/main.c

@@ -137,8 +137,9 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
               char *serverp, int nocgi, int istls)
 {
         struct stat dir;
-        char recvc[1025], recvb[1025], path[1025], args[1025], argsc[1025],
-                *sear, *c, *sep, *recvbp;
+        char recvc[1025], recvb[1025], path[PATH_MAX+1], rpath[PATH_MAX+1], args[1025],
+                argsc[1025], traverse[1025], traversec[1025],
+                *sear, *sep, *recvbp, *c;
         int len = 0, fd, i, maxrecv, pathfallthrough = 0;
         filetype *type;
 
@@ -172,6 +173,7 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
         memset(recvc, 0, sizeof(recvc));
         memset(args, 0, sizeof(args));
         memset(argsc, 0, sizeof(argsc));
+        memset(traverse, 0, sizeof(argsc));
 
         maxrecv = sizeof(recvb) - 1;
         if (rlen > maxrecv || rlen < 0)
@@ -241,18 +243,19 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
         c = strchr(recvb, '?');
         if (c != NULL) {
                 *c++ = '\0';
-                snprintf(args, sizeof(args), "?%s", c);
+                snprintf(args, sizeof(args), "%s", c);
         }
         printf("args = %s\n", args);
         printf("recvb = %s\n", recvb);
 
         /* Strip '/' at the end of the request. */
         for (c = recvb + strlen(recvb) - 1; c >= recvb && c[0] == '/'; c--) {
-                /* Prepend to args. */
-                snprintf(args, sizeof(args), "/%s", args);
+                memmove(traversec, traverse, strlen(traverse));
+                /* Prepend to traverse. */
+                snprintf(traverse, sizeof(traverse), "/%s", traversec);
                 c[0] = '\0';
         }
-        printf("args = %s\n", args);
+        printf("traverse = %s\n", traverse);
 
         /* Do not allow requests including "..". */
         if (strstr(recvb, "..")) {
@@ -284,8 +287,7 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
          *        $args = $rest_of_path + "?" + $args
          */
         if (stat(path, &dir) == -1) {
-                printf("Not found. Try backtraversal.\n");
-                memmove(argsc, args, strlen(args));
+                memmove(traversec, traverse, strlen(traverse));
                 snprintf(path, sizeof(path), "%s", base);
                 recvbp = recvb;
 
@@ -295,44 +297,42 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
                  * etc.
                  */
                 while (recvbp != NULL) {
-                        /* Traverse multiple / in selector. */
-                        for (sep = recvbp; sep != recvbp && sep != recvbp+1;
-                                sep = strsep(&recvbp, "/"));
-                        printf("traversal directory = %s\n", sep);
+                        /* Traverse multiple empty / in selector. */
+                        while(recvbp[0] == '/')
+                                recvbp++;
+                        sep = strchr(recvbp, '/');
+                        if (sep != NULL)
+                                *sep++ = '\0';
 
-                        /* Append found directory to path. */
                         snprintf(path+strlen(path), sizeof(path)-strlen(path),
-                                "/%s", sep);
+                                "/%s", recvbp);
                         /* path is now always at least '/' */
-                        printf("full traversal path = %s\n", path);
-
                         if (stat(path, &dir) == -1) {
-                                /*
-                                 * Current try was not found. Go back one
-                                 * step and finish.
-                                 */
-                                c = strrchr(path, '/');
-                                if (c != NULL) {
-                                        *c++ = '\0';
-                                        snprintf(args, sizeof(args),
-                                                "/%s%s%s%s",
-                                                c,
-                                                (recvbp != NULL)? "/" : "",
-                                                (recvbp != NULL)? recvbp : "",
-                                                (argsc[0] != '\0')? argsc : ""
-                                        );
-                                        printf("args = %s\n", args);
-                                }
+                                path[strlen(path)-strlen(recvbp)-1] = '\0';
+                                snprintf(traverse, sizeof(traverse),
+                                        "/%s%s%s%s",
+                                        recvbp,
+                                        (sep != NULL)? "/" : "",
+                                        (sep != NULL)? sep : "",
+                                        (traversec[0] != '\0')? traversec : ""
+                                );
                                 /* path fallthrough */
                                 pathfallthrough = 1;
                                 printf("pathfallthrough = 1\n");
                                 break;
                         }
+                        /* Append found directory to path. */
+                        recvbp = sep;
                 }
         }
 
