/* some simple CGI helper routines Copyright (C) Andrew Tridgell 1997 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 2 of the License, 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; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include #include #include #define MAX_VARIABLES 10000 #ifdef DEBUG_COMMENTS extern void print_title(char *fmt, ...); #endif struct var { char *name; char *value; }; static struct var variables[MAX_VARIABLES]; static int num_variables; static int content_length; static int request_post; static int request_get; static char *query_string; static void unescape(char *buf) { char *p=buf; while ((p=strchr(p,'+'))) *p = ' '; p = buf; while (p && *p && (p=strchr(p,'%'))) { int c1 = p[1]; int c2 = p[2]; if (c1 >= '0' && c1 <= '9') c1 = c1 - '0'; else if (c1 >= 'A' && c1 <= 'F') c1 = 10 + c1 - 'A'; else if (c1 >= 'a' && c1 <= 'f') c1 = 10 + c1 - 'a'; else {p++; continue;} if (c2 >= '0' && c2 <= '9') c2 = c2 - '0'; else if (c2 >= 'A' && c2 <= 'F') c2 = 10 + c2 - 'A'; else if (c2 >= 'a' && c2 <= 'f') c2 = 10 + c2 - 'a'; else {p++; continue;} *p = (c1<<4) | c2; memcpy(p+1, p+3, strlen(p+3)+1); p++; } } static char *grab_line(FILE *f, int *cl) { char *ret; int i = 0; int len = 1024; ret = (char *)malloc(len); if (!ret) return NULL; while ((*cl)) { int c = fgetc(f); (*cl)--; if (c == EOF) { (*cl) = 0; break; } if (c == '\r') continue; if (strchr("\n&", c)) break; ret[i++] = c; if (i == len-1) { char *ret2; ret2 = (char *)realloc(ret, len*2); if (!ret2) return ret; len *= 2; ret = ret2; } } ret[i] = 0; return ret; } /*************************************************************************** load all the variables passed to the CGI program. May have multiple variables with the same name and the same or different values. Takes a file parameter for simulating CGI invocation eg loading saved preferences. ***************************************************************************/ void cgi_load_variables(FILE *f1) { FILE *f = f1; static char *line; char *p, *s, *tok; int len; #ifdef DEBUG_COMMENTS char dummy[100]=""; print_title(dummy); printf("\n",__FILE__); #endif if (!f1) { f = stdin; if (!content_length) { p = getenv("CONTENT_LENGTH"); len = p?atoi(p):0; } else { len = content_length; } } else { fseek(f, 0, SEEK_END); len = ftell(f); fseek(f, 0, SEEK_SET); } if (len > 0 && (f1 || request_post || ((s=getenv("REQUEST_METHOD")) && strcasecmp(s,"POST")==0))) { while (len && (line=grab_line(f, &len))) { p = strchr(line,'='); if (!p) continue; *p = 0; variables[num_variables].name = strdup(line); variables[num_variables].value = strdup(p+1); free(line); if (!variables[num_variables].name || !variables[num_variables].value) continue; unescape(variables[num_variables].value); unescape(variables[num_variables].name); #ifdef DEBUG_COMMENTS printf("\n", variables[num_variables].name, variables[num_variables].value); #endif num_variables++; if (num_variables == MAX_VARIABLES) break; } } if (f1) { #ifdef DEBUG_COMMENTS printf("\n"); #endif return; } fclose(stdin); if ((s=query_string) || (s=getenv("QUERY_STRING"))) { for (tok=strtok(s,"&;");tok;tok=strtok(NULL,"&;")) { p = strchr(tok,'='); if (!p) continue; *p = 0; variables[num_variables].name = strdup(tok); variables[num_variables].value = strdup(p+1); if (!variables[num_variables].name || !variables[num_variables].value) continue; unescape(variables[num_variables].value); unescape(variables[num_variables].name); #ifdef DEBUG_COMMENTS printf("\n", variables[num_variables].name, variables[num_variables].value); #endif num_variables++; if (num_variables == MAX_VARIABLES) break; } } #ifdef DEBUG_COMMENTS printf("\n"); #endif } /*************************************************************************** find a variable passed via CGI Doesn't quite do what you think in the case of POST text variables, because if they exist they might have a value of "" or even " ", depending on the browser. Also doesn't allow for variables[] containing multiple variables with the same name and the same or different values. ***************************************************************************/ char *cgi_variable(char *name) { int i; for (i=0;i= num_variables) return NULL; *name = variables[i].name; return variables[i].value; } /*************************************************************************** return the value of a CGI boolean variable. ***************************************************************************/ int cgi_boolean(char *name, int def) { char *p = cgi_variable(name); if (!p) return def; return strcmp(p, "1") == 0; } /*************************************************************************** like strdup() but quotes < > and & ***************************************************************************/ char *quotedup(char *s) { int i, n=0; int len; char *ret; char *d; if (!s) return strdup(""); len = strlen(s); for (i=0;i' || s[i] == '&') n++; ret = malloc(len + n*6 + 1); if (!ret) return NULL; d = ret; for (i=0;i': strcpy(d, ">"); d += 4; break; case '&': strcpy(d, "&"); d += 5; break; default: *d++ = s[i]; } } *d = 0; return ret; } /*************************************************************************** like strdup() but quotes a wide range of characters ***************************************************************************/ char *urlquote(char *s) { int i, n=0; int len; char *ret; char *d; char *qlist = "\"\n\r'&<> \t+;"; if (!s) return strdup(""); len = strlen(s); for (i=0;i%s

