X-Git-Url: https://git.ladys.computer/CGirls/blobdiff_plain/091679702255610d868b06af26ffa0ba5a6bf6d7..f6f2fd79a596ecedaadd8b605b7de9d8c662151c:/request.c

diff --git a/request.c b/request.c
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+++ b/request.c
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+// SPDX-FileCopyrightText: 2025 Lady <https://www.ladys.computer/about/#lady>
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "aa.h"
+#include "request.h"
+
+void cgirls_freereq (cgirls_req req) {
+	free(req.cgirls_project);
+	free(req.cgirls_id);
+	if (req.cgirls_subpath) {
+		size_t i = 0;
+		char* c = req.cgirls_subpath[i];
+		while (c) {
+			free(c);
+			c = req.cgirls_subpath[++i];
+		}
+		free(req.cgirls_subpath);
+	}
+	free(req.cgirls_baseid);
+	free(req.cgirls_status.cgirls_message);
+}
+
+cgirls_req cgirls_path2req(char const*const pathinfo) {
+	assert(pathinfo != nullptr);
+
+	// Initialize the result.
+	cgirls_req req = {
+		.cgirls_action = cgirls_vb_index,
+		.cgirls_type = cgirls_mediatype_any,
+		.cgirls_project = nullptr,
+		.cgirls_id = nullptr,
+		.cgirls_subpath = nullptr,
+		.cgirls_baseid = nullptr,
+		.cgirls_status = {
+			.cgirls_code = 200,
+			.cgirls_message = nullptr,
+		},
+	};
+
+	// `sont´ stores the start of the next term; `eopi´ stores the end of
+	// the `pathinfo´ string, excluding any extension.
+	char const* sont = pathinfo;
+	char const*const eopi = strchr(pathinfo, 0);
+
+	// The portion of the pathinfo which precedes the first slash gives
+	// the project of the request. If there is no first slash, the
+	// project extends to the end of the string. An empty string is
+	// equivalent to having no project.
+	char const* eopj = strchr(sont, '/');
+	if (!eopj) {
+		eopj = eopi;
+	}
+	if (eopj > sont) {
+		req.cgirls_project = strndup(sont, eopj - sont);
+	}
+	if (eopj < eopi) {
+		sont = eopj + 1;
+	} else {
+		sont = eopi;
+	}
+
+  // The portion of the pathinfo which follows the first slash but
+  // precedes the second gives the verb of the request. If there is no
+  // second slash, the verb extends to the end of the string. If the
+  // verb is not present, or is the empty string, it is treated as
+  // `"index"´, unless the second slash is present, in which case it is
+  // treated as `"unknown"´.
+  //
+  // Verbs may be suffixed with one of a small number of extensions to
+  // request a specific type of response.
+  //
+  // Only a few verbs are recognized (corresponding to the `cgirls_vb´
+  // constants). If a verb is present, but unrecognized, it is assigned
+  // the special value `cgirls_vb_unknown´, which should generally be
+  // interpreted as an error.
+	char const* eovb = strchr(sont, '/');
+	if (!eovb) {
+		eovb = eopi;
+	}
+	char const*const eove = eovb;
+	char* verb = nullptr;
+	if (eovb - sont > 4) {
+		// If the verb is at least 5 characters, extract the extension if
+		// present (it will be the last 4), and then set the end of the
+		// verb to the start of the extension.
+		char const* exts = eovb - 4;
+		do {
+			// This “loop” encapsulates extension checking for readability.
+			// If an extension matches, `eovb´ is re·assigned to point to the
+			// beginning of the extension. Otherwise, the loop exits early
+			// and `eovb´ keeps pointing at the end of the string.
