Separate vger functions into a new file

This will ease the creation of unit tests
and code reusability
master
Solene Rapenne 1 month ago
parent 8bd1144178
commit 9cca2408c3
  1. 2
      Makefile
  2. 318
      main.c
  3. 297
      vger.c
  4. 27
      vger.h

@ -17,7 +17,7 @@ clean:
-name "*.core" \) \
-delete
vger: main.o mimes.o utils.o opts.h
vger: vger.o main.o mimes.o utils.o opts.h
${CC} ${CFLAGS} -o $@ main.o mimes.o utils.o
install: vger

318
main.c

@ -1,320 +1,4 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "mimes.h"
#include "opts.h"
#include "utils.h"
/* length of "gemini://" */
#define GEMINI_PART 9
/*
* number of bytes to read with fgets() : 2014 + 1.
* fgets() reads at most size-1 (1024 here).
* See https://gemini.circumlunar.space/docs/specification.html.
*/
#define GEMINI_REQUEST_MAX 1025
void autoindex(const char *);
void cgi (const char *cgicmd);
void display_file(const char *);
void drop_privileges(const char *, const char *);
void echdir (const char *);
void status (const int, const char *);
void status_redirect(const int, const char *);
void status_error(const int, const char *);
void strip_trailing_slash(char *path);
int uridecode (char *);
void
echdir(const char *path)
{
if (chdir(path) == -1) {
switch (errno) {
case ENOTDIR: /* FALLTHROUGH */
case ENOENT:
status_error(51, "file not found");
break;
case EACCES:
status_error(50, "Forbidden path");
break;
default:
status_error(50, "Internal server error");
break;
}
errlog("failed to chdir(%s)", path);
}
}
int
uridecode(char *uri)
{
int n = 0;
char c = '\0';
long l = 0;
char *pos = NULL;
if ((pos = strchr(uri, '%')) == NULL)
return n;
while ((pos = strchr(pos, '%')) != NULL) {
if (strlen(pos) < 3)
return n;
char hex[3] = {'\0'};
for (size_t i = 0; i < 2; i++)
hex[i] = tolower(pos[i + 1]);
errno = 0;
l = strtol(hex, 0, 16);
if (errno == ERANGE && (l == LONG_MAX || l == LONG_MIN))
continue; /* conversion failed */
c = (char)l;
pos[0] = c;
/* rewind of two char to remove %hex */
memmove(pos + 1, pos + 3, strlen(pos + 3) + 1); /* +1 for \0 */
n++;
pos++; /* avoid infinite loop */
}
return n;
}
void
drop_privileges(const char *user, const char *path)
{
struct passwd *pw;
/*
* use chroot() if an user is specified requires root user to be
* running the program to run chroot() and then drop privileges
*/
if (strlen(user) > 0) {
/* is root? */
if (getuid() != 0)
errlog("chroot requires program to be run as root");
/* search user uid from name */
if ((pw = getpwnam(user)) == NULL)
errlog("the user %s can't be found on the system", user);
/* chroot worked? */
if (chroot(path) != 0)
errlog("the chroot_dir %s can't be used for chroot", path);
chrooted = 1;
echdir("/");
/* drop privileges */
if (setgroups(1, &pw->pw_gid) ||
setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) {
errlog("dropping privileges to user %s (uid=%i) failed",
user, pw->pw_uid);
}
}
#ifdef __OpenBSD__
/*
* prevent access to files other than the one in path
*/
if (chrooted)
eunveil("/", "r");
else
eunveil(path, "r");
/* permission to execute what's inside cgidir */
if (strlen(cgidir) > 0)
eunveil(cgidir, "rx");
eunveil(NULL, NULL); /* no more call to unveil() */
/* promise permissions */
if (strlen(cgidir) > 0)
epledge("stdio rpath exec", NULL);
else
epledge("stdio rpath", NULL);
#endif
if (!chrooted)
echdir(path); /* move to the gemini data directory */
}
void
status(const int code, const char *file_mime)
{
if (strcmp(file_mime, "text/gemini") == 0)
printf("%i %s; %s\r\n", code, file_mime, lang);
