From 0cd9d59dfadf1a9abbef4428ff4f90bf32c01bd4 Mon Sep 17 00:00:00 2001 Message-Id: <0cd9d59dfadf1a9abbef4428ff4f90bf32c01bd4.1746338000.git.mdw@distorted.org.uk> From: Mark Wooding Date: Mon, 28 Mar 2016 23:27:56 +0100 Subject: [PATCH] ucgi/: Return useful status codes when things go wrong. Organization: Straylight/Edgeware From: Mark Wooding It's simply wrong for the ucgi machinery to report status 200 OK when it encounters trouble (e.g., the CGI program doesn't actually exist). So report a useful status code as part of `error' or `syserror'. We assume that the latter is always a server-side error; the former might be either, so we must annotate each call as appropriate. --- www-cgi/ucgi.c | 20 ++++++++++++-------- www-cgi/ucgi.h | 2 +- www-cgi/ucgicommon.c | 16 +++++++++------- www-cgi/ucgitarget.c | 28 +++++++++++++++------------- 4 files changed, 37 insertions(+), 29 deletions(-) diff --git a/www-cgi/ucgi.c b/www-cgi/ucgi.c index 980bec5..845eb44 100644 --- a/www-cgi/ucgi.c +++ b/www-cgi/ucgi.c @@ -57,7 +57,7 @@ struct buildargs { }; static void addarg(struct buildargs *args, const char *a) { - if (args->n > args->max) error("too many arguments"); + if (args->n > args->max) error("too many arguments", 500); args->v[args->n++]= a; } @@ -67,7 +67,8 @@ static void add_userv_var(const char *fulln, size_t l; char *a; - l= strlen(ev); if (l > MAX_ENVVAR_VALUE) error("environment variable too long"); + l= strlen(ev); + if (l > MAX_ENVVAR_VALUE) error("environment variable too long", 500); a= xmalloc(strlen(en)+l+6); sprintf(a,"-DE_%s=%s",en,ev); addarg(args, a); @@ -92,7 +93,7 @@ int main(int argc, const char **argv) { D( printf(";;; UCGI\n"); ) } - if (argc > MAX_ARGS) error("too many arguments"); + if (argc > MAX_ARGS) error("too many arguments", 500); ev= getenv("UCGI_ENV_FILTER"); if (ev) @@ -101,21 +102,24 @@ int main(int argc, const char **argv) { envok= load_filters(0, "/etc/userv/ucgi.env-filter", LF_END); pathi= getenv("PATH_INFO"); - if (!pathi) error("PATH_INFO not found"); + if (!pathi) error("PATH_INFO not found", 500); D( if (debugmode) { printf(";; find user name...\n" ";; initial PATH_INFO = `%s'\n", pathi); } ) - if (pathi[0] != '/' || pathi[1] != '~') error("PATH_INFO must start with /~"); - slash2= strchr(pathi+2,'/'); if (!slash2) error("PATH_INFO must have more than one /"); + if (pathi[0] != '/' || pathi[1] != '~') + error("PATH_INFO must start with /~", 400); + slash2= strchr(pathi+2,'/'); + if (!slash2) error("PATH_INFO must have more than one /", 400); usernamelen= slash2-(pathi+2); - if (usernamelen > MAX_USERNAME_LEN) error("PATH_INFO username too long"); + if (usernamelen > MAX_USERNAME_LEN) error("PATH_INFO username too long", 400); username= xmalloc(usernamelen+1); memcpy(username,pathi+2,usernamelen); username[usernamelen]= 0; D( if (debugmode) printf(";; user = `%s'; tail = `%s'\n", username, slash2); ) - if (!isalpha(username[0])) error("username 1st character is not alphabetic"); + if (!isalpha(username[0])) + error("username 1st character is not alphabetic", 400); xsetenv("PATH_INFO",slash2,1); args.n= 0; args.max= argc + MAX_ENVVARS + 10; diff --git a/www-cgi/ucgi.h b/www-cgi/ucgi.h index 9fbf70c..d4c84bf 100644 --- a/www-cgi/ucgi.h +++ b/www-cgi/ucgi.h @@ -37,7 +37,7 @@ #define MAX_ENVVARS 256 void syserror(const char *m); -void error(const char *m); +void error(const char *m, int st); void *xmalloc(size_t sz); void xsetenv(const char *en, const char *ev, int overwrite); void *xrealloc(void *ptr, size_t sz); diff --git a/www-cgi/ucgicommon.c b/www-cgi/ucgicommon.c index 73565b5..2fa6260 100644 --- a/www-cgi/ucgicommon.c +++ b/www-cgi/ucgicommon.c @@ -37,18 +37,20 @@ static void outerror(void) { } void syserror(const char *m) { - if (printf("Content-Type: text/plain\n\n" + if (printf("Content-Type: text/plain\n" + "Status: 500\n\n" "ucgi: system call error:\n" "%s: %s\n", m,strerror(errno))==EOF || fflush(stdout)) outerror(); exit(0); } -void error(const char *m) { - if (printf("Content-Type: text/plain\n\n" +void error(const char *m, int st) { + if (printf("Content-Type: text/plain\n" + "Status: %d\n\n" "ucgi: error:\n" "%s\n", - m)==EOF || fflush(stdout)) outerror(); + st, m)==EOF || fflush(stdout)) outerror(); exit(0); } @@ -104,7 +106,7 @@ opened: l= strlen(buf); if (buf[l - 1] == '\n') buf[--l]= 0; if (l + 1 == sizeof(buf)) - error("line too long in environment filter file"); + error("line too long in environment filter file", 500); p= buf; q= p + l; while (isspace((unsigned char)*p)) p++; while (q > p && isspace((unsigned char)q[-1])) q--; @@ -146,7 +148,7 @@ static int envvar_match(unsigned flags, const char *en, rc= envvar_match(flags, en, defaults, 0, ev); if (rc) return rc; } else - error("unknown pattern directive"); + error("unknown pattern directive", 500); continue; } @@ -208,7 +210,7 @@ void filter_environment(unsigned flags, const char *prefix_in, if (envvar_match(flags, en + pn, patv, defaults, &ev) > 0) { n= strcspn(en, "="); if (n >= sizeof(enbuf)) - error("environment variable name too long"); + error("environment variable name too long", 500); memcpy(enbuf, en, n); enbuf[n]= 0; D( if (debugmode) diff --git a/www-cgi/ucgitarget.c b/www-cgi/ucgitarget.c index 2b6a222..866a2d5 100644 --- a/www-cgi/ucgitarget.c +++ b/www-cgi/ucgitarget.c @@ -109,19 +109,19 @@ int main(int argc, char **argv) { if (ev && *ev) debugmode= 1; D( if (debugmode) printf(";;; UCGITARGET\n"); ) - if (argc > MAX_ARGS) error("too many arguments"); + if (argc > MAX_ARGS) error("too many arguments", 500); for (;;) { i= getopt(argc, argv, "+e:"); if (i < 0) break; switch (i) { case 'e': filters= optarg; break; - default: error("bad command line"); break; + default: error("bad command line", 500); break; } } argc -= optind; argv += optind; - if (!*argv) error("no script directory argument"); - ev= getenv("HOME"); if (!ev) error("no HOME env. var"); + if (!*argv) error("no script directory argument", 500); + ev= getenv("HOME"); if (!ev) error("no HOME env. var", 500); l= strlen(*argv)+strlen(ev); newvar= xmalloc(l+2); sprintf(newvar,"%s/%s",ev,*argv); @@ -141,7 +141,7 @@ int main(int argc, char **argv) { scriptpath= 0; pathi= getenv("PATH_INFO"); - if (!pathi) error("PATH_INFO not found"); + if (!pathi) error("PATH_INFO not found", 500); lastslash= pathi; D( if (debugmode) { printf(";; find script name...\n" @@ -149,23 +149,25 @@ int main(int argc, char **argv) { pathi); } ) for (;;) { - if (*lastslash != '/') error("PATH_INFO expected slash not found"); - if (lastslash[1]=='.' || lastslash[1]=='#' || !lastslash[1]) error("bad char begin"); + if (*lastslash != '/') error("PATH_INFO expected slash not found", 400); + if (lastslash[1]=='.' || lastslash[1]=='#' || !lastslash[1]) + error("bad char begin", 400); nextslash= strchr(lastslash+1,'/'); if (!nextslash) nextslash= lastslash+1+strlen(lastslash+1); - if (!nextslash) error("insufficient elements in PATH_INFO"); - if (nextslash==lastslash+1) error("empty component in PATH_INFO"); - if (nextslash-pathi > MAX_SCRIPTPATH_LEN) error("PATH_INFO script path too long"); + if (!nextslash) error("insufficient elements in PATH_INFO", 400); + if (nextslash==lastslash+1) error("empty component in PATH_INFO", 400); + if (nextslash-pathi > MAX_SCRIPTPATH_LEN) + error("PATH_INFO script path too long", 400); scriptpathlen= scriptdirlen+(nextslash-pathi); scriptpath= xrealloc(scriptpath,scriptpathlen+1); strcpy(scriptpath,scriptdir); memcpy(scriptpath+scriptdirlen,pathi,nextslash-pathi); scriptpath[scriptpathlen]= 0; - if (scriptpath[scriptpathlen-1]=='~') error("bad char end"); + if (scriptpath[scriptpathlen-1]=='~') error("bad char end", 400); D( if (debugmode) printf(";; try `%s'\n", scriptpath); ) r= stat(scriptpath,&stab); if (r) syserror("stat script"); if (S_ISREG(stab.st_mode)) break; - if (!S_ISDIR(stab.st_mode)) error("script not directory or file"); + if (!S_ISDIR(stab.st_mode)) error("script not directory or file", 500); lastslash= nextslash; } D( if (debugmode) printf(";; found script: tail = `%s'\n", nextslash); ) @@ -180,7 +182,7 @@ int main(int argc, char **argv) { ev= getenv("SCRIPT_NAME"); if (ev) { - ev2= getenv("USER"); if (!ev2) error("no USER variable"); + ev2= getenv("USER"); if (!ev2) error("no USER variable", 500); newvar= xmalloc(strlen(ev)+2+strlen(ev2)+scriptpathlen-scriptdirlen+2); sprintf(newvar,"%s/~%s%s",ev,ev2,scriptpath+scriptdirlen); xsetenv("SCRIPT_NAME",newvar,1); -- [mdw]