initial commit - libgcgi - REST library for Gopher | |
git clone git://bitreich.org/libgcgi git://hg6vgqziawt5s4dj.onion/libgcgi | |
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--- | |
commit 758508d75c969333c3f72f0e01faa0a5129153b9 | |
Author: Josuah Demangeon <[email protected]> | |
Date: Sat, 30 Jul 2022 11:12:39 +0200 | |
initial commit | |
Diffstat: | |
A .gitignore | 1 + | |
A Makefile | 13 +++++++++++++ | |
A index.c | 32 +++++++++++++++++++++++++++++… | |
A libgcgi.h | 336 +++++++++++++++++++++++++++++… | |
4 files changed, 382 insertions(+), 0 deletions(-) | |
--- | |
diff --git a/.gitignore b/.gitignore | |
@@ -0,0 +1 @@ | |
+index.cgi | |
diff --git a/Makefile b/Makefile | |
@@ -0,0 +1,13 @@ | |
+LDFLAGS = -static | |
+CFLAGS = -g -pedantic -std=c99 -Wall -Wextra -Wno-unused-function | |
+ | |
+V = v0.0 | |
+ | |
+all: index.cgi tmp db/category db/item db/image | |
+ | |
+tmp db/category db/item db/image: | |
+ mkdir -p -m 700 $@ | |
+ chown www:www $@ | |
+ | |
+index.cgi: index.c libgcgi.h | |
+ ${CC} ${LDFLAGS} ${CFLAGS} -o $@ index.c | |
diff --git a/index.c b/index.c | |
@@ -0,0 +1,32 @@ | |
+#include <assert.h> | |
+#include <ctype.h> | |
+#include <errno.h> | |
+#include <stdarg.h> | |
+#include <stdint.h> | |
+#include <stdio.h> | |
+#include <stdlib.h> | |
+#include <string.h> | |
+#include <unistd.h> | |
+#include <sys/stat.h> | |
+#include "libgcgi.h" | |
+ | |
+static struct gcgi_handler handlers[] = { | |
+// { "*", error_404 }, | |
+ { NULL, NULL }, | |
+}; | |
+ | |
+int | |
+main(int argc, char **argv) | |
+{ | |
+ /* restrict allowed paths */ | |
+ unveil("gph", "r"); | |
+ unveil("tmp", "rwc"); | |
+ unveil("db", "rwc"); | |
+ | |
+ /* restrict allowed system calls */ | |
+ pledge("stdio rpath wpath cpath", NULL); | |
+ | |
+ /* handle the request with the handlers */ | |
+ gcgi_handle_request(handlers, argv, argc); | |
+ return 0; | |
+} | |
diff --git a/libgcgi.h b/libgcgi.h | |
@@ -0,0 +1,336 @@ | |
+#ifndef LIBGCGI_H | |
+#define LIBGCGI_H | |
+ | |
+/* Gopher CGI library to use in CGI scripts */ | |
+ | |
+/* maps glob pattern */ | |
+struct gcgi_handler { | |
+ char const *glob; | |
+ void (*fn)(char **matches); | |
+}; | |
+ | |
+/* storage for key-value pair */ | |
+struct gcgi_var_list { | |
+ struct gcgi_var { | |
+ char *key, *val; | |
+ } *list; | |
+ size_t len; | |
+ char *buf; | |
+}; | |
+ | |
+/* main loop executing h->fn() if h->glob is matching */ | |
+static void gcgi_handle_request(struct gcgi_handler h[], char **argv, int argc… | |
+ | |
+/* abort the program with an error message sent to the client */ | |
+static void gcgi_fatal(char *fmt, ...); | |
+ | |
+/* receive a file payload from the client onto the disk at `path` */ | |
+static void gcgi_receive_file(char const *path); | |
+ | |