+			if (strncmp(exts, ".txt", 4) == 0) {
+				req.cgirls_type = cgirls_mediatype_txt;
+			} else if (strncmp(exts, ".htm", 4) == 0) {
+				req.cgirls_type = cgirls_mediatype_htm;
+			} else if (strncmp(exts, ".xml", 4) == 0) {
+				req.cgirls_type = cgirls_mediatype_xml;
+			} else if (strncmp(exts, ".rdf", 4) == 0) {
+				req.cgirls_type = cgirls_mediatype_rdf;
+			} else {
+				break; // do not re·assign `eovb´
+			}
+			eovb = exts;
+		} while (false);
+	}
+	if (eovb > sont) {
+		verb = strndup(sont, eovb - sont);
+	}
+	if (eove < eopi) {
+		sont = eove + 1;
+	} else {
+		sont = eopi;
+	}
+	if (verb) {
+		if (strcmp(verb, "branches") == 0) {
+			req.cgirls_action = cgirls_vb_branches;
+		} else if (strcmp(verb, "tags") == 0) {
+			req.cgirls_action = cgirls_vb_tags;
+		} else if (strcmp(verb, "show") == 0) {
+			req.cgirls_action = cgirls_vb_show;
+		} else if (strcmp(verb, "raw") == 0) {
+			req.cgirls_action = cgirls_vb_raw;
+		} else if (strcmp(verb, "blame") == 0) {
+			req.cgirls_action = cgirls_vb_blame;
+		} else if (strcmp(verb, "log") == 0) {
+			req.cgirls_action = cgirls_vb_log;
+		} else if (strcmp(verb, "shortlog") == 0) {
+			req.cgirls_action = cgirls_vb_shortlog;
+		} else if (strcmp(verb, "atom") == 0) {
+			req.cgirls_action = cgirls_vb_atom;
+		} else if (strcmp(verb, "patch") == 0) {
+			req.cgirls_action = cgirls_vb_patch;
+		} else if (strcmp(verb, "index") != 0) {
+			req.cgirls_action = cgirls_vb_unknown;
+		}
+		free(verb);
+	} else if (eovb < eopi) {
+		req.cgirls_action = cgirls_vb_unknown;
+	}
+
+  // The portion of the pathinfo which follows the second slash but
+  // precedes the third identifies the identifiers for the request. If
+  // there is no third slash, the identifiers extend to the end of the
+  // string. A single identifier may be given, or two identifiers may
+  // be given separated by two periods. An empty string is equivalent
+  // to no identifier.
+	char const* eoid = strchr(sont, '/');
+	if (!eoid) {
+		eoid = eopi;
+	}
+	char* idid = nullptr;
+	if (eoid > sont) {
+		idid = strndup(sont, eoid - sont);
+	}
+	if (eoid < eopi) {
+		sont = eoid + 1;
+	} else {
+		sont = eopi;
+	}
+	if (idid) {
+		// If the identifier string contains two successive dots, the base
+		// and target identifiers must be extracted and the original
+		// identifier string freed. Otherwise, the identifier string is the
+		// target identifier, and there is no base.
+		char const*const dots = strstr(idid, "..");
+		if (dots) {
+			char const*const eods = dots + 2;
+			char const*const eoii = strchr(idid, 0);
+			if (dots > idid) {
+				req.cgirls_baseid = strndup(idid, dots - idid);
+			}
+			if (eods < eoii) {
+				req.cgirls_id = strndup(eods, eoii - eods);
+			}
+			free(idid);
+		} else {
+			req.cgirls_id = idid;
+		}
+	}
+
+	// The portion of the pathinfo which follows the third slash is the
+	// subpath of the request. An empty sting is equivalent to having no
+	// subpath. Trailing and successive slashes are dropped.
+	char const* soct = sont;
+	char const* psep = nullptr;
+	size_t npth = 0;
+	while (eopi > soct) {
+		// Count the number of segments in the pathinfo so that the correct
+		// amount of space can be allocated.
+		psep = strchr(soct, '/');
+		if (!psep) {
+			psep = eopi;
+		}
+		if (psep > soct) {
+			++npth;
+		}
+		if (eopi > psep) {
+			soct = psep + 1;
+		} else {
+			soct = eopi;
+		}
+	}
+	req.cgirls_subpath = calloc(npth + 1, sizeof(char*));
+	if (!req.cgirls_subpath) {
+		return req;
+	}
+	size_t pthi = 0;
+	while (eopi > sont) {
+		// Add the segments to the newly allocated array.
+		psep = strchr(sont, '/');
+		if (!psep) {
+			psep = eopi;
+		}
+		if (psep > sont) {
+			req.cgirls_subpath[pthi++] = strndup(sont, psep - sont);
+		}
+		if (eopi > psep) {
+			sont = psep + 1;
+		} else {
+			sont = eopi;
+		}
+	}
+	assert(pthi == npth);
+	req.cgirls_subpath[pthi] = nullptr;
+
+	// Return the result.