else
printf("%i %s\r\n", code, file_mime);
}
void
status_redirect(const int code, const char *url)
{
printf("%i %s\r\n",
code, url);
}
void
status_error(const int code, const char *reason)
{
printf("%i %s\r\n",
code, reason);
}
void
display_file(const char *fname)
{
FILE *fd = NULL;
struct stat sb = {0};
ssize_t nread = 0;
const char *file_mime;
char *buffer[BUFSIZ];
char target[FILENAME_MAX] = {'\0'};
char tmp[PATH_MAX] = {'\0'}; /* used to build
* temporary path */
/*
* special case : fname empty. The user requested just the directory
* name
*/
if (strlen(fname) == 0) {
if (stat("index.gmi", &sb) == 0) {
/* there is index.gmi in the current directory */
display_file("index.gmi");
return;
} else if (doautoidx) {
/* no index.gmi, so display autoindex if enabled */
autoindex(".");
return;
} else {
goto err;
}
}
/* this is to check if path exists and obtain metadata later */
if (stat(fname, &sb) == -1) {
/*
* check if fname is a symbolic link if so, redirect using
* its target
*/
if (lstat(fname, &sb) != -1 && S_ISLNK(sb.st_mode) == 1)
goto redirect;
else
goto err;
}
/* check if directory */
if (S_ISDIR(sb.st_mode) != 0) {
/* no ending "/", redirect to "fname/" */
estrlcpy(tmp, fname, sizeof(tmp));
estrlcat(tmp, "/", sizeof(tmp));
status_redirect(31, tmp);
return;
}
/* open the file requested */
if ((fd = fopen(fname, "r")) == NULL)
goto err;
file_mime = get_file_mime(fname, default_mime);
status(20, file_mime);
/* read the file byte after byte in buffer and write it to stdout */
while ((nread = fread(buffer, 1, sizeof(buffer), fd)) != 0)
fwrite(buffer, 1, nread, stdout);
goto closefd; /* close file descriptor */
syslog(LOG_DAEMON, "path served %s", fname);
return;
err:
/* return an error code and no content */
status_error(51, "file not found");
syslog(LOG_DAEMON, "path invalid %s", fname);
goto closefd;
redirect:
/* read symbolic link target to redirect */
if (readlink(fname, target, FILENAME_MAX) == -1)
goto err;
status_redirect(30, target);
syslog(LOG_DAEMON, "redirection from %s to %s", fname, target);
closefd:
if (S_ISREG(sb.st_mode) != 0)
fclose(fd);
}
void
autoindex(const char *path)
{
/* display liks to files in path + a link to parent (..) */
int n = 0;
struct dirent **namelist; /* this must be freed at last */
syslog(LOG_DAEMON, "autoindex: %s", path);
/* use alphasort to always have the same order on every system */
if ((n = scandir(path, &namelist, NULL, alphasort)) < 0) {
status_error(50, "Internal server error");
errlog("Can't scan %s", path);
} else {
status(20, "text/gemini");
printf("=> .. ../\n"); /* display link to parent */
for (int j = 0; j < n; j++) {
/* skip self and parent */
if ((strcmp(namelist[j]->d_name, ".") == 0) ||
(strcmp(namelist[j]->d_name, "..") == 0)) {
continue;
}
/* add "/" at the end of a directory path */
if (namelist[j]->d_type == DT_DIR)
printf("=> ./%s/ %s/\n", namelist[j]->d_name, namelist[j]->d_name);
else
printf("=> ./%s %s\n", namelist[j]->d_name, namelist[j]->d_name);
free(namelist[j]);
}
free(namelist);
}
}
void
cgi(const char *cgicmd)
{
/* run cgicmd replacing current process */
execl(cgicmd, cgicmd, NULL);
/* if execl is ok, this will never be reached */
status(42, "Couldn't execute CGI script");
errlog("error when trying to execl %s", cgicmd);
exit(1);
}
void
strip_trailing_slash(char *path)
{
size_t end = strlen(path);
if (end == 0)
return;
end--;
while (path[end] == '/')
path[end--] = '\0';
}
#include "vger.c"
int
main(int argc, char **argv)