+/* print a template with every "{{name}}" looked up in `vars` */ | |
+static void gcgi_template(char const *path, struct gcgi_var_list *vars); | |
+ | |
+/* print `s` with all gophermap special characters escaped */ | |
+static void gcgi_print_gophermap(char const *s); | |
+ | |
+/* manage a `key`-`val` pair storage `vars`, as used with gcgi_template */ | |
+static void gcgi_add_var(struct gcgi_var_list *vars, char *key, char *val); | |
+static void gcgi_sort_var_list(struct gcgi_var_list *vars); | |
+static void gcgi_set_var(struct gcgi_var_list *vars, char *key, char *val); | |
+static char *gcgi_get_var(struct gcgi_var_list *vars, char *key); | |
+static void gcgi_free_var_list(struct gcgi_var_list *vars); | |
+ | |
+/* store and read a list of variables onto a simple RFC822-like format */ | |
+static void gcgi_read_var_list(struct gcgi_var_list *vars, char *path); | |
+static int gcgi_write_var_list(struct gcgi_var_list *vars, char *path); | |
+ | |
+/* parse various components of the Gopher request */ | |
+static struct gcgi_var_list * gcgi_parse_query_string(void); | |
+ | |
+/* components of the gopher request */ | |
+char *gcgi_gopher_search; | |
+char *gcgi_gopher_path; | |
+char *gcgi_gopher_host; | |
+char *gcgi_gopher_port; | |
+char *gcgi_gopher_args; | |
+ | |
+ | |
+/// POLICE LINE /// DO NOT CROSS /// | |
+ | |
+ | |
+#define GCGI_MATCH_NUM 5 | |
+ | |
+static void | |
+gcgi_fatal(char *fmt, ...) | |
+{ | |
+ va_list va; | |
+ char msg[1024]; | |
+ | |
+ va_start(va, fmt); | |
+ vsnprintf(msg, sizeof msg, fmt, va); | |
+ printf("Status: 500 Server Error\n\n"); | |
+ printf("error: %s\n", msg); | |
+ exit(1); | |
+} | |
+ | |
+static inline char * | |
+gcgi_fopenread(char *path) | |
+{ | |
+ FILE *fp; | |
+ char *buf; | |
+ ssize_t ssz; | |
+ size_t sz; | |
+ | |
+ if ((fp = fopen(path, "r")) == NULL) | |
+ return NULL; | |
+ if (fseek(fp, 0, SEEK_END) == -1) | |
+ return NULL; | |
+ if ((ssz = ftell(fp)) == -1) | |
+ return NULL; | |
+ sz = ssz; | |
+ if (fseek(fp, 0, SEEK_SET) == -1) | |
+ return NULL; | |
+ if ((buf = malloc(sz + 1)) == NULL) | |
+ return NULL; | |
+ if (fread(buf, sz, 1, fp) != sz) | |
+ goto error_free; | |
+ if (ferror(fp)) | |
+ goto error_free; | |
+ fclose(fp); | |
+ buf[sz] = '\0'; | |
+ return buf; | |
+error_free: | |
+ free(buf); | |
+ return NULL; | |
+} | |
+ | |
+static int | |
+gcgi_cmp_var(const void *v1, const void *v2) | |
+{ | |
+ return strcasecmp(((struct gcgi_var *)v1)->key, ((struct gcgi_var *)v2… | |
+} | |
+ | |
+static void | |
+gcgi_add_var(struct gcgi_var_list *vars, char *key, char *val) | |
+{ | |
+ void *mem; | |
+ | |
+ vars->len++; | |
+ if ((mem = realloc(vars->list, vars->len * sizeof *vars->list)) == NUL… | |
+ gcgi_fatal("realloc"); | |
+ vars->list = mem; | |
+ vars->list[vars->len-1].key = key; | |
