From 83cd2267b309fa7411acaed356f88101196bb2ad Mon Sep 17 00:00:00 2001
From: Aleksey Veresov <aleksey@veresov.pro>
Date: Thu, 6 Feb 2020 19:43:57 +0300
Subject: [magi] Broken to become better.

---
 src/multipart.c | 479 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 479 insertions(+)
 create mode 100644 src/multipart.c

(limited to 'src/multipart.c')

diff --git a/src/multipart.c b/src/multipart.c
new file mode 100644
index 0000000..0187f7c
--- /dev/null
+++ b/src/multipart.c
@@ -0,0 +1,479 @@
+/* Support for multifile controls are not provided. */
+#include "inner_multipart.h"
+
+#include "error.h"
+#include "inner_tools.h"
+#include "param.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Local Shortcuts
+ */
+static int is_token(char c)
+{
+    return 32 <= c && c <= 126 && !strchr("()<>@,;:\\\"/[]?={} \t", c);
+}
+
+static int is_str_token(char * str)
+{
+    int is = str && *str; /* Empty string is not valid. */
+    while (is && *str) {
+        is = is_token(*str);
+        ++str;
+    }
+    return is;
+}
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Automata for multipart/form-data
+ */
+enum st {
+    st_error = 0,
+    st_begin,
+    st_pname_pre,
+    st_pname,
+    st_pname_end,
+    st_pdata,
+    st_data,
+    st_end
+};
+
+struct automata {
+    struct magi_request * request;
+    struct magi_file      file;
+    struct magi_param     param;
+    struct magi_param     subparam;
+    char *                buf;
+    int                   buf_size;
+    int                   size;
+    int                   len;
+    char *                boundary;
+    int                   boundary_pos;
+    int                   boundary_len;
+    int                   is_end_suspected;
+    int                   is_CR_readed;
+    int                   is_quoted;
+    int                   readed;
+};
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Automata Shortcuts
+ */
+static char * extract_filename(char * n)
+{
+    n = strchr(n, '=');
+    if (!n) {
+        return 0;
+    }
+    n += strspn(n, " \t") + 1;
+    if (*n == '"') {
+        ++n;
+        return magi_str_create_copy(n, n - strchr(n, '"'));
+    } else {
+        return magi_str_create_copy(n, strcspn(n, " \t"));
+    }
+}
+
+static int content_disposition(struct automata * a)
+{
+    char * n = strchr(a->subparam.data, '=');
+    if (!n) {
+        return 0;
+    }
+    n += strspn(n, " \t") + 1;
+    if (*n == '"') {
+        ++n;
+        a->param.name = magi_str_create_copy(n, n - strchr(n, '"'));
+        if (!a->param.name || !*a->param.name) {
+            return 0;
+        }
+    } else {
+        a->param.name = magi_str_create_copy(n, strcspn(n, " \t"));
+        if (!a->param.name || !is_str_token(a->param.name)) {
+            return 0;
+        }
+    }
+    a->file.file_name = extract_filename(n);
+    if (a->file.file_name) {
+        a->file.param_name = a->param.name;
+        a->file.params     = 0;
+        a->param.name      = 0;
+    }
+    free(a->subparam.name);
+    free(a->subparam.data);
+    a->subparam.name = 0;
+    a->subparam.data = 0;
+    return 1;
+}
+
+static int subparam_end(struct automata * a)
+{
+    a->size = 1;
+    a->len  = 0;
+    magi_str_lowercase(a->subparam.name);
+    if (!strcmp(a->subparam.name, "content-disposition")) {
+        return content_disposition(a);
+    } else if (magi_param_list_add(&a->file.params, &a->subparam)) {
+        a->subparam.name = 0;
+        a->subparam.data = 0;
+        return 1;
+    }
+    return 0;
+}
+
+static int param_end(struct automata * a)
+{
+    if (a->file.file_name) {
+        a->request->file_callback(&a->file, a->buf, a->buf_size, 1,
+                                  a->request->file_callback_userdata);
+        a->readed -= a->buf_size;
+        a->buf_size = 0;
+        if (!magi_file_list_add(&a->request->files, &a->file)) {
+            free(a->file.file_name);
+            free(a->file.param_name);
+            magi_param_list_destroy(a->file.params);
+            free(a->file.params);
+            a->request->error = magi_error_multipart;
+            return 0;
+        }
+        a->file.file_name  = 0;
+        a->file.param_name = 0;
+        a->file.params     = 0;
+        a->size            = 1;
+        a->len             = 0;
+        return 1;
+    }
+    if (!a->param.name) {
+        a->request->error = magi_error_multipart;
+        return 0;
+    }
+    if (!magi_param_list_add(&a->request->params, &a->param)) {
