This will ease the creation of unit tests and code reusabilitymaster
Solene Rapenne
1 month ago
parent
8bd1144178
commit
9cca2408c3
4 changed files with 326 additions and 318 deletions
@ -0,0 +1,297 @@ |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <sys/wait.h> |
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#include <ctype.h> |
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#include <dirent.h> |
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#include <err.h> |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <limits.h> |
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#include <pwd.h> |
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#include <stdarg.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <syslog.h> |
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#include <unistd.h> |
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#include "mimes.h" |
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#include "opts.h" |
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#include "utils.h" |
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#include "vger.h" |
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void |
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echdir(const char *path) |
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{ |
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if (chdir(path) == -1) { |
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switch (errno) { |
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case ENOTDIR: /* FALLTHROUGH */ |
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case ENOENT: |
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status_error(51, "file not found"); |
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break; |
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case EACCES: |
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status_error(50, "Forbidden path"); |
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break; |
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default: |
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status_error(50, "Internal server error"); |
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break; |
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} |
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errlog("failed to chdir(%s)", path); |
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} |
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} |
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|
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int |
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uridecode(char *uri) |
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{ |
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int n = 0; |
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char c = '\0'; |
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long l = 0; |
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char *pos = NULL; |
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if ((pos = strchr(uri, '%')) == NULL) |
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return n; |
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while ((pos = strchr(pos, '%')) != NULL) { |
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if (strlen(pos) < 3) |
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return n; |
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char hex[3] = {'\0'}; |
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for (size_t i = 0; i < 2; i++) |
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hex[i] = tolower(pos[i + 1]); |
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errno = 0; |
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l = strtol(hex, 0, 16); |
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if (errno == ERANGE && (l == LONG_MAX || l == LONG_MIN)) |
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continue; /* conversion failed */ |
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c = (char)l; |
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pos[0] = c; |
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/* rewind of two char to remove %hex */ |
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memmove(pos + 1, pos + 3, strlen(pos + 3) + 1); /* +1 for \0 */ |
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n++; |
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pos++; /* avoid infinite loop */ |
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} |
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return n; |
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} |
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void |
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drop_privileges(const char *user, const char *path) |
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{ |
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struct passwd *pw; |
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/*
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* use chroot() if an user is specified requires root user to be |
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* running the program to run chroot() and then drop privileges |
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*/ |
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if (strlen(user) > 0) { |
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/* is root? */ |
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if (getuid() != 0) |
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errlog("chroot requires program to be run as root"); |
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/* search user uid from name */ |
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if ((pw = getpwnam(user)) == NULL) |
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errlog("the user %s can't be found on the system", user); |
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/* chroot worked? */ |
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if (chroot(path) != 0) |
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errlog("the chroot_dir %s can't be used for chroot", path); |
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chrooted = 1; |
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echdir("/"); |
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/* drop privileges */ |
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if (setgroups(1, &pw->pw_gid) || |
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setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || |
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setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) { |
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errlog("dropping privileges to user %s (uid=%i) failed", |
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user, pw->pw_uid); |
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} |
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} |
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#ifdef __OpenBSD__ |
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/*
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* prevent access to files other than the one in path |
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*/ |
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if (chrooted) |
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eunveil("/", "r"); |
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else |
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eunveil(path, "r"); |
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/* permission to execute what's inside cgidir */ |
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if (strlen(cgidir) > 0) |
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eunveil(cgidir, "rx"); |
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eunveil(NULL, NULL); /* no more call to unveil() */ |
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/* promise permissions */ |
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if (strlen(cgidir) > 0) |
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epledge("stdio rpath exec", NULL); |
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else |
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epledge("stdio rpath", NULL); |
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#endif |
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if (!chrooted) |
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echdir(path); /* move to the gemini data directory */ |
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} |
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void |
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status(const int code, const char *file_mime) |
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{ |
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if (strcmp(file_mime, "text/gemini") == 0) |
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printf("%i %s; %s\r\n", code, file_mime, lang); |
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else |
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printf("%i %s\r\n", code, file_mime); |
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} |
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void |
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status_redirect(const int code, const char *url) |
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{ |
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printf("%i %s\r\n", |
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code, url); |
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} |
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void |
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status_error(const int code, const char *reason) |
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{ |
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printf("%i %s\r\n", |
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code, reason); |
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} |
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void |
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display_file(const char *fname) |
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{ |
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FILE *fd = NULL; |
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struct stat sb = {0}; |
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ssize_t nread = 0; |
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const char *file_mime; |
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char *buffer[BUFSIZ]; |
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char target[FILENAME_MAX] = {'\0'}; |
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char tmp[PATH_MAX] = {'\0'}; /* used to build
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* temporary path */ |