+ vars->list[vars->len-1].val = val; | |
+} | |
+ | |
+static void | |
+gcgi_sort_var_list(struct gcgi_var_list *vars) | |
+{ | |
+ qsort(vars->list, vars->len, sizeof *vars->list, gcgi_cmp_var); | |
+} | |
+ | |
+static char * | |
+gcgi_get_var(struct gcgi_var_list *vars, char *key) | |
+{ | |
+ struct gcgi_var *v, q = { .key = key }; | |
+ | |
+ v = bsearch(&q, vars->list, vars->len, sizeof *vars->list, gcgi_cmp_va… | |
+ return (v == NULL) ? NULL : v->val; | |
+} | |
+ | |
+static void | |
+gcgi_set_var(struct gcgi_var_list *vars, char *key, char *val) | |
+{ | |
+ struct gcgi_var *v, q; | |
+ | |
+ q.key = key; | |
+ v = bsearch(&q, vars->list, vars->len, sizeof *vars->list, gcgi_cmp_va… | |
+ if (v != NULL) { | |
+ v->val = val; | |
+ return; | |
+ } | |
+ gcgi_add_var(vars, key, val); | |
+ gcgi_sort_var_list(vars); | |
+} | |
+ | |
+static void | |
+gcgi_read_var_list(struct gcgi_var_list *vars, char *path) | |
+{ | |
+ char *line, *tail, *key, *s; | |
+ | |
+ line = NULL; | |
+ | |
+ if ((tail = vars->buf = gcgi_fopenread(path)) == NULL) | |
+ gcgi_fatal("opening %s: %s", path, strerror(errno)); | |
+ while ((line = strsep(&tail, "\n")) != NULL) { | |
+ if (line[0] == '\0') | |
+ break; | |
+ key = strsep(&line, ":"); | |
+ if (line == NULL || *line++ != ' ') | |
+ gcgi_fatal("%s: missing ': ' separator", path); | |
+ gcgi_add_var(vars, key, line); | |
+ } | |
+ gcgi_set_var(vars, "text", tail ? tail : ""); | |
+ gcgi_set_var(vars, "file", (s = strrchr(path, '/')) ? s + 1 : path); | |
+ gcgi_sort_var_list(vars); | |
+} | |
+ | |
+static void | |
+gcgi_free_var_list(struct gcgi_var_list *vars) | |
+{ | |
+ if (vars->buf != NULL) | |
+ free(vars->buf); | |
+ free(vars->list); | |
+} | |
+ | |
+static int | |
+gcgi_write_var_list(struct gcgi_var_list *vars, char *dst) | |
+{ | |
+ FILE *fp; | |
+ struct gcgi_var *v; | |
+ size_t n; | |
+ char path[1024]; | |
+ char *text; | |
+ | |
+ text = NULL; | |
+ | |
+ snprintf(path, sizeof path, "%s.tmp", dst); | |
+ if ((fp = fopen(path, "w")) == NULL) | |
+ gcgi_fatal("opening '%s' for writing", path); | |
+ | |
+ for (v = vars->list, n = vars->len; n > 0; v++, n--) { | |
+ if (strcasecmp(v->key, "Text") == 0) { | |
+ text = text ? text : v->val; | |
+ continue; | |
+ } | |
+ assert(strchr(v->key, '\n') == NULL); | |
+ assert(strchr(v->val, '\n') == NULL); | |
+ fprintf(fp, "%s: %s\n", v->key, v->val); | |
+ } | |
+ fprintf(fp, "\n%s", text ? text : ""); | |
+ | |
+ fclose(fp); | |
+ if (rename(path, dst) == -1) | |
+ gcgi_fatal( "renaming '%s' to '%s'", path, dst); | |
+ return 0; | |
+} | |
+ | |
+static inline int | |
+gcgi_match(char const *glob, char *path, char **matches, size_t m) | |
+{ | |
+ if (m >= GCGI_MATCH_NUM) | |
+ gcgi_fatal("too many wildcards in glob"); | |
+ matches[m] = NULL; | |