-        printf("path = %s\n", path);
-        if (stat(path, &dir) != -1) {
+        if (realpath(path, (char *)&rpath) == NULL) {
+                dprintf(sock, notfounderr, recvc);
+                if (loglvl & ERRORS)
+                        logentry(clienth, clientp, recvc, "not found");
+        }
+        printf("rpath = %s\n", rpath);
+        if (stat(rpath, &dir) != -1) {
                 /*
                  * If sticky bit is set, only serve if this is encrypted.
                  */
@@ -349,9 +349,9 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
                         printf("S_ISDIR\n");
                         for (i = 0; i < sizeof(indexf)/sizeof(indexf[0]);
                                         i++) {
-                                len = strlen(path);
-                                if (len + strlen(indexf[i]) + (path[len-1] == '/')? 0 : 1
-                                                >= sizeof(path)) {
+                                len = strlen(rpath);
+                                if (len + strlen(indexf[i]) + (rpath[len-1] == '/')? 0 : 1
+                                                >= sizeof(rpath)) {
                                         if (loglvl & ERRORS) {
                                                 logentry(clienth, clientp,
                                                         recvc,
@@ -359,21 +359,19 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
                                         }
                                         return;
                                 }
-                                sprintf(path, "%s%s%s",
-                                        path,
-                                        (path[len-1] == '/')? "" : "/",
-                                        indexf[i]);
-                                printf("path index = %s\n", path);
-                                fd = open(path, O_RDONLY);
+                                if (rpath[len-1] != '/')
+                                        strcat(rpath, "/");
+                                strcat(rpath, indexf[i]);
+                                printf("path index = %s\n", rpath);
+                                fd = open(rpath, O_RDONLY);
                                 if (fd >= 0)
                                         break;
 
                                 /* Not found. Clear path from indexf. */
-                                printf("len = %d\n", len);
-                                path[len] = '\0';
+                                rpath[len] = '\0';
                         }
                 } else {
-                        fd = open(path, O_RDONLY);
+                        fd = open(rpath, O_RDONLY);
                         if (fd < 0) {
                                 dprintf(sock, notfounderr, recvc);
                                 if (loglvl & ERRORS) {
@@ -389,9 +387,9 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
         if (fd >= 0) {
                 close(fd);
 
-                c = strrchr(path, '/');
+                c = strrchr(rpath, '/');
                 if (c == NULL)
-                        c = path;
+                        c = rpath;
                 type = gettype(c);
 
                 /*
@@ -416,8 +414,8 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
                         if (loglvl & FILES)
                                 logentry(clienth, clientp, recvc, "serving");
 
-                        type->f(sock, path, port, base, args, sear, ohost,
-                                clienth, serverh, istls);
+                        type->f(sock, rpath, port, base, args, sear, ohost,
+                                clienth, serverh, istls, recvc, traverse);
                 }
         } else {
                 if (pathfallthrough && S_ISDIR(dir.st_mode)) {
@@ -429,8 +427,8 @@ handlerequest(int sock, char *req, int rlen, char *base, char *ohost,
                 }
 
                 if (!pathfallthrough && S_ISDIR(dir.st_mode)) {
-                        handledir(sock, path, port, base, args, sear, ohost,
-                                clienth, serverh, istls);
+                        handledir(sock, rpath, port, base, args, sear, ohost,
+                                clienth, serverh, istls, recvc, traverse);
                         if (loglvl & DIRS) {
                                 logentry(clienth, clientp, recvc,
                                                         "dir listing");