+        free(a->param.name);
+        free(a->param.data);
+        a->request->error = magi_error_multipart;
+        return 0;
+    }
+    a->param.name = 0;
+    a->param.data = 0;
+    a->size       = 1;
+    a->len        = 0;
+    return 1;
+}
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Boundary Interfaces
+ */
+static char sepget(const struct automata * a)
+{
+    char      c;
+    const int pos_after = a->boundary_pos - 4 - a->boundary_len;
+    if (a->boundary_pos == 0) {
+        c = '\r';
+    } else if (a->boundary_pos == 1) {
+        c = '\n';
+    } else if (a->boundary_pos == 2 || a->boundary_pos == 3) {
+        c = '-';
+    } else if (a->boundary_pos - 4 < a->boundary_len) {
+        c = a->boundary[a->boundary_pos - 4];
+    } else if (pos_after == 0) {
+        c = '\r';
+    } else if (pos_after == 1) {
+        c = '\n';
+    } else {
+        c = 0;
+    }
+    return c;
+}
+
+static int seplen(const struct automata * a)
+{
+    return a->boundary_len + 6;
+}
+
+static char endget(const struct automata * a)
+{
+    char      c;
+    const int pos_after = a->boundary_pos - 4 - a->boundary_len;
+    if (a->boundary_pos == 0) {
+        c = '\r';
+    } else if (a->boundary_pos == 1) {
+        c = '\n';
+    } else if (a->boundary_pos == 2 || a->boundary_pos == 3) {
+        c = '-';
+    } else if (a->boundary_pos - 4 < a->boundary_len) {
+        c = a->boundary[a->boundary_pos - 4];
+    } else if (pos_after == 0 || pos_after == 1) {
+        c = '-';
+    } else if (pos_after == 2) {
+        c = '\r';
+    } else if (pos_after == 3) {
+        c = '\n';
+    } else {
+        c = 0;
+    }
+    return c;
+}
+
+static int endlen(const struct automata * a)
+{
+    return a->boundary_len + 8;
+}
+
+static int is_semiend(const struct automata * a)
+{ /* Is end readed, expect last two chars, which are CR LF? */
+    return a->is_end_suspected && (a->boundary_pos == endlen(a) - 2);
+}
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Data Reading
+ */
+static void apply_callback(struct automata * a)
+{
+    int full = a->buf_size == a->request->file_callback_addon_max;
+    if (a->file.file_name && full) {
+        a->request->file_callback(&a->file, a->buf, a->buf_size, 0,
+                                  a->request->file_callback_userdata);
+        a->readed -= a->buf_size;
+        a->buf_size = 0;
+    }
+}
+
+static enum st data_add_act(
+    struct automata * a, char c, char ** dest, int * len, int * size)
+{
+    int pos = a->boundary_pos;
+    for (a->boundary_pos = 0; a->boundary_pos < pos; ++a->boundary_pos) {
+        if (a->is_end_suspected) {
+            magi_str_add(dest, len, size, endget(a));
+        } else {
+            magi_str_add(dest, len, size, sepget(a));
+        }
+        apply_callback(a);
+    }
+    a->boundary_pos     = 0;
+    a->is_end_suspected = 0;
+
+    if (sepget(a) != c) {
+        magi_str_add(dest, len, size, c);
+        apply_callback(a);
+        return st_data;
+    } else {
+        a->boundary_pos++;
+        if (a->boundary_pos == seplen(a)) {
+            param_end(a);
+            return st_pname_pre;
+        }
+        return st_data;
+    }
+}
+
+static enum st data_add(struct automata * a, char c)
+{
+    if (a->file.file_name) {
+        int max = a->request->file_callback_addon_max + 1;
+        return data_add_act(a, c, &a->buf, &a->buf_size, &max);
+    } else {
+        return data_add_act(a, c, &a->param.data, &a->len, &a->size);
+    }
+}
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * State analysers
+ */
+static enum st parse_begin(struct automata * a, char c)
+{
+    if (sepget(a) != c) {    /* 'c' is not wanted character from separator; */
+        a->boundary_pos = 0; /* so nullify progress in reading separator. */
+    } else {
+        a->boundary_pos++;
+        if (a->boundary_pos == seplen(a)) {
+            return st_pname_pre; /* Separator is completed, so move on. */
+        }
+    }
+    return st_begin;
+}
+
+static enum st parse_pname_pre(struct automata * a, char c)
+{
+    if (a->is_CR_readed) {
+        if (c != '\n') {
+            return st_error;
+        }
+        a->is_CR_readed = 0;
+        a->boundary_pos = 0;
+        return st_data;
+    } else if (c == '\r') {
+        a->is_CR_readed = 1;
+        return st_pname_pre;
+    } else if (is_token(c) &&
+               magi_str_add(&a->subparam.name, &a->len, &a->size, c)) {
+        return st_pname;
+    }
+    return st_error;