+	return req;
+}
+
+char* cgirls_req2path(cgirls_req req) {
+	char* action = "unknown";
+	char* extnsn = "";
+	size_t length = 8; // length of `action´ plus 1, to start
+
+	// Get the length of the various parts, saving the verb and the
+	// extension. This length includes a trailing slash, but in practice
+	// this will be replaced by the final null byte.
+	switch (req.cgirls_action) {
+		case cgirls_vb_index:
+			action = "index";
+			length = 6;
+			break;
+		case cgirls_vb_branches:
+			action = "branches";
+			length = 9;
+			break;
+		case cgirls_vb_tags:
+			action = "tags";
+			length = 5;
+			break;
+		case cgirls_vb_show:
+			action = "show";
+			length = 5;
+			break;
+		case cgirls_vb_raw:
+			action = "raw";
+			length = 4;
+			break;
+		case cgirls_vb_blame:
+			action = "blame";
+			length = 6;
+			break;
+		case cgirls_vb_log:
+			action = "log";
+			length = 4;
+			break;
+		case cgirls_vb_shortlog:
+			action = "shortlog";
+			length = 9;
+			break;
+		case cgirls_vb_atom:
+			action = "atom";
+			length = 5;
+			break;
+		case cgirls_vb_patch:
+			action = "patch";
+			length = 6;
+			break;
+		default:
+			break;
+	}
+	switch (req.cgirls_type) {
+		case cgirls_mediatype_txt:
+			extnsn = ".txt";
+			break;
+		case cgirls_mediatype_htm:
+			extnsn = ".htm";
+			break;
+		case cgirls_mediatype_xml:
+			extnsn = ".xml";
+			break;
+		case cgirls_mediatype_rdf:
+			extnsn = ".rdf";
+			break;
+		default:
+			break;
+	}
+	if (req.cgirls_project) {
+		length += strlen(req.cgirls_project) + 1;
+		if (req.cgirls_type != cgirls_mediatype_any) {
+			length += 4;
+		}
+		if (req.cgirls_baseid || req.cgirls_id) {
+			if (req.cgirls_baseid) {
+				length += strlen(req.cgirls_baseid) + 2;
+			}
+			if (req.cgirls_id) {
+				length += strlen(req.cgirls_id);
+			}
+			length += 1;
+		} else if (req.cgirls_subpath && req.cgirls_subpath[0]) {
+			length += 3;
+		}
+		if (req.cgirls_subpath) {
+			size_t i = 0;
+			char* c = req.cgirls_subpath[i];
+			while (c) {
+				length += strlen(c) + 1;
+				c = req.cgirls_subpath[++i];
+			}
+		}
+	} else {
+		// If there is no project, then the action must be removed, and the
+		// length is just that of the trailing slash.
+		length = 1;
+	}
+	// Create and compose the final path.
+	char* result = calloc(length, sizeof(char*));
+	if (!result) {
+		return nullptr;
+	}
+	char* cursor = result;
+	if (req.cgirls_project) {
+		cursor = stpcpy(cursor, req.cgirls_project);
+		(cursor++)[0] = '/';
+		cursor = stpcpy(cursor, action);
+		if (req.cgirls_type != cgirls_mediatype_any) {
+			cursor = stpcpy(cursor, extnsn);
+		}
+		(cursor++)[0] = '/';
+		if (req.cgirls_baseid || req.cgirls_id) {
+			if (req.cgirls_baseid) {
+				cursor = stpcpy(cursor, req.cgirls_baseid);
+				cursor[0] = '.';
+				cursor[1] = '.';
+				cursor += 2;
+			}
+			if (req.cgirls_id) {
+				cursor = stpcpy(cursor, req.cgirls_id);
+			}
+			(cursor++)[0] = '/';
+		} else if (req.cgirls_subpath && req.cgirls_subpath[0]) {
+			cursor = stpcpy(cursor, "../");
+		}
+		if (req.cgirls_subpath) {
+			size_t i = 0;
+			char* c = req.cgirls_subpath[i];
+			while (c) {
+				cursor = stpcpy(cursor, c);
+				c = req.cgirls_subpath[++i];
+				(cursor++)[0] = '/';
+			}
+		}
+	} else {
+		(cursor++)[0] = '/';
+	}
+
+	// At this point, `cursor´ points one ⹐past⹑ the last element of the
+	// array (this is allowed in C), and the last element is a slash.
+	// Rewind and set it to the null byte, and assert that everything was
+	// done correctly.
+	(--cursor)[0] = 0;
+	assert((cursor + 1) - result == length);
+	return result;
+}