%s

%s

\r\n", err, header, err, err, info); exit(0); } /*************************************************************************** decode a base64 string in-place - simple and slow algorithm ***************************************************************************/ static void base64_decode(char *s) { char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; int bit_offset, byte_offset, idx, i; unsigned char *d = (unsigned char *)s; char *p; i=0; while (*s && (p=strchr(b64,*s))) { idx = (int)(p - b64); byte_offset = (i*6)/8; bit_offset = (i*6)%8; d[byte_offset] &= ~((1<<(8-bit_offset))-1); if (bit_offset < 3) { d[byte_offset] |= (idx << (2-bit_offset)); } else { d[byte_offset] |= (idx >> (bit_offset-2)); d[byte_offset+1] = 0; d[byte_offset+1] |= (idx << (8-(bit_offset-2))) & 0xFF; } s++; i++; } } /*************************************************************************** handle a http authentication line ***************************************************************************/ static int cgi_handle_authorization(char *line) { char *p, *user, *pass; struct passwd *pwd; int ret=0; if (strncasecmp(line,"Basic ", 6)) { cgi_setup_error("401 Bad Authorization", "", "Only basic authorization is understood"); } line += 6; while (line[0] == ' ') line++; base64_decode(line); if (!(p=strchr(line,':'))) { cgi_setup_error("401 Bad Authorization", "", "username/password must be supplied"); } *p = 0; user = line; pass = p+1; /* currently only allow connections as root */ if (strcasecmp(user,"root")) { cgi_setup_error("401 Bad Authorization", "", "incorrect username/password"); } pwd = getpwnam(user); if (!strcmp((char *)crypt(pass, pwd->pw_passwd),pwd->pw_passwd)) { ret = 1; } memset(pass, 0, strlen(pass)); return ret; } /*************************************************************************** handle a file download ***************************************************************************/ static void cgi_download(char *file) { struct stat st; char buf[1024]; int fd, l, i; char *p; /* sanitise the filename */ for (i=0;file[i];i++) { if (!isalnum(file[i]) && !strchr("/.-_", file[i])) { cgi_setup_error("404 File Not Found","", "Illegal character in filename"); } } if (strstr(file,"..")) { cgi_setup_error("404 File Not Found","", "Relative paths not allowed"); } if (!file_exist(file, &st)) { cgi_setup_error("404 File Not Found","", "The requested file was not found"); } fd = open(file,O_RDONLY); if (fd == -1) { cgi_setup_error("404 File Not Found","", "The requested file was not found"); } printf("HTTP/1.1 200 OK\r\n"); if ((p=strrchr(file,'.'))) { if (strcmp(p,".gif")==0 || strcmp(p,".jpg")==0) { printf("Content-Type: image/gif\r\n"); } else { printf("Content-Type: text/html\r\n"); } } printf("Content-Length: %d\r\n\r\n", (int)st.st_size); while ((l=read(fd,buf,sizeof(buf)))>0) { fwrite(buf, 1, l, stdout); } close(fd); exit(0); } /*************************************************************************** setup the cgi framework, handling the possability that this program is either run as a true cgi program by a web browser or is itself a mini web server ***************************************************************************/ void cgi_setup(char *rootdir) { int authenticated = 0; char line[1024]; char *url=NULL; char *p; if (chdir(rootdir)) { cgi_setup_error("400 Server Error", "", "chdir failed - the server is not configured correctly"); } if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) { /* assume we are running under a real web server */ return; } /* we are a mini-web server. We need to read the request from stdin and handle authentication etc */ while (fgets(line, sizeof(line)-1, stdin)) { if (line[0] == '\r' || line[0] == '\n') break; if (strncasecmp(line,"GET ", 4)==0) { request_get = 1; url = strdup(&line[4]); } else if (strncasecmp(line,"POST ", 5)==0) { request_post = 1; url = strdup(&line[5]); } else if (strncasecmp(line,"PUT ", 4)==0) { cgi_setup_error("400 Bad Request", "", "This server does not accept PUT requests"); } else if (strncasecmp(line,"Authorization: ", 15)==0) { authenticated = cgi_handle_authorization(&line[15]); } else if (strncasecmp(line,"Content-Length: ", 16)==0) { content_length = atoi(&line[16]); } /* ignore all other requests! */ } if (!authenticated) { cgi_setup_error("401 Authorization Required", "WWW-Authenticate: Basic realm=\"root\"\r\n", "You must be authenticated to use this service"); } if (!url) { cgi_setup_error("400 Bad Request", "", "You must specify a GET or POST request"); } /* trim the URL */ if ((p = strchr(url,' ')) || (p=strchr(url,'\t'))) { *p = 0; } while (*url && strchr("\r\n",url[strlen(url)-1])) { url[strlen(url)-1] = 0; } /* anything following a ? in the URL is part of the query string */ if ((p=strchr(url,'?'))) { query_string = p+1; *p = 0; } if (strcmp(url,"/")) { cgi_download(url+1); } printf("HTTP/1.1 200 OK\r\nConnection: close\r\nContent-Type: text/html\r\n\r\n"); }