297
vger.c

@ -0,0 +1,297 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "mimes.h"
#include "opts.h"
#include "utils.h"
#include "vger.h"
void
echdir(const char *path)
{
if (chdir(path) == -1) {
switch (errno) {
case ENOTDIR: /* FALLTHROUGH */
case ENOENT:
status_error(51, "file not found");
break;
case EACCES:
status_error(50, "Forbidden path");
break;
default:
status_error(50, "Internal server error");
break;
}
errlog("failed to chdir(%s)", path);
}
}
int
uridecode(char *uri)
{
int n = 0;
char c = '\0';
long l = 0;
char *pos = NULL;
if ((pos = strchr(uri, '%')) == NULL)
return n;
while ((pos = strchr(pos, '%')) != NULL) {
if (strlen(pos) < 3)
return n;
char hex[3] = {'\0'};
for (size_t i = 0; i < 2; i++)
hex[i] = tolower(pos[i + 1]);
errno = 0;
l = strtol(hex, 0, 16);
if (errno == ERANGE && (l == LONG_MAX || l == LONG_MIN))
continue; /* conversion failed */
c = (char)l;
pos[0] = c;
/* rewind of two char to remove %hex */
memmove(pos + 1, pos + 3, strlen(pos + 3) + 1); /* +1 for \0 */
n++;
pos++; /* avoid infinite loop */
}
return n;
}
void
drop_privileges(const char *user, const char *path)
{
struct passwd *pw;
/*
* use chroot() if an user is specified requires root user to be
* running the program to run chroot() and then drop privileges
*/
if (strlen(user) > 0) {
/* is root? */
if (getuid() != 0)
errlog("chroot requires program to be run as root");
/* search user uid from name */
if ((pw = getpwnam(user)) == NULL)
errlog("the user %s can't be found on the system", user);
/* chroot worked? */
if (chroot(path) != 0)
errlog("the chroot_dir %s can't be used for chroot", path);
chrooted = 1;
echdir("/");
/* drop privileges */
if (setgroups(1, &pw->pw_gid) ||
setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) {
errlog("dropping privileges to user %s (uid=%i) failed",
user, pw->pw_uid);
}
}
#ifdef __OpenBSD__
/*
* prevent access to files other than the one in path
*/
if (chrooted)
eunveil("/", "r");
else
eunveil(path, "r");
/* permission to execute what's inside cgidir */
if (strlen(cgidir) > 0)
eunveil(cgidir, "rx");
eunveil(NULL, NULL); /* no more call to unveil() */
/* promise permissions */
if (strlen(cgidir) > 0)
epledge("stdio rpath exec", NULL);
else
epledge("stdio rpath", NULL);
#endif
if (!chrooted)
echdir(path); /* move to the gemini data directory */
}
void
status(const int code, const char *file_mime)
{
if (strcmp(file_mime, "text/gemini") == 0)
printf("%i %s; %s\r\n", code, file_mime, lang);
else
printf("%i %s\r\n", code, file_mime);
}
void
status_redirect(const int code, const char *url)
{
printf("%i %s\r\n",
code, url);
}
void
status_error(const int code, const char *reason)
{
printf("%i %s\r\n",
code, reason);
}
void
display_file(const char *fname)
{
FILE *fd = NULL;
struct stat sb = {0};
ssize_t nread = 0;
const char *file_mime;
char *buffer[BUFSIZ];
char target[FILENAME_MAX] = {'\0'};
char tmp[PATH_MAX] = {'\0'}; /* used to build
* temporary path */
/*
* special case : fname empty. The user requested just the directory
* name
*/
if (strlen(fname) == 0) {
if (stat("index.gmi", &sb) == 0) {
/* there is index.gmi in the current directory */
display_file("index.gmi");
return;
} else if (doautoidx) {
/* no index.gmi, so display autoindex if enabled */
autoindex(".");
return;
} else {
goto err;
}
}
/* this is to check if path exists and obtain metadata later */
if (stat(fname, &sb) == -1) {
/*
* check if fname is a symbolic link if so, redirect using
* its target
*/
if (lstat(fname, &sb) != -1 && S_ISLNK(sb.st_mode) == 1)
goto redirect;
else
goto err;
}
/* check if directory */
if (S_ISDIR(sb.st_mode) != 0) {
/* no ending "/", redirect to "fname/" */
estrlcpy(tmp, fname, sizeof(tmp));
estrlcat(tmp, "/", sizeof(tmp));
status_redirect(31, tmp);
return;
}
/* open the file requested */
if ((fd = fopen(fname, "r")) == NULL)
goto err;
file_mime = get_file_mime(fname, default_mime);
status(20, file_mime);
/* read the file byte after byte in buffer and write it to stdout */
while ((nread = fread(buffer, 1, sizeof(buffer), fd)) != 0)
fwrite(buffer, 1, nread, stdout);
goto closefd; /* close file descriptor */
syslog(LOG_DAEMON, "path served %s", fname);
return;
err:
/* return an error code and no content */
status_error(51, "file not found");
syslog(LOG_DAEMON, "path invalid %s", fname);
goto closefd;
redirect:
/* read symbolic link target to redirect */
if (readlink(fname, target, FILENAME_MAX) == -1)
goto err;
status_redirect(30, target);
syslog(LOG_DAEMON, "redirection from %s to %s", fname, target);
closefd:
if (S_ISREG(sb.st_mode) != 0)
fclose(fd);
}
void
autoindex(const char *path)
{
/* display liks to files in path + a link to parent (..) */
int n = 0;
struct dirent **namelist; /* this must be freed at last */
syslog(LOG_DAEMON, "autoindex: %s", path);
/* use alphasort to always have the same order on every system */
if ((n = scandir(path, &namelist, NULL, alphasort)) < 0) {
status_error(50, "Internal server error");
errlog("Can't scan %s", path);
} else {
status(20, "text/gemini");
printf("=> .. ../\n"); /* display link to parent */
for (int j = 0; j < n; j++) {
/* skip self and parent */
if ((strcmp(namelist[j]->d_name, ".") == 0) ||
(strcmp(namelist[j]->d_name, "..") == 0)) {
continue;
}
/* add "/" at the end of a directory path */
if (namelist[j]->d_type == DT_DIR)
printf("=> ./%s/ %s/\n", namelist[j]->d_name, namelist[j]->d_name);
else
printf("=> ./%s %s\n", namelist[j]->d_name, namelist[j]->d_name);
free(namelist[j]);
}
free(namelist);
}
}
void
cgi(const char *cgicmd)
{
/* run cgicmd replacing current process */
execl(cgicmd, cgicmd, NULL);
/* if execl is ok, this will never be reached */
status(42, "Couldn't execute CGI script");
errlog("error when trying to execl %s", cgicmd);
exit(1);
}
void
strip_trailing_slash(char *path)
{
size_t end = strlen(path);
if (end == 0)
return;
end--;
while (path[end] == '/')
path[end--] = '\0';
}

@ -0,0 +1,27 @@
#ifndef vger_h_INCLUDED
#define vger_h_INCLUDED
/* length of "gemini://" */
#define GEMINI_PART 9
/*
* number of bytes to read with fgets() : 2014 + 1.
* fgets() reads at most size-1 (1024 here).
* See https://gemini.circumlunar.space/docs/specification.html.
*/
#define GEMINI_REQUEST_MAX 1025
void autoindex(const char *);
void cgi (const char *cgicmd);
void display_file(const char *);
void drop_privileges(const char *, const char *);
void echdir (const char *);
void status (const int, const char *);
void status_redirect(const int, const char *);
void status_error(const int, const char *);
void strip_trailing_slash(char *path);
int uridecode (char *);
#endif // vger_h_INCLUDED
Loading…
Cancel
Save