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/*
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* special case : fname empty. The user requested just the directory |
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* name |
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*/ |
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if (strlen(fname) == 0) { |
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if (stat("index.gmi", &sb) == 0) { |
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/* there is index.gmi in the current directory */ |
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display_file("index.gmi"); |
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return; |
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} else if (doautoidx) { |
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/* no index.gmi, so display autoindex if enabled */ |
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autoindex("."); |
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return; |
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} else { |
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goto err; |
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} |
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} |
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/* this is to check if path exists and obtain metadata later */ |
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if (stat(fname, &sb) == -1) { |
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/*
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* check if fname is a symbolic link if so, redirect using |
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* its target |
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*/ |
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if (lstat(fname, &sb) != -1 && S_ISLNK(sb.st_mode) == 1) |
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goto redirect; |
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else |
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goto err; |
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} |
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/* check if directory */ |
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if (S_ISDIR(sb.st_mode) != 0) { |
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/* no ending "/", redirect to "fname/" */ |
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estrlcpy(tmp, fname, sizeof(tmp)); |
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estrlcat(tmp, "/", sizeof(tmp)); |
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status_redirect(31, tmp); |
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return; |
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} |
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/* open the file requested */ |
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if ((fd = fopen(fname, "r")) == NULL) |
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goto err; |
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file_mime = get_file_mime(fname, default_mime); |
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status(20, file_mime); |
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/* read the file byte after byte in buffer and write it to stdout */ |
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while ((nread = fread(buffer, 1, sizeof(buffer), fd)) != 0) |
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fwrite(buffer, 1, nread, stdout); |
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goto closefd; /* close file descriptor */ |
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syslog(LOG_DAEMON, "path served %s", fname); |
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return; |
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err: |
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/* return an error code and no content */ |
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status_error(51, "file not found"); |
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syslog(LOG_DAEMON, "path invalid %s", fname); |
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goto closefd; |
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redirect: |
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/* read symbolic link target to redirect */ |
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if (readlink(fname, target, FILENAME_MAX) == -1) |
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goto err; |
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status_redirect(30, target); |
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syslog(LOG_DAEMON, "redirection from %s to %s", fname, target); |
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closefd: |
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if (S_ISREG(sb.st_mode) != 0) |
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fclose(fd); |
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} |
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void |
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autoindex(const char *path) |
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{ |
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/* display liks to files in path + a link to parent (..) */ |
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int n = 0; |
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struct dirent **namelist; /* this must be freed at last */ |
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syslog(LOG_DAEMON, "autoindex: %s", path); |
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/* use alphasort to always have the same order on every system */ |
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if ((n = scandir(path, &namelist, NULL, alphasort)) < 0) { |
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status_error(50, "Internal server error"); |
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errlog("Can't scan %s", path); |
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} else { |
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status(20, "text/gemini"); |
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printf("=> .. ../\n"); /* display link to parent */ |
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for (int j = 0; j < n; j++) { |
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/* skip self and parent */ |
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if ((strcmp(namelist[j]->d_name, ".") == 0) || |
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(strcmp(namelist[j]->d_name, "..") == 0)) { |
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continue; |
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} |
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/* add "/" at the end of a directory path */ |
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if (namelist[j]->d_type == DT_DIR) |
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printf("=> ./%s/ %s/\n", namelist[j]->d_name, namelist[j]->d_name); |
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else |
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printf("=> ./%s %s\n", namelist[j]->d_name, namelist[j]->d_name); |
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free(namelist[j]); |
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} |
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free(namelist); |
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} |
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} |
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void |
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cgi(const char *cgicmd) |
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{ |
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/* run cgicmd replacing current process */ |
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execl(cgicmd, cgicmd, NULL); |
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/* if execl is ok, this will never be reached */ |
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status(42, "Couldn't execute CGI script"); |
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errlog("error when trying to execl %s", cgicmd); |
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exit(1); |
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} |
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void |
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strip_trailing_slash(char *path) |
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{ |
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size_t end = strlen(path); |
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if (end == 0) |
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return; |
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end--; |
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while (path[end] == '/') |
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path[end--] = '\0'; |
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} |
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@ -0,0 +1,27 @@ |
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#ifndef vger_h_INCLUDED |
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#define vger_h_INCLUDED |
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/* length of "gemini://" */ |
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#define GEMINI_PART 9 |
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/*
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* number of bytes to read with fgets() : 2014 + 1. |
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* fgets() reads at most size-1 (1024 here). |
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* See https://gemini.circumlunar.space/docs/specification.html.
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*/ |
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#define GEMINI_REQUEST_MAX 1025 |
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void autoindex(const char *); |
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void cgi (const char *cgicmd); |
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void display_file(const char *); |
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void drop_privileges(const char *, const char *); |
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void echdir (const char *); |
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void status (const int, const char *); |
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void status_redirect(const int, const char *); |
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void status_error(const int, const char *); |
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void strip_trailing_slash(char *path); |
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int uridecode (char *); |
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#endif // vger_h_INCLUDED
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