+}
+
+static enum st parse_pname(struct automata * a, char c)
+{
+    if (c == ':') {
+        a->len  = 0;
+        a->size = 1;
+        return st_pdata;
+    } else if (c == ' ' || c == '\t') {
+        return st_pname_end;
+    } else if (is_token(c) &&
+               magi_str_add(&a->subparam.name, &a->len, &a->size, c)) {
+        return st_pname;
+    }
+    return st_error;
+}
+
+static enum st parse_pname_end(struct automata * a, char c)
+{
+    if (c == ':') {
+        a->len  = 0;
+        a->size = 1;
+        return st_pdata;
+    } else if (c == ' ' || c == '\t') {
+        return st_pname_end;
+    }
+    return st_error;
+}
+
+static enum st parse_pdata(struct automata * a, char c)
+{
+    if (a->is_CR_readed) {
+        a->is_CR_readed = 0;
+        if (c == '\n') {
+            if (subparam_end(a)) {
+                return st_pname_pre;
+            }
+            return st_error;
+        } else if (magi_str_add(&a->subparam.data, &a->len, &a->size, '\r') &&
+                   magi_str_add(&a->subparam.data, &a->len, &a->size, c)) {
+            return st_pdata;
+        }
+        return st_error;
+    } else if (c == '\r') {
+        a->is_CR_readed = 1;
+        return st_pdata;
+    } else if (magi_str_add(&a->subparam.data, &a->len, &a->size, c)) {
+        return st_pdata;
+    }
+    return st_error;
+}
+
+static enum st parse_data(struct automata * a, char c)
+{
+    if (a->is_end_suspected) {
+        if (endget(a) != c) {
+            return data_add(a, c);
+        }
+        a->boundary_pos++;
+        if (a->boundary_pos == endlen(a)) {
+            param_end(a);
+            return st_end;
+        }
+        return st_data;
+    } else if (sepget(a) == c) {
+        a->boundary_pos++;
+        if (a->boundary_pos == seplen(a)) {
+            param_end(a);
+            return st_pname_pre;
+        }
+        return st_data;
+    } else if ((a->boundary_pos == seplen(a) - 2) && endget(a) == c) {
+        a->is_end_suspected = 1;
+        a->boundary_pos++;
+        return st_data;
+    }
+    return data_add(a, c);
+}
+
+static enum st parse_end(struct automata * a, char c)
+{
+    return st_end;
+}
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Automata Runner
+ */
+static void run_automata(struct automata * a,
+                         int (*next)(void * next_userdata),
+                         void * next_userdata)
+{
+    enum st state = st_begin;
+    int     c     = next(next_userdata);
+    while (state && state != st_end && c != EOF &&
+           (!a->request->params_max || a->readed != a->request->params_max)) {
+        switch (state) {
+        case st_begin:
+            state = parse_begin(a, c);
+            break;
+        case st_pname_pre:
+            state = parse_pname_pre(a, c);
+            break;
+        case st_pname:
+            state = parse_pname(a, c);
+            break;
+        case st_pname_end:
+            state = parse_pname_end(a, c);
+            break;
+        case st_pdata:
+            state = parse_pdata(a, c);
+            break;
+        case st_data:
+            state = parse_data(a, c);
+            break;
+        case st_end:
+            state = parse_end(a, c);
+        default:
+            break;
+        }
+        c = next(next_userdata);
+        ++a->readed;
+    }
+    if (a->request->params_max && a->readed == a->request->params_max) {
+        a->request->error = magi_error_limit;
+        return;
+    }
+    if (state == st_data && is_semiend(a)) {
+        state = st_end;
+        param_end(a);
+    }
+    if (state != st_end) {
+        a->request->error = magi_error_multipart;
+        free(a->subparam.name);
+        free(a->subparam.data);
+    }
+}
+
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Automata Interfaces
+ */
+void magi_multipart(struct magi_request * request,
+                    char *                boundary,
+                    int (*next)(void * userdata),
+                    void * next_userdata)
+{
+    struct automata a = { 0, { 0, 0, 0 }, { 0, 0 }, { 0, 0 }, 0, 0, 1,
+                          0, 0,           2,        0,        0, 0, 0 };
+    a.request         = request;
+    a.boundary        = boundary;
+    a.boundary_len    = strlen(boundary);
+    a.buf             = malloc(request->file_callback_addon_max + 1);
+    if (a.buf) {
+        run_automata(&a, next, next_userdata);
+        free(a.buf);
+    }
+}
-- 
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