+ while (*glob != '*' && *path != '\0' && *glob == *path) | |
+ glob++, path++; | |
+ if (glob[0] == '*') { | |
+ if (*glob != '\0' && gcgi_match(glob + 1, path, matches, m + 1… | |
+ if (matches[m] == NULL) | |
+ matches[m] = path; | |
+ *path = '\0'; | |
+ return 1; | |
+ } else if (*path != '\0' && gcgi_match(glob, path + 1, matches… | |
+ matches[m] = (char *)path; | |
+ return 1; | |
+ } | |
+ } | |
+ return *glob == '\0' && *path == '\0'; | |
+} | |
+ | |
+static void | |
+gcgi_handle_request(struct gcgi_handler h[], char **argv, int argc) | |
+{ | |
+ if (argc != 5) | |
+ gcgi_fatal("wrong number of arguments: %c", argc); | |
+ assert(argv[0] && argv[1] && argv[2] && argv[3]); | |
+ | |
+ /* executable.[d]cgi $search $arguments $host $port */ | |
+ gcgi_gopher_search = argv[1]; | |
+ gcgi_gopher_path = argv[2]; | |
+ gcgi_gopher_host = argv[3]; | |
+ gcgi_gopher_port = argv[4]; | |
+ gcgi_gopher_args = strchr(gcgi_gopher_path, '?'); | |
+ if (gcgi_gopher_args == NULL) { | |
+ gcgi_gopher_args = ""; | |
+ } else { | |
+ *gcgi_gopher_args++ = '\0'; | |
+ } | |
+ | |
+ for (; h->glob != NULL; h++) { | |
+ char *matches[GCGI_MATCH_NUM + 1]; | |
+ if (!gcgi_match(h->glob, gcgi_gopher_path, matches, 0)) | |
+ continue; | |
+ h->fn(matches); | |
+ return; | |
+ } | |
+ gcgi_fatal("no handler for '%s'", gcgi_gopher_path); | |
+} | |
+ | |
+static void | |
+gcgi_print_gophermap(char const *s) | |
+{ | |
+ for (; *s != '\0'; s++) { | |
+ switch(*s) { | |
+ case '<': | |
+ fputs("<", stdout); | |
+ break; | |
+ case '>': | |
+ fputs(">", stdout); | |
+ break; | |
+ case '"': | |
+ fputs(""", stdout); | |
+ break; | |
+ case '\'': | |
+ fputs("'", stdout); | |
+ break; | |
+ case '&': | |
+ fputs("&", stdout); | |
+ break; | |
+ default: | |
+ fputc(*s, stdout); | |
+ } | |
+ } | |
+} | |
+ | |
+static inline char* | |
+gcgi_next_var(char *head, char **tail) | |
+{ | |
+ char *beg, *end; | |
+ | |
+ if ((beg = strstr(head, "{{")) == NULL | |
+ || (end = strstr(beg, "}}")) == NULL) | |
+ return NULL; | |
+ *beg = *end = '\0'; | |
+ *tail = end + strlen("}}"); | |
+ return beg + strlen("{{"); | |
+} | |
+ | |
+static void | |
+gcgi_template(char const *path, struct gcgi_var_list *vars) | |
+{ | |
+ FILE *fp; | |
+ size_t sz; | |
+ char *line, *head, *tail, *key; | |
+ char *val; | |
+ | |
+ sz = 0; | |
+ line = NULL; | |
+ | |
+ if ((fp = fopen(path, "r")) == NULL) | |
+ gcgi_fatal("opening template %s", path); | |
+ | |
+ while (getline(&line, &sz, fp) > 0) { | |
+ head = tail = line; | |
+ for (; (key = gcgi_next_var(head, &tail)); head = tail) { | |
+ fputs(head, stdout); | |
+ if ((val = gcgi_get_var(vars, key))) | |
+ gcgi_print_gophermap(val); | |
+ else | |
+ fprintf(stdout, "{{error:%s}}", key); | |
+ } | |
+ fputs(tail, stdout); | |
+ } | |
+ fclose(fp); | |
+} | |
+ | |